Subjects -> INSTRUMENTS (Total: 63 journals)
Showing 1 - 16 of 16 Journals sorted alphabetically
Annali dell'Istituto e Museo di storia della scienza di Firenze     Hybrid Journal  
Applied Mechanics Reviews     Full-text available via subscription   (Followers: 27)
Bulletin of Social Informatics Theory and Application     Open Access   (Followers: 1)
Computational Visual Media     Open Access   (Followers: 4)
Devices and Methods of Measurements     Open Access  
Documenta & Instrumenta - Documenta et Instrumenta     Open Access  
EPJ Techniques and Instrumentation     Open Access  
European Journal of Remote Sensing     Open Access   (Followers: 9)
Experimental Astronomy     Hybrid Journal   (Followers: 39)
Flow Measurement and Instrumentation     Hybrid Journal   (Followers: 18)
Geoscientific Instrumentation, Methods and Data Systems     Open Access   (Followers: 4)
Geoscientific Instrumentation, Methods and Data Systems Discussions     Open Access   (Followers: 1)
IEEE Journal on Miniaturization for Air and Space Systems     Hybrid Journal   (Followers: 2)
IEEE Sensors Journal     Hybrid Journal   (Followers: 103)
IEEE Sensors Letters     Hybrid Journal   (Followers: 3)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Imaging & Microscopy     Hybrid Journal   (Followers: 9)
InfoTekJar : Jurnal Nasional Informatika dan Teknologi Jaringan     Open Access  
Instrumentation Science & Technology     Hybrid Journal   (Followers: 7)
Instruments and Experimental Techniques     Hybrid Journal   (Followers: 1)
International Journal of Applied Mechanics     Hybrid Journal   (Followers: 7)
International Journal of Instrumentation Science     Open Access   (Followers: 40)
International Journal of Measurement Technologies and Instrumentation Engineering     Full-text available via subscription   (Followers: 2)
International Journal of Metrology and Quality Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Remote Sensing     Hybrid Journal   (Followers: 278)
International Journal of Remote Sensing Applications     Open Access   (Followers: 45)
International Journal of Sensor Networks     Hybrid Journal   (Followers: 4)
International Journal of Testing     Hybrid Journal   (Followers: 1)
Journal of Applied Remote Sensing     Hybrid Journal   (Followers: 83)
Journal of Astronomical Instrumentation     Open Access   (Followers: 3)
Journal of Instrumentation     Hybrid Journal   (Followers: 32)
Journal of Instrumentation Technology & Innovations     Full-text available via subscription   (Followers: 2)
Journal of Medical Devices     Full-text available via subscription   (Followers: 5)
Journal of Medical Signals and Sensors     Open Access   (Followers: 3)
Journal of Optical Technology     Full-text available via subscription   (Followers: 5)
Journal of Sensors and Sensor Systems     Open Access   (Followers: 11)
Journal of Vacuum Science & Technology B     Hybrid Journal   (Followers: 3)
Jurnal Informatika Upgris     Open Access  
Measurement : Sensors     Open Access   (Followers: 3)
Measurement and Control     Open Access   (Followers: 36)
Measurement Instruments for the Social Sciences     Open Access  
Measurement Science and Technology     Hybrid Journal   (Followers: 7)
Measurement Techniques     Hybrid Journal   (Followers: 3)
Medical Devices & Sensors     Hybrid Journal  
Medical Instrumentation     Open Access  
Metrology and Instruments / Метрологія та прилади     Open Access  
Metrology and Measurement Systems     Open Access   (Followers: 6)
Microscopy     Hybrid Journal   (Followers: 8)
Modern Instrumentation     Open Access   (Followers: 50)
Optoelectronics, Instrumentation and Data Processing     Hybrid Journal   (Followers: 4)
PFG : Journal of Photogrammetry, Remote Sensing and Geoinformation Science     Hybrid Journal  
Photogrammetric Engineering & Remote Sensing     Full-text available via subscription   (Followers: 29)
Remote Sensing     Open Access   (Followers: 55)
Remote Sensing Applications : Society and Environment     Full-text available via subscription   (Followers: 8)
Remote Sensing of Environment     Hybrid Journal   (Followers: 93)
Remote Sensing Science     Open Access   (Followers: 24)
Review of Scientific Instruments     Hybrid Journal   (Followers: 22)
Science of Remote Sensing     Open Access  
Sensors and Materials     Open Access   (Followers: 2)
Solid State Nuclear Magnetic Resonance     Hybrid Journal   (Followers: 3)
Standards     Open Access  
Transactions of the Institute of Measurement and Control     Hybrid Journal   (Followers: 13)
Труды СПИИРАН     Open Access  
Similar Journals
Journal Cover
Review of Scientific Instruments
Journal Prestige (SJR): 0.585
Citation Impact (citeScore): 1
Number of Followers: 22  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0034-6748 - ISSN (Online) 1089-7623
Published by AIP Homepage  [27 journals]
  • Influence of the tilt error motion of the rotation axis on the test of the
           equivalence principle with a rotating torsion pendulum
    • Authors: Hui-Hui Zhao, Lu Ding, Lin Zhu, Qi Liu, Wen-Hai Tan, Cheng-Gang Shao, Pengshun Luo, Shan-Qing Yang, Liang-Cheng Tu, Jun Luo
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Improving the precision of current tests of the equivalence principle with a rotating torsion pendulum requires a more complete analysis of systematic effects. Here, we discuss in detail one of the important systematic effects, the influence from the tilt error motion of the rotation axis of a rotary stage, namely, wandering of the instantaneous rotation axis around its average direction. Its influence on the rotating torsion pendulum is modeled phenomenologically, and the parameters in the model are calibrated. It is shown that the influence can contribute a correction of η ≈ 5 × 10−13 to the equivalence-principle violating parameter for a rotary stage whose tilt error motion of interest is about 31 nrad in magnitude. We also show that such an influence can be reduced to the level of η ≈ 1 × 10−14 by means of active compensation of the tilt error motion using a set of piezoelectric actuators placed under the stage stator.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:46Z
      DOI: 10.1063/5.0023420
       
  • Faster high-speed atomic force microscopy for imaging of biomolecular
           processes
    • Authors: Shingo Fukuda, Toshio Ando
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      High-speed atomic force microscopy (HS-AFM) has enabled observing protein molecules during their functional activity at rates of 1–12.5 frames per second (fps), depending on the imaging conditions, sample height, and fragility. To meet the increasing demand for the great expansion of observable dynamic molecular processes, faster HS-AFM with less disturbance is imperatively needed. However, even a 50% improvement in the speed performance imposes tremendous challenges, as the optimization of major rate-limiting components for their fast response is nearly matured. This paper proposes an alternative method that can lower the feedback control error and thereby enhance the imaging rate. This method can be implemented in any HS-AFM system by minor modifications of the software and hardware. The resulting faster and less-disturbing imaging capabilities are demonstrated by the imaging of relatively fragile actin filaments and microtubules near the video rate, and of actin polymerization that occurs through weak intermolecular interactions, at ∼8 fps.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:45Z
      DOI: 10.1063/5.0032948
       
  • Q-band high-performance notch filters at 56 and 77 GHz notches for
           versatile fusion plasma diagnostics
    • Authors: M. Nishiura, T. Shimizu, S. Kobayashi, T. Tokuzawa, K. Ichinose, S. Kubo
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A six-pole Q-band waveguide filter with a notch frequency above the Q-band has been developed for plasma diagnostics. The previous paper [Nishiura et al., J. Instrum. 10, C12014 (2015)] reported that the notch frequency exists within the standard band. In this study, the newly required notch filter extends the function, which prevents a thorny wave from being mixed into an instrument beyond the standard bandwidth of the waveguide. The mode control technique for cavities realizes a deep and sharp filter shape for Q-band notch filters with 56 and 77 GHz notches, respectively. The former filter has an attenuation more than 50 dB at 56.05 GHz and a bandwidth of 1.1 GHz at −3 dB. The latter filter has an attenuation more than 55 dB at 76.95 GHz and a bandwidth of 1.6 GHz at −3 dB. The electron cyclotron emission imaging and the electron cyclotron emission (ECE) diagnostics for the Q-band implemented a pair of the fabricated filters and demonstrated the ECE measurement successfully in the intense stray radiation from a 56 GHz gyrotron.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:44Z
      DOI: 10.1063/5.0041243
       
  • Response to “Comment on ‘Requirements and sensitivity analysis for
           temporally- and spatially-resolved thermometry using neutron resonance
           spectroscopy’” [Rev. Sci. Instrum. 90, 094901 (2019)]
    • Authors: Juan C. Fernández, Cris W. Barnes, Michael J. Mocko, Lukas Zavorka
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.

      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:42Z
      DOI: 10.1063/5.0015934
       
  • Active control of electron cyclotron emission radiometer channel
           frequencies for improved electron temperature measurements
    • Authors: R. Xie, S. Houshmandyar, M. E. Austin
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      As advanced scenarios are developed for tokamak operations, the demand for flexibility of the electron cyclotron emission (ECE) channels’ locations has increased. The tunable feature of yttrium iron garnet (YIG) filters provides this spatial flexibility. Here, we present a method of performing ECE measurements on fixed flux surfaces instead of fixed frequencies. This is achieved by adjusting YIG filters utilized in the intermediate frequency section to frequencies associated with flux surfaces in regions of interest during the discharge. The key components are the application of tunable YIG filters and a control program that calculates the filter settings using flux information from real-time reconstruction equilibria (EFIT). This fast procedure facilitates Te measurements in regions of interest to investigate plasma dynamic behaviors.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:41Z
      DOI: 10.1063/5.0043662
       
  • Neural network surrogates of Bayesian diagnostic models for fast inference
           of plasma parameters
    • Authors: A. Pavone, J. Svensson, M. Krychowiak, U. Hergenhahn, V. Winters, P. Kornejew, S. Kwak, U. Hoefel, R. Koenig, R. C. Wolf
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We present a framework for training artificial neural networks (ANNs) as surrogate Bayesian models for the inference of plasma parameters from diagnostic data collected at nuclear fusion experiments, with the purpose of providing a fast approximation of conventional Bayesian inference. Because of the complexity of the models involved, conventional Bayesian inference can require tens of minutes for analyzing one single measurement, while hundreds of thousands can be collected during a single plasma discharge. The ANN surrogates can reduce the analysis time down to tens/hundreds of microseconds per single measurement. The core idea is to generate the training data by sampling them from the joint probability distribution of the parameters and observations of the original Bayesian model. The network can be trained to learn the reconstruction of plasma parameters from observations and the model joint probability distribution from plasma parameters and observations. Previous work has validated the application of such a framework to the former case at the Wendelstein 7-X and Joint European Torus experiments. Here, we first give a description of the general methodological principles allowing us to generate the training data, and then we show an example application of the reconstruction of the joint probability distribution of an effective ion charge Zeff-bremsstrahlung model from data collected at the latest W7-X experimental campaign. One key feature of such an approach is that the network is trained exclusively on data generated with the Bayesian model, requiring no experimental data. This allows us to replicate the training scheme and generate fast, surrogate ANNs for any validated Bayesian diagnostic model.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:38Z
      DOI: 10.1063/5.0043772
       
  • Anti-reflection coated vacuum window for the Primordial Inflation
           Polarization ExploreR (PIPER) balloon-borne instrument
    • Authors: Rahul Datta, David T. Chuss, Joseph Eimer, Thomas Essinger-Hileman, Natalie N. Gandilo, Kyle Helson, Alan J. Kogut, Luke Lowe, Paul Mirel, Karwan Rostem, Marco Sagliocca, Danielle Sponseller, Eric R. Switzer, Peter A. Taraschi, Edward J. Wollack
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Measuring the faint polarization signal of the cosmic microwave background (CMB) not only requires high optical throughput and instrument sensitivity but also control over systematic effects. Polarimetric cameras or receivers used in this setting often employ dielectric vacuum windows, filters, or lenses to appropriately prepare light for detection by cooled sensor arrays. These elements in the optical chain are typically designed to minimize reflective losses and hence improve sensitivity while minimizing potential imaging artifacts such as glint and ghosting. The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument designed to measure the polarization of the CMB radiation at the largest angular scales and characterize astrophysical dust foregrounds. PIPER’s twin telescopes and detector systems are submerged in an open-aperture liquid helium bucket dewar. A fused-silica window anti-reflection (AR) coated with polytetrafluoroethylene is installed on the vacuum cryostat that houses the cryogenic detector arrays. Light passes from the skyward portions of the telescope to the detector arrays through this window, which utilizes an indium seal to prevent superfluid helium leaks into the vacuum cryostat volume. The AR coating implemented reduces reflections from each interface to
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:38Z
      DOI: 10.1063/5.0029430
       
  • An in situ microtomography apparatus with a laboratory x-ray source for
           elevated temperatures of up to 1000 °C
    • Authors: Rongqi Zhu, Zhaoliang Qu, Shuo Yang, Daining Fang
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      An elevated-temperature in situ microtomography apparatus that can measure internal damage parameters under tensile loads at high temperatures up to 1000 °C is developed using a laboratory x-ray source. The maximum resolution of the apparatus can reach 3 µm by a reasonable design. A high-temperature environment is accomplished by means of a heating chamber based on a radiation technique using four halogen lamps with ellipsoidal reflectors. To obtain high resolution, the chamber is much smaller in the direction of the x-ray beam than in the other two directions. Two thin aluminum windows are chosen as the chamber walls perpendicular to and intersecting the x-ray beam. A material testing machine equipped with two synchronous rotating motors is specially designed for mechanical loading and 360° rotation of the specimen, and customized grips are developed to conduct tensile tests. A microfocus x-ray source and a high-resolution detector are used to produce and detect X rays, and the distances among the x-ray source, specimen, and high-resolution detector can be adjusted to obtain different resolutions. To show the main functions and usability of the apparatus, carbon-fiber-reinforced silicon-carbide matrix specimens are subjected to in situ x-ray microtomography tensile tests at 800 °C and 1000 °C, and the crack propagation behavior under thermomechanical coupling loads is studied.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-12T01:49:37Z
      DOI: 10.1063/5.0038026
       
  • Automated wide-ranged finely tunable microwave cavity for narrowband phase
           noise filtering
    • Authors: Yash J. Joshi, Nick Sauerwein, Amir Youssefi, Philipp Uhrich, Tobias J. Kippenberg
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Narrowband microwave filters have wide ranging applications, including the reduction in phase noise of microwave sources within a given frequency band. The prospect of developing an automated filter that tunes itself to an arbitrary desired frequency at maximum extinction promises many experimental advantages such as an enhanced efficiency in performing fine frequency detuning scans and saving time and effort as compared to manual tuning. We design, construct, and program such an automated system and present its hardware and software for reproducibility. It consists of a cylindrical cavity filter and two motors, which change the cavity length and the coupling strength of the microwave field into the cavity, respectively. By measuring the cavity response, an algorithm implemented in Python optimizes these two parameters to achieve the tuning of the filter cavity to the desired frequency with a precision of around 20 kHz, which is significantly better than the cavity linewidth (∼1 MHz). We also demonstrate the suppression of phase noise at the desired frequency by more than 10 dB.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:24Z
      DOI: 10.1063/5.0034696
       
  • Characterizing cryogenic amplifiers with a matched temperature-variable
           noise source
    • Authors: Slawomir Simbierowicz, Visa Vesterinen, Joshua Milem, Aleksi Lintunen, Mika Oksanen, Leif Roschier, Leif Grönberg, Juha Hassel, David Gunnarsson, Russell E. Lake
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We present a cryogenic microwave noise source with a characteristic impedance of 50 Ω, which can be installed in a coaxial line of a cryostat. The bath temperature of the noise source is continuously variable between 0.1 K and 5 K without causing significant back-action heating on the sample space. As a proof-of-concept experiment, we perform Y-factor measurements of an amplifier cascade that includes a traveling wave parametric amplifier and a commercial high electron mobility transistor amplifier. We observe system noise temperatures as low as [math] mK at 5.7 GHz corresponding to [math] excess photons. The system we present has immediate applications in the validation of solid-state qubit readout lines.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:22Z
      DOI: 10.1063/5.0028951
       
  • STARGATE: A new instrument for high-resolution photodissociation
           spectroscopy of cold ionic species
    • Authors: Raghed Bejjani, Anthony Roucou, Xavier Urbain, Konstantin Moshkunov, Guilhem Vanlancker, Clément Lauzin
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Spectroscopy of transient anions and radicals by gated and accelerated time-of-flight experiment is a new spectrometer developed in UCLouvain. This instrument measures high-resolution photodissociation spectra of mass-selected ions by the combination of a time-of-flight spectrometer including a specific gating, bunching, and re-referencing unit with a nanosecond pulsed dye laser, a pulsed deflection, and an energy selector. The ionic species are generated in a supersonic jet expansion by means of an electric discharge or by the impact of electrons coming from an electron gun. The versatility of the molecular systems that can be addressed by this instrument is illustrated by the presentation of mass spectra of cations, anions, and ionic clusters formed from different gas mixtures and backing pressures. The high-resolution spectrum of the [math] and [math] rovibronic bands of N2O+ has been measured and analyzed to provide refined molecular parameters in the [math] upper state. The [math] band has been used to evaluate the quality of the experimental setup in terms of rotational temperature, time of measurement for certain signal to noise ratio, and the accuracy of the determination of the wavenumber scale.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:18Z
      DOI: 10.1063/5.0039627
       
  • A transmitted-beam diagnostic for the wavelength-tunable UV drive beam on
           OMEGA
    • Authors: J. Katz, D. Turnbull, B. E. Kruschwitz, A. L. Rigatti, R. Rinefierd, D. H. Froula
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A transmitted-beam diagnostic (P9TBD) was developed as part of a new experimental platform used to study laser–plasma interactions on OMEGA. Located in the opposing port to the wavelength-tunable (350 nm to 353 nm) UV drive beam, the P9TBD characterizes the beam after it propagates through an undersense plasma. The instrument consists of a large-aperture window that allows light to exit the target chamber and project onto a thin sheet of semi-transparent diffuser material. Light transmitted through the diffuser is recorded using a time-integrated camera and a fiber-optically coupled streaked spectrometer, providing measurements of the energy, power, fluence, polarization, and spectrum of the transmitted beam. The diagnostic enables direct observation of a variety of cross-beam energy transfer phenomena, such as wavelength detuning, polarization effects, and gain saturation.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:17Z
      DOI: 10.1063/5.0042877
       
  • Feedback-controlled microbubble generator producing 1 × 106
           monodisperse bubbles per second
    • Authors: Benjamin van Elburg, Gonzalo Collado-Lara, Gert-Wim Bruggert, Tim Segers, Michel Versluis, Guillaume Lajoinie
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Monodisperse lipid-coated microbubbles are a promising route to unlock the full potential of ultrasound contrast agents for medical diagnosis and therapy. Here, we present a stand-alone lab-on-a-chip instrument that allows microbubbles to be formed with high monodispersity at high production rates. Key to maintaining a long-term stable, controlled, and safe operation of the microfluidic device with full control over the output size distribution is an optical transmission-based measurement technique that provides real-time information on the production rate and bubble size. We feed the data into a feedback loop and demonstrate that this system can control the on-chip bubble radius (2.5 μm–20 μm) and the production rate up to 106 bubbles/s. The freshly formed phospholipid-coated bubbles stabilize after their formation to a size approximately two times smaller than their initial on-chip bubble size without loss of monodispersity. The feedback control technique allows for full control over the size distribution of the agent and can aid the development of microfluidic platforms operated by non-specialist end users.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:15Z
      DOI: 10.1063/5.0032140
       
  • Absolute response of a Fuji BAS-TR imaging plate to low-energy protons (
    • Authors: Sadaoki Kojima, Tatsuhiko Miyatake, Shunsuke Inoue, Thanh Hung Dinh, Noboru Hasegawa, Michiaki Mori, Hironao Sakaki, Mamiko Nishiuchi, Nicholas P. Dover, Yoichi Yamamoto, Teru Sasaki, Fuyumi Ito, Kotaro Kondo, Takashi Yamanaka, Masaki Hashida, Shuji Sakabe, Masaharu Nishikino, Kiminori Kondo
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This paper reports on the absolute response of a Fuji BAS-TR image plate to relatively low-energy protons (
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:11Z
      DOI: 10.1063/5.0035618
       
  • Time-dependent soft and hard x-ray measurements using streak and x-ray
           diode array diagnostic systems
    • Authors: Z. Shpilman, S. Silberstein, D. Rubin, Y. Ehrlich, Z. Oysher, Y. Ferber, I. Levy
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      High-temperature, high-density experiments require a simultaneous understanding of temporal and spectral regions. The spectral x-ray streak camera (SXSC) is a new high-temporal-resolution spectral x-ray diagnostic system that allows researchers to differentiate between soft and hard x-ray regions. The diagnostic offers three spectral channels with a wide spectral range, one direct channel that includes a filter and two indirect channels that include both mirrors and filters. The opto-mechanical design positions the filtered radiation at three different locations along the streak photo-cathode (PC) slit to provide time-dependent spectral channels with pico-second temporal resolution. A moderate spatial resolution (150–700 μm) is achieved using slits perpendicular to the PC slit, while the slit width is optimized according to the central channel wavelength (for each channel). The diagnostic system covers a spectral range of 30–500 eV for the mirror channels and>1300 eV for the direct channel. The temporal and spatial axes of the streak camera are calibrated with respect to a sequence of x-ray pulses. The SXSC diagnostic system is tested and analyzed using Marshak-wave emission from an SiO2 foam that was heated by a laser-beam irradiated halfraum. The SXSC results are compared to measurements from an x-ray diode array with similar spectral channels.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:10Z
      DOI: 10.1063/5.0040581
       
  • An 18.3 MJ charging and discharging pulsed power supply system for the
           Space Plasma Environment Research Facility (SPERF): Modular design method
           and component selection
    • Authors: Peng E, Jian Guan, Wenbin Ling, Xun Ma, Aohua Mao, Weijun Deng, Mingjun Ding, Songjie Li, Chuanhui Kang, Hongtao Li
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The capacitor-based pulsed power supply (PPS) system is an important subsystem of the Space Plasma Environment Research Facility being built as a user facility at Harbin Institute of Technology in China. It has been developed with a modular design to drive magnetic coils to generate magnetic fields and plasma for the physical experiments. In this paper, the modular design and component selection are proposed based on a calculation of parameter ranges of components and the number of modules followed by a simulation and an engineering test. Both the simulation and test results show the feasibility of the selected components and the number of modules to meet the designing requirements of the PPS.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:09Z
      DOI: 10.1063/5.0036923
       
  • Toward 3D data visualization using virtual reality tools
    • Authors: J. L. Kline, P. L. Volegov
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Virtual Reality (VR) offers the opportunity to display data, instrumentation, and experimental setups in three dimensions and gives the user the ability to interact with the objects. This technology moves visualization beyond two-dimensional projections on a flat screen with a fixed field of view in which a keyboard or another similar controller is needed to change the view. Advances in both hardware and software for VR make it possible for the non-expert to develop visualization tools for scientific applications both for viewing and for sharing data or diagnostic hardware between users in three dimensions. This manuscript describes application development using two VR software tools, Unity gaming engine and A-frame, for visualizing data and high energy physics targets.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:08Z
      DOI: 10.1063/5.0040468
       
  • Reconstructing 3D asymmetries in laser-direct-drive implosions on OMEGA
    • Authors: O. M. Mannion, K. M. Woo, A. J. Crilly, C. J. Forrest, J. A. Frenje, M. Gatu Johnson, V. Yu. Glebov, J. P. Knauer, Z. L. Mohamed, M. H. Romanofsky, C. Stoeckl, W. Theobald, S. P. Regan
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Three-dimensional reconstruction algorithms have been developed, which determine the hot-spot velocity, hot-spot apparent ion temperature distribution, and fuel areal-density distribution present in laser-direct-drive inertial confinement fusion implosions on the OMEGA laser. These reconstructions rely on multiple independent measurements of the neutron energy spectrum emitted from the fusing plasma. Measurements of the neutron energy spectrum on OMEGA are made using a suite of quasi-orthogonal neutron time-of-flight detectors and a magnetic recoil spectrometer. These spectrometers are positioned strategically around the OMEGA target chamber to provide unique 3D measurements of the conditions of the fusing hot spot and compressed fuel near peak compression. The uncertainties involved in these 3D reconstructions are discussed and are used to identify a new nTOF diagnostic line of sight, which when built will reduce the uncertainty in the hot-spot apparent ion temperature distribution from 700 to
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-11T11:07:02Z
      DOI: 10.1063/5.0043514
       
  • A CMOS Hall sensor modeling with readout circuitry and microcontroller
           processing for magnetic detection
    • Authors: Hua Fan, Jiayi Zhang, Siming Zuo, Qiang Hu, Quanyuan Feng, Hadi Heidari
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A Hall sensor array system for magnetic field detection and analysis is realized in X-FAB 0.18 μm CMOS technology. Magnetic field detection is attributed to the magnetization of metal coils to metal particles and the sensing characteristics of the Hall sensor array. The system puts forward a complete solution from Hall sensors, analog front-end circuit, analog-to-digital converter (ADC) to microcontroller unit. Using Ansoft Maxwell and COMSOL Multiphysics software for simulation verification, the minimum diameter of magnetic particles that can be detected in the system is 2 μm. The measured signal to noise and distortion ratio, spurious free dynamic range, and effective number of bits of the proposed ADC are 70.61 dB, 90.08 dB, and 11.44-bit, respectively. The microsystem based on STM32 combines hardware and software design, which can effectively adjust the motion parameters and realize the real-time display in the LCD screen of the magnetic field and voltage information. Compared to the prior system, the portability, cost, and efficiency have been considerably improved, which is aimed at the rapid measurement of heavy metal particles such as Fe, Co, and Ni in ambient air and blood.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:37Z
      DOI: 10.1063/5.0038295
       
  • Optimal design of a driver of interdigital transducers used to generate
           standing surface acoustic waves for cell sorting
    • Authors: Zhiguo Pei, Yuting Ma, Ce Wang, Yunliang Wu, Feifei Song, Xiaodong Wu
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A compact driver based on current feedback amplifiers is designed to drive interdigital transducers (IDTs) that generate standing surface acoustic waves for cell sorting. Compared with commercial RF amplifiers, this driver can be used to drive a wider range of loads without impedance matching. Furthermore, the driver works in a switch mode triggered by target cells, which significantly reduces power consumption in the system. A Butterworth–Van Dyke equivalent circuit was fabricated to study the electrical characteristics of the IDTs, and the driver was designed and optimized by circuit simulations. A cell sorter was constructed and tested experimentally to demonstrate that the driver meets sorting requirements. The driver allows the cell sorter to extract rare cells while otherwise consuming low power.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:36Z
      DOI: 10.1063/5.0036856
       
  • Measuring the phase noise of Raman lasers with an atom-based method
    • Authors: Yaning Wang, Shuhua Yan, Dongyang Xu, Mei Hu, Qixue Li, Xu Zhang, Huankai Zhang, Mengjie Lv, Aiai Jia, Guochao Wang, Lingxiao Zhu, Jun Yang
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Phase noise of Raman lasers is a major source of noise for a Raman-type cold atom interferometer, which is traditionally measured using the signal source analyzer. We report here an atom-based method to measure the phase noise performance between two Raman lasers. By analyzing and calibrating the system noise sources, we can characterize the contribution of phase noise from the total deviation of the relative atom population at the middle of the interference fringe. Knowing the transfer function specified by the operation sequence of the interferometer, we can obtain the transfer function and power spectrum density of the phase noise term. By varying the time sequences of the interferometer, we can measure the white phase noise floor and the phase noise performance over a large range of Fourier frequencies from 1 to 100 000 Hz with a minor difference of 1 dB compared with results from the traditional method using a signal analyzer, which proves the validity of the atom-based method. Compared with the traditional measurement method, the atom-based method can have higher accuracy and have the ability of self-calibrating.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:35Z
      DOI: 10.1063/5.0037422
       
  • A low noise transimpedance amplifier for optical receiver
    • Authors: Chenming Li, Sheng Xie, Gaolei Zhou, Luhong Mao, Bowen Qiu
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      In this paper, a regulated cascode (RGC) structure and a shunt-feedback transimpedance amplifier are cascaded. By analyzing the average input-referred noise current, this paper used the method of adjusting the metal–oxide–semiconductor size and increasing the transimpedance gain to optimize the circuit noise characteristics without introducing redundant structures and noise sources. The measured results demonstrated that when the photodetector capacitance is 300 pF and the supply voltage is 1.8 V, the fabricated transimpedance amplifier has a transimpedance gain of 59.5 dBΩ and a −3 dB bandwidth of 4 GHz. Simultaneously, the average input-referred noise current spectral density is less than 7 pA/√Hz, and the data rate is as high as 5 Gb/s. The circuit takes advantage of the traditional shunt-feedback transimpedance amplifier and introduces a RGC structure between it and the input terminal as a current buffer structure. A π-type matching network was formed by adding an inductor between the shunt-feedback amplifier and the introduced RGC. All these structures can effectively improve the gain–bandwidth product of the designed amplifier.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:34Z
      DOI: 10.1063/5.0031658
       
  • Highly accessible low-loss fiber tapering by the ceramic housed electric
           furnace (CHEF) and frequency-domain real-time monitoring
    • Authors: Yundong Ren, Mucheng Li, Subhrodeep Ray, Brandon Johann Bozeat, Yuxiang Liu
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Tapered optical fibers are versatile tools with a wide spectrum of applications, ranging from sensing to atomic physics. In this work, we developed a highly accessible and controllable fiber tapering system to fabricate tapered optical fibers with a routine optical transmission of 95% and above. With an optimal design, optical transmissions higher than 99% have been experimentally demonstrated. We achieved such results by developing two unique components in a traditional heat-and-pull system: a custom-made miniature heater named as the ceramic housed electric furnace (CHEF) and a real-time, frequency-domain monitoring method. The CHEF enables a well-controlled, uniform, and stable heating zone for an adiabatic tapering process, while the frequency-domain monitoring empowers one to reliably terminate the tapering right after the single-mode trigger. We designed and fabricated the CHEF using low-cost and readily accessible materials and equipment, in order to benefit a broader audience. We carried out a parametric study to systematically characterize the CHEF performance and provided guidelines for the CHEF design, fabrication, and operation. The frequency-domain monitoring method was developed based on our understanding of the dynamic evolution of optical modes in the tapered fiber. Such a method allows real-time visualization of the number of optical models and characterization of the taper adiabaticity during the tapering process, both of which are not available with the commonly used time-domain monitoring. The developed CHEF-based fiber tapering system will meet the urgent need of high-quality tapered optical fibers as well as opening doors to new applications of tapered optical fibers.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:34Z
      DOI: 10.1063/5.0023832
       
  • Upgrades and redesign of the National Ignition Facility’s soft x-ray
           opacity spectrometer (OpSpec)
    • Authors: M. S. Wallace, R. F. Heeter, R. A. Knight, A. M. Durand, J. M. Heinmiller, R. B. Lara, D. A. Max, E. C. Dutra, E. J. Huffman, J. Ayers, J. A. Emig, T. N. Archuleta, T. J. Urbatsch, T. S. Perry
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The soft x-ray Opacity Spectrometer (OpSpec) used on the National Ignition Facility (NIF) has recently incorporated an elliptically shaped crystal. The original OpSpec used two convex cylindrical crystals for time-integrated measurements of point-projection spectra from 540 to 2100 eV. However, with the convex geometry, the low-energy portion of the spectrum suffered from high backgrounds due to scattered x-rays as well as reflections from alternate crystal planes. An elliptically shaped crystal allows an acceptance aperture at the crossover focus between the crystal and the detector, which reduces background and eliminates nearly all reflections from alternate crystal planes. The current elliptical design is an improvement from the convex cylindrical design but has a usable energy range from 900 to 2100 eV. In addition, OpSpec is currently used on 18 NIF shots/year, in which both crystals are typically damaged beyond reuse, so efficient production of 36 crystals/year is required. Design efforts to improve the existing system focus on mounting reliability, reducing crystal strain to increase survivability between mounting and shot time, and extending the energy range of the instrument down to 520 eV. The elliptical design, results, and future options are presented.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:33Z
      DOI: 10.1063/5.0043517
       
  • Self-referencing circular dichroism ion yield measurements for improved
           statistics using femtosecond laser pulses
    • Authors: T. Ring, C. Witte, S. Vasudevan, S. Das, S. T. Ranecky, H. Lee, N. Ladda, A. Senftleben, H. Braun, T. Baumert
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source with well separated and sufficiently resolved mass peaks. The individual control of polarization allows for in situ correction of experimental fluctuations measuring circular dichroism. Our robust optical setup produces reliable and reproducible results and is applicable for dispersion sensitive femtosecond laser pulses. In this contribution, we use 3-methyl-cyclopentanone as a prototype molecule to illustrate the evaluation procedure and the measurement principle.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-10T03:07:32Z
      DOI: 10.1063/5.0036344
       
  • Removing background and estimating a unit height of atomic steps from a
           scanning probe microscopy image using a statistical model
    • Authors: Yuhki Kohsaka
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We present a statistical method to remove background and estimate a unit height of atomic steps of an image obtained using a scanning probe microscope. We adopt a mixture model consisting of multiple statistical distributions to describe an image. This statistical approach provides a comprehensive way to subtract a background surface even in the presence of atomic steps as well as to evaluate terrace heights in a single framework. Moreover, it also enables us to extract further quantitative information by introducing additional prior knowledge about the image. An example of this extension is estimating a unit height of atomic steps together with the terrace heights. We demonstrate the capability of our method for a topographic image of a Cu(111) surface taken using a scanning tunneling microscope. The background subtraction corrects all terraces to be parallel to a horizontal plane, and the precision of the estimated unit height reaches the order of a picometer. An open-source implementation of our method is available on the web.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T02:48:39Z
      DOI: 10.1063/5.0038852
       
  • A robust edge-based template matching algorithm for displacement
           measurement of compliant mechanisms under scanning electron microscope
    • Authors: Yihua Lu, Xianmin Zhang, Shuiquan Pang, Hai Li, Benliang Zhu
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This paper develops a robust edge-based template matching algorithm for displacement measurement of compliant mechanisms under a scanning electron microscope (SEM). The algorithm consists of three steps. First, the Sobel gradient operator and a self-adaptive segment strategy are used to establish the shape model in which the gradient directions of the object’s edge points are calculated. Second, a similarity criterion based on image gradients that is robust to illumination change and image noise is utilized for template matching to obtain the coarse results. The third step is to refine the matching results by using an orientation-guided subpixel interpolation strategy. A series of simulations is conducted, and the results show that the proposed algorithm enjoys great robustness against strong image noise and gray-value fluctuation, as well as small rotations and background interferences, and thus is suitable for processing SEM images of compliant mechanisms. Finally, the application of the proposed algorithm in the measurement of the spring constant of the flexure hinges with a straight beam form under a SEM is demonstrated.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:37Z
      DOI: 10.1063/5.0023244
       
  • Video-based fractional order identification of diffusion dynamics for the
           analysis of migration rates of polar and nonpolar liquids: Water and oil
           studies
    • Authors: Stefani I. E. Andrade, Roberto K. H. Galvão, Mario C. U. Araujo, Sillas Hadjiloucas
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Diffusion dynamics of water and oil are observed in real-time using video images. Savitzky–Golay derivative filtering ensures accurate localization of the liquid front. System identification demonstrates that a fractional-order model with only two parameters may be used to describe the dynamics of the diffusion process. The method paves the way for video-based cellulose filter paper microfluidics and lateral flow assays, which are low cost and have broad diagnostic applications.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:36Z
      DOI: 10.1063/5.0010988
       
  • Performance demonstration of vacuum microwave components critical for the
           operation of the ITER low-field side reflectometer
    • Authors: C. M. Muscatello, J. P. Anderson, R. L. Boivin, D. K. Finkenthal, A. Gattuso, G. J. Kramer, M. LeSher, T. J. Mrazkova, G. H. Neilson, W. A. Peebles, T. L. Rhodes, J. T. Robinson, H. Torreblanca, K. Zeller, L. Zeng, A. Zolfaghari
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Final design studies in preparation for manufacturing have been performed for functional components of the vacuum portion of the ITER Low-Field Side Reflectometer (LFSR). These components consist of an antenna array, electron cyclotron heating (ECH) protection mirrors, phase calibration mirrors, and vacuum windows. Evaluation of these components was conducted at the LFSR test facility and DIII-D. The antenna array consists of six corrugated-waveguide antennas for simultaneous profile, fluctuation, and Doppler measurements. A diffraction grating, incorporated into the plasma-facing miter bend, provides protection of sensitive components from stray ECH at 170 GHz. For in situ phase calibration of the LFSR profile reflectometer, an embossed mirror is incorporated into the adjacent miter bend. Measurements of the radiated beam profile indicate that these components have a small, acceptable effect on mode conversion and beam quality. Baseline transmission characteristics of the dual-disk vacuum window are obtained and are used to guide ongoing developments. Preliminary simulations indicate that a surface-relief structure on the window surfaces can greatly improve transmission. The workability of real-time phase measurements was demonstrated on the DIII-D profile reflectometer. The new automated real-time analysis agrees well with the standard post-processing routine.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:35Z
      DOI: 10.1063/5.0040255
       
  • Comparing plasma conditions in short-pulse-heated foils via fine-structure
           x-ray emission
    • Authors: B. F. Kraus, A. Chien, Lan Gao, K. W. Hill, M. Bitter, P. C. Efthimion, Hui Chen, M. B. Schneider, A. Moreau, R. Hollinger, Shoujun Wang, Huanyu Song, J. J. Rocca
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Fine-structure x-ray spectra have been measured from foils with embedded tracer layers at two laser facilities. A suite of layered foils with thin Ti tracers under varied tamper layers was studied at both the Titan and the ALEPH 400 nm laser facilities, where Ti Heα emission was recorded using a high-resolution Bragg crystal spectrometer. Several indicators of plasma parameters are examined in the spectra, including temperature- and density-dependent line ratios and line broadening from Stark and opacity effects. Spectra indicate that (1) the plasma density at ALEPH is significantly higher than at Titan and (2) the electron temperature is high for near-surface layers at both facilities but drops more quickly with depth at ALEPH. These inferences of plasma conditions are consistent with differing levels of temporal contrast at each laser facility.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:35Z
      DOI: 10.1063/5.0043524
       
  • A symmetric multi-rod tunable microwave cavity for a microwave cavity dark
           matter axion search
    • Authors: Maria Simanovskaia, Alex Droster, Heather Jackson, Isabella Urdinaran, Karl van Bibber
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The microwave cavity technique is currently the most sensitive way of looking for dark matter axions in the 0.1 GHz–10 GHz range, corresponding to masses of 0.41 µeV–41 µeV. A particular challenge for frequencies greater than 5 GHz is designing a cavity with a large volume that contains a resonant mode that shows high coupling to dark matter axions, a high quality factor, is broadly tunable, and is free from intruder modes. For the Haloscope at Yale Sensitive to Axion Cold dark matter, we have designed and constructed an optimized high frequency cavity with a tuning mechanism that preserves a high degree of rotational symmetry, critical to maximizing its figure of merit. This cavity covers an important frequency range according to recent theoretical estimates for the axion mass, 5.5 GHz–7.4 GHz, and the design appears extendable to higher frequencies as well. This paper will discuss key design and construction details of the cavity, present a summary of the design evolution, and alert practitioners of potentially unfruitful avenues for future work.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:34Z
      DOI: 10.1063/5.0016125
       
  • Simultaneous 3D surface profile and pressure measurement using phase-shift
           profilometry and pressure-sensitive paint
    • Authors: Yongzeng Li, Zhe Dong, Lei Liang, Yingzheng Liu, Di Peng
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A simultaneous three-dimensional (3D) surface profile and pressure measurement method that integrates phase-shift profilometry and pressure-sensitive paint (PSP2) is proposed. The advantages of this novel technique over previous 3D pressure-sensitive paint (3D-PSP) techniques include a simplified system with low cost, no interference with PSP coatings, high spatial resolution, and high accuracy. A modified digital light-processing (DLP) projector-structured light generator is used to encode ultraviolet light and generate fringe projection to excite the pressure-sensitive paint. The 3D profile is reconstructed using four phase-shifting emission images. Meanwhile, the surface intensity ratio distribution is obtained. The PSP2 method is applied to a nitrogen jet impingement experiment onto a spherical model. The intensity ratio results obtained using the PSP2 method differ little from the conventional PSP results obtained using uniform excitation. The phase distortion due to the emission intensity fluctuation leads to errors in surface profile measurement, and the fringe projection with high contrast improves surface profile measurement accuracy. In most of the final results, the average total errors between the reconstructed 3D surface and the CAD geometry are less than 0.1 mm.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:34Z
      DOI: 10.1063/5.0031036
       
  • Design of multilayer-based diagnostics for measurement of high energy x
           rays and gamma rays
    • Authors: C. Burcklen, J. von der Linden, A. Do, B. Kozioziemski, M.-A. Descalle, H. Chen
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We investigate several possible multilayer-based optic designs for future hard x-ray and gamma ray diagnostics, including the detection and measurement of the positron annihilation radiation at 511 keV. The focus is set on increasing the photon efficiency and signal-to-noise ratio, compared to a previous multilayer-based system that was successfully employed to measure spectra in the 55 keV–100 keV range. Several possible designs using multilayer coatings are discussed, including mirror-based optics and multilayer Laue lenses.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-09T01:59:33Z
      DOI: 10.1063/5.0043539
       
  • A 1D Lyman-alpha profile camera for plasma edge neutral studies on the
           DIII-D tokamak
    • Authors: A. M. Rosenthal, J. W. Hughes, A. Bortolon, F. M. Laggner, T. M. Wilks, R. Vieira, R. Leccacorvi, E. Marmar, A. Nagy, C. Freeman, D. Mauzey
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A one dimensional, absolutely calibrated pinhole camera system was installed on the DIII-D tokamak to measure edge Lyman-alpha (Ly-α) emission from hydrogen isotopes, which can be used to infer neutral density and ionization rate profiles. The system is composed of two cameras, each providing a toroidal fan of 20 lines of sight, viewing the plasma edge on the inboard and outboard side of DIII-D. The cameras’ views lie in a horizontal plane 77 cm below the midplane. At its tangency radius, each channel provides a radial resolution of ∼2 cm full width at half maximum (FWHM) with a total coverage of 22 cm. Each camera consists of a rectangular pinhole, Ly-α reflective mirror, narrow-band Ly-α transmission filter, and a 20 channel AXUV photodetector. The combined mirror and transmission filter have a FWHM of 5 nm, centered near the Ly-α wavelength of 121.6 nm and is capable of rejecting significant, parasitic carbon-III (C-III) emission from intrinsic plasma impurities. To provide a high spatial resolution measurement in a compact footprint, the camera utilizes advanced engineering and manufacturing techniques including 3D printing, high stability mirror mounts, and a novel alignment procedure. Absolutely calibrated, spatially resolved Ly-α brightness measurements utilize a bright, isolated line with low parasitic surface reflections and enable quantitative comparison to modeling to study divertor neutral leakage, main chamber fueling, and radial particle transport.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-08T02:18:37Z
      DOI: 10.1063/5.0024115
       
  • A temperature-controlled electric field sample environment for small-angle
           neutron scattering experiments
    • Authors: Dominic W. Hayward, Germinal Magro, Anja Hörmann, Sylvain Prévost, Ralf Schweins, Robert M. Richardson, Michael Gradzielski
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A new sample environment is introduced for the study of soft matter samples in electric fields using small-angle neutron scattering instruments. The sample environment is temperature controlled and features external electrodes, allowing standard quartz cuvettes to be used and conducting samples or samples containing ions to be investigated without the risk of electrochemical reactions occurring at the electrodes. For standard 12.5 mm quartz cuvettes, the maximum applied field is 8 kV/cm, and the applied field may be static or alternating (up to 10 kHz for 8 kV/cm and up to 60 kHz for 4 kV/cm). The electric fields within the sample are calculated and simulated under a number of different conditions, and the capabilities of the setup are demonstrated using a variety of liquid crystalline samples. Measurements were performed as a function of temperature and time spent in the electric field. Finally, the advantages, drawbacks, and potential optimization of the sample environment are discussed with reference to applications in the fields of complex soft matter, biology, and electrorheology.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-08T02:18:36Z
      DOI: 10.1063/5.0040675
       
  • Absolute calibration of the Lyman-α measurement apparatus at DIII-D
    • Authors: F. M. Laggner, A. Bortolon, A. M. Rosenthal, T. M. Wilks, J. W. Hughes, C. Freeman, T. Golfinopoulos, A. Nagy, D. Mauzey, M. W. Shafer
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The LLAMA (Lyman-Alpha Measurement Apparatus) diagnostic was recently installed on the DIII-D tokamak [Rosenthal et al., Rev. Sci. Instrum. (submitted) (2020)]. LLAMA is a pinhole camera system with a narrow band Bragg mirror, a bandpass interference filter, and an absolute extreme ultraviolet photodiode detector array, which measures the Ly-α brightness in the toroidal direction on the inboard, high field side (HFS) and outboard, low field side (LFS). This contribution presents a setup and a procedure for an absolute calibration near the Ly-α line at 121.6 nm. The LLAMA in-vacuum components are designed as a compact, transferable setup that can be mounted in an ex situ vacuum enclosure that is equipped with an absolutely calibrated Ly-α source. The spectral purity and stability of the Ly-α source are characterized using a vacuum ultraviolet spectrometer, while the Ly-α source brightness is measured by a NIST-calibrated photodiode. The non-uniform nature of the Ly-α source emission was overcome by performing a calibration procedure that scans the Ly-α source position and employs a numerical optimization to determine the emission pattern. Nominal and measured calibration factors are determined and compared, showing agreement within their uncertainties. A first conversion of the measured signal obtained from DIII-D indicates that the Ly-α brightness on the HFS and LFS is on the order of 1020 Ph sr−1 m−2 s−1. The established calibration setup and procedure will be regularly used to re-calibrate the LLAMA during DIII-D vents to monitor possible degradation of optical components and detectors.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-08T02:18:34Z
      DOI: 10.1063/5.0038134
       
  • An imaging refractometer for density fluctuation measurements in high
           energy density plasmas
    • Authors: J. D. Hare, G. C. Burdiak, S. Merlini, J. P. Chittenden, T. Clayson, A. J. Crilly, J. W. D. Halliday, D. R. Russell, R. A. Smith, N. Stuart, L. G. Suttle, S. V. Lebedev
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We report on a recently developed laser-probing diagnostic, which allows direct measurements of ray-deflection angles in one axis while retaining imaging capabilities in the other axis. This allows us to measure the spectrum of angular deflections from a laser beam, which passes through a turbulent high-energy-density plasma. This spectrum contains information about the density fluctuations within the plasma, which deflect the probing laser over a range of angles. We create synthetic diagnostics using ray-tracing to compare this new diagnostic with standard shadowgraphy and schlieren imaging approaches, which demonstrates the enhanced sensitivity of this new diagnostic over standard techniques. We present experimental data from turbulence behind a reverse shock in a plasma and demonstrate that this technique can measure angular deflections between 0.06 and 34 mrad, corresponding to a dynamic range of over 500.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-08T02:18:33Z
      DOI: 10.1063/5.0040919
       
  • Development of a forward model for Bayesian analysis of a single crystal
           dispersion interferometer
    • Authors: Jae-seok Lee, Dong-Geun Lee, K. C. Lee, J.-W. Juhn, Y.-c. Ghim
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The Single Crystal Dispersion Interferometer (SCDI) is a newly developed dispersion interferometer (DI) system installed on KSTAR and has obtained the first data successfully in January 2020. Unlike conventional heterodyne DI systems, which use two nonlinear crystals, only one nonlinear crystal is used to eliminate the difficulty in overlapping the first and second harmonic beams, aligning and focusing the beams to a small aperture of the second nonlinear crystal, and resolving a problem of significant efforts to maintain the beam alignment to the second nonlinear crystal after a long beam transmission. The second nonlinear crystal is replaced by a frequency doubler, a simple electronic component. To infer a line integrated electron density with its associated uncertainty consistent with the measured data, we develop a forward model of the KSTAR SCDI that can be used as a likelihood within a Bayesian-based data analysis routine. The forward model consists of two main parts, which are an optical system and an electronics system, and it takes into account noises by modeling the mechanical vibrations and the electronic noises as Gaussian distributions, while the photon noise is modeled with a Poisson distribution. The developed forward model can be used for designing and improving the SCDI system.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-08T02:18:31Z
      DOI: 10.1063/5.0043632
       
  • Development of a weighted sum estimate of the total radiated power from
           large helical device plasma
    • Authors: P. L. van de Giessen, G. Kawamura, S. Borling, K. Mukai, B. J. Peterson
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Diagnosing the amount of radiated power is an important research goal for fusion devices. This research aims at better understanding and diagnosing the radiated power from the Large Helical Device (LHD). The current radiated power estimate in the LHD is based on one wide-angle resistive bolometer. Because the estimate stems from one bolometer location toroidally and has a wide-angle poloidal view, this estimate does not take into account toroidal and poloidal radiation asymmetries that are observed in the LHD in discharges with gas puffing. This research develops a method based on the EMC3-Eirene model to calculate the set of coefficients for a weighted-sum method of estimating the radiated power. This study calculates these coefficients by using a least-squares method to solve for a coefficient set, using a variety of simulated cases generated by the EMC3-Eirene model, combined with corresponding geometric radiated power density considerations. If this set of coefficients is multiplied by the detector signal of each bolometer and summed up, this gives a total radiated power estimate. This new estimate takes into account toroidal and poloidal asymmetries by using the bolometer channels viewing different toroidal and poloidal locations, thereby reducing the estimation error and providing information about toroidal asymmetries.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:17Z
      DOI: 10.1063/5.0027302
       
  • Higher magnetic-field generation by a mass-loaded single-turn coil
    • Authors: M. Gen, A. Ikeda, S. Kawachi, T. Shitaokoshi, Y. H. Matsuda, Y. Kohama, T. Nomura
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Single-turn coil (STC) technique is a convenient way to generate ultrahigh magnetic fields of more than 100 T. During the field generation, the STC explosively destructs outward due to the Maxwell stress and Joule heating. Unfortunately, the STC does not work at its full potential because it has already expanded when the maximum magnetic field is reached. Here, we propose an easy way to delay the expansion and increase the maximum field by using a mass-loaded STC. By loading clay on the STC, the field profile drastically changes, and the maximum field increases by 4%. This method offers access to higher magnetic fields for physical property measurements.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:16Z
      DOI: 10.1063/5.0038732
       
  • DANTE as a primary temperature diagnostic for the NIF iron opacity
           campaign
    • Authors: Y. P. Opachich, E. S. Dodd, R. F. Heeter, C. D. Harris, H. M. Johns, J. L. Kline, N. S. Krasheninnikova, M. J. May, A. S. Moore, M. S. Rubery, M. B. Schneider, T. J. Urbatsch, K. Widmann, T. S. Perry
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The Opacity Platform on the National Ignition Facility (NIF) has been developed to measure iron opacities at varying densities and temperatures relevant to the solar interior and to verify recent experimental results obtained at the Sandia Z-machine, that diverge from theory. The first set of NIF experiments collected iron opacity data at ∼150 eV to 160 eV and an electron density of ∼7 × 1021 cm−3, with a goal to study temperatures up to ∼210 eV, with electron densities of up to ∼3 × 1022 cm−3. Among several techniques used to infer the temperature of the heated Fe sample, the absolutely calibrated DANTE-2 filtered diode array routinely provides measurements of the hohlraum conditions near the sample. However, the DANTE-2 temperatures are consistently low compared to pre-shot LASNEX simulations for a range of laser drive energies. We have re-evaluated the estimated uncertainty in the reported DANTE-2 temperatures and also the error generated by varying channel participation in the data analysis. An uncertainty of ±5% or better can be achieved with appropriate spectral coverage, channel participation, and metrology of the viewing slot.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:14Z
      DOI: 10.1063/5.0040972
       
  • Dispersion calibration for the National Ignition Facility
           electron–positron–proton spectrometers for intense laser matter
           interactions
    • Authors: Jens von der Linden, José Ramos-Méndez, Bruce Faddegon, Devan Massin, Gennady Fiksel, Joe P. Holder, Louise Willingale, Jonathan Peebles, Matthew R. Edwards, Hui Chen
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Electron–positron pairs, produced in intense laser–solid interactions, are diagnosed using magnetic spectrometers with image plates, such as the National Ignition Facility Electron–Positron–Proton Spectrometers (EPPSs). Although modeling can help infer the quantitative value, the accuracy of the models needs to be verified to ensure measurement quality. The dispersion of low-energy electrons and positrons may be affected by fringe magnetic fields near the entrance of the EPPS. We have calibrated the EPPS with six electron beams from a Siemens Oncor linear accelerator (linac) ranging in energy from 2.7 MeV to 15.2 MeV as they enter the spectrometer. A Geant4 traveling-wave optical parametric amplifier of superfluorescence Monte Carlo simulation was set up to match depth dose curves and lateral profiles measured in water at 100 cm source–surface distance. An accurate relationship was established between the bending magnet current setting and the energy of the electron beam at the exit window. The simulations and measurements were used to determine the energy distributions of the six electron beams at the EPPS slit. Analysis of the scanned image plates together with the determined energy distribution arriving in the spectrometer provides improved dispersion curves for the EPPS.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:12Z
      DOI: 10.1063/5.0040624
       
  • Modeling and control of transverse coupled bunch mode levels in Indus-2
           using artificial neural network
    • Authors: Surendra Yadav, T. A. Puntambekar, P. V. Varde
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Transverse coupled bunch instability (TCBI) is a major concern at high beam current operations at all synchrotron light sources. Techniques for the mitigation of TCBI include higher order mode tuning of RF cavities, optimization of vacuum chamber designs, increasing the damping rate of beam oscillations, optimization of betatron tune values, and multi-bunch feedback systems. Due to uncertainties, time-variation, and disturbances, the dynamic behavior of accelerators requires further tuning of beam parameters beyond theory-based set points for minimizing the transverse coupled bunch mode (TCBM) instability. In this work, an artificial neural network (ANN) based system is developed to minimize average TCBM levels in the Indus-2 synchrotron light source at the Raja Ramanna Centre for Advanced Technology in Indore, India. The ANN is trained based on various TCBM measurements collected at the Indus-2 for various values of betatron tune and chromaticity in order to learn how to map beam measurements directly to parameters such as optimal betatron tunes and chromaticity values that are sent to a beam feedback control system. The ANN takes as input real-time beam data and is coupled to a feedback controller, thereby creating an adaptive feedback that is able to adjust in real time to variation of the accelerator and beam. We provide a detailed overview of our approach as well as experimental results in which the ANN-guided feedback approach increases the operational beam current of Indus-2 from a limit of ∼170 mA up to ∼230 mA within ∼21 min. We believe that this general method can be useful for a wide range of synchrotron sources operating at high bunch currents.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:11Z
      DOI: 10.1063/5.0016339
       
  • A digital holography ex situ measurement characterization of
           plasma-exposed surface erosion from an electrothermal arc source
    • Authors: C. D. Smith, T. M. Biewer, T. Gebhart, J. Echols, C. E. Thomas
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Digital holography has been proposed to fulfill a need for an imaging diagnostic capable of in situ monitoring of surface erosion caused by plasma–material interaction in nuclear fusion devices. A digital holography diagnostic for 3D surface erosion measurement has been developed at Oak Ridge National Laboratory with the goal of deployment on a plasma device. A proof-of-concept in situ demonstration is planned which would involve measurement of plasma erosion on targets exposed to an electrothermal arc source. This work presents the results of an ex situ characterization of the capability and limitations of holographic imaging of targets exposed to the arc source. Targets were designed to provide a fiducial for comparison of deformed and unaffected areas. The results indicated that the average net erosion was ∼150 nm/plasma exposure, which is expected to be within the diagnostic’s measurement capacity. Surface roughness averages determined by holographic image analysis showed good agreement with measurements taken with a profilometer. The limit of the holography diagnostic’s x–y spatial resolution was characterized by comparison with scanning electron microscope imaging.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-05T12:45:10Z
      DOI: 10.1063/5.0041279
       
  • High-power solid-state amplifier for superconducting radio frequency
           cavity test facility
    • Authors: Akhilesh Jain, Deepak Kumar Sharma, Alok Kumar Gupta, Kriti Pathak, M. R. Lad
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A horizontal test facility is set up at the Raja Ramanna Centre for Advanced Technology to test the superconducting radio frequency dressed cavities. Along with the cryomodule, control instrumentation, and the power coupler, this facility incorporates a high-power solid-state amplifier for establishing the desired cavity voltage gradient during the testing. This article describes the design, construction, rigorous testing, and measured results of this high-power solid-state radio frequency amplifier and its constituent components. Its maximum output power is 36 kW (average) at the operating frequency of 650 MHz. Its main features are its modular and scalable design with in-house developed constituent components. These components include 500 W, 20 dB gain modules, novel two-tier radial dividers, combiners, power sensors, and aperture-coupled directional couplers. Their excellent reprise performance for the multiple quantities confirms the design methodology presented here. The measured wall plug efficiency of this 36 kW amplifier is 43.6%, and its power gain is 86 dB. The designed radial combiner is highly efficient (power-combining efficiency of 98.4%), and the directional coupler exhibits a very low loss (insertion loss of 0.05 dB).
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:54:29Z
      DOI: 10.1063/5.0030896
       
  • Dual-mode auto-calibrating resistance thermometer: A novel approach with
           Johnson noise thermometry
    • Authors: D. Drung, C. Krause
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A dual-mode auto-calibrating resistance thermometer (DART) is presented. The novel DART concept combines in one instrument the fast and accurate resistance thermometry with the primary method of Johnson noise thermometry. Unlike previous approaches, the new thermometer measures the spectral density of the thermal noise in the sensing resistor directly in a sequential measurement procedure without using correlation techniques. A sophisticated data analysis corrects the thermometer output for both the parasitic effects of the sensor wiring and the amplifier current noise. The instrument features a highly linear low-noise DC coupled amplifier with negative feedback as well as an accurate voltage reference and reference resistor to improve the gain stability over time and ambient temperature. Therefore, the system needs only infrequent calibrations with electrical quantum standards and can be operated over long intervals and a wide temperature range without recalibration. A first prototype is designed for the industrially relevant temperature range of the IEC 60751 (−200 °C to +850 °C); a later extension of the measurement range is being considered. A proof-of-principle measurement with a calibrated Pt100 sensor at room temperature yielded an uncertainty of about 100 µK/K. The final device is expected to reach uncertainties of below 10 µK/K, suitable for accurate measurements of the difference between thermodynamic temperatures and temperatures traceable to the International Temperature Scale of 1990 (ITS-90).
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:54:29Z
      DOI: 10.1063/5.0035673
       
  • A stellar/inertial integrated navigation method based on the observation
           of the star centroid prediction error
    • Authors: Yuanman Ni, Wenfeng Tan, Dongkai Dai, Xingshu Wang, Shiqiao Qin
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The stellar/inertial integrated navigation system, which combines the inertial navigation system (INS) and the star tracker, can restrain the accumulated INS errors. In the traditional loosely coupled stellar/inertial integration method, the star tracker needs to observe more than two navigation stars on an image for attitude determination and to use the attitude information as the observation to estimate the systematic errors of the INS. However, under strong background radiation conditions, the star number in the field of view (FOV) usually drops below 3; thus, the loosely coupled method fails to work. To overcome this difficulty, an improved tightly coupled stellar/inertial integration method based on the observation of the star centroid prediction error (SCPE) is proposed in this paper. It calculates the difference between the extracted star centroid and the predicted star centroid, namely, the SCPE, as the observation and then estimates the INS errors with a Kalman filter. Numerical simulations and ground experiments are conducted to validate the feasibility of the tightly coupled method. It is proved that the proposed method, which makes full use of all star observation information, can improve the navigation accuracy compared with the loosely coupled method and is more robust when there are not enough stars in the FOV.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:54:28Z
      DOI: 10.1063/5.0027530
       
  • A time-resolved, in-chamber x-ray pinhole imager for Z
    • Authors: Timothy J. Webb, David Ampleford, Christopher R. Ball, Matthew R. Gomez, Patrick W. Lake, Andrew Maurer, Radu Presura
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We have commissioned a new time-resolved, x-ray imaging diagnostic for the Z facility. The primary intended application is for diagnosing the stagnation behavior of Magnetized Liner Inertial Fusion (MagLIF) and similar targets. We have a variety of imaging systems at Z, both time-integrated and time-resolved, that provide valuable x-ray imaging information, but no system at Z up to this time provides a combined high-resolution imaging with multi-frame time resolution; this new diagnostic, called TRICXI for Time Resolved In-Chamber X-ray Imager, is meant to provide time-resolved spatial imaging with high resolution. The multi-frame camera consists of a microchannel plate camera. A key component to achieving the design goals is to place the instrument inside the Z vacuum chamber within 2 m of the load, which necessitates a considerable amount of x-ray shielding as well as a specially designed, independent vacuum system. A demonstration of the imaging capability for a series of MagLIF shots is presented. Predictions are given for resolution and relative image irradiance to guide experimenters in choosing the desired configuration for their experiments.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:16Z
      DOI: 10.1063/5.0040706
       
  • Application of motional Stark effect in situ background correction to a
           superconducting tokamak
    • Authors: Jinseok Ko, Steve Scott, Fred Levinton, Matthew Galante, Steve Sabbagh, Sang-hee Hahn, YoungMu Jeon
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A polychrometer-type motional Stark effect (MSE) diagnostic technique, originally developed for the Alcator C-Mod tokamak, has been extended and applied to the Korea Superconducting Advanced Tokamak Research (KSTAR) device, the long-pulse superconducting tokamak, for the first time. It demonstrates a successful in situ subtraction of the polarized reflections off the vacuum vessel wall, sometimes up to half the total signal in some sightlines. To avoid the secondary neutral beam emission that may contaminate conventional beam-into-gas calibrations, a new approach, where the beam-into-gas measurements are made at various torus pressures with fixed vacuum fields, has been devised, which is possible with the stable superconducting coil systems of KSTAR. The validity of this new calibration scheme has been checked via plasma jog experiments. The experimental evidence of the polarized background light and the necessity of its correction in the MSE measurements made in KSTAR are presented as well.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:15Z
      DOI: 10.1063/5.0040823
       
  • Interlaboratory validation of a hanging pendulum thrust balance for
           electric propulsion testing
    • Authors: A. Schwertheim, E. Rosati Azevedo, G. Liu, E. Bosch Borràs, L. Bianchi, A. Knoll
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A hanging pendulum thrust balance has been developed by Imperial College London in collaboration with the European Space Agency (ESA) to characterize a wide range of static fire electric propulsion and chemical micro-propulsion devices with thrust in the range of 1 mN to 1 N. The thrusters under investigation are mounted on a pendulum platform, which is suspended from the support structure using stainless steel flexures. The displacement of the platform is measured using an optical laser triangulation sensor. Thermal stability is ensured by a closed loop self-compensating heating system. The traceability and stability of the calibration are ensured using two separate calibration subsystems: a voice coil actuator and a servomotor pulley system. Two nearly identical thrust balances have been constructed, with one being tested in the Imperial Plasma Propulsion Laboratory and the other in the ESA Propulsion Laboratory. Both balances show a high degree of linearity in the range of 0.5 mN–100 mN. Both instruments have demonstrated a stable calibration over several days, with an estimated standard deviation on thrust measurements better than 0.27 mN for low thrust measurements. The same electric propulsion test article was used during both tests: a Quad Confinement Thruster (QCT) variant called QCT Phoenix. This thruster differed from previous QCT designs by having a newly optimized magnetic topology. The device produced thrust up to 2.21 ± 0.22 mN with a maximum specific impulse of 274 ± 41 s for an anode power range of 50 W–115 W.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:14Z
      DOI: 10.1063/5.0037100
       
  • A new setup for low-temperature gas-phase ion fluorescence spectroscopy
    • Authors: Christina Kjær, Jeppe Langeland, Thomas Toft Lindkvist, Emma Rostal Sørensen, Mark H. Stockett, Henrik G. Kjaergaard, Steen Brøndsted Nielsen
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Here, we present a new instrument named LUNA2 (LUminescence iNstrument in Aarhus 2), which is purpose-built to measure dispersed fluorescence spectra of gaseous ions produced by electrospray ionization and cooled to low temperatures (
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:13Z
      DOI: 10.1063/5.0038880
       
  • Broadband femtosecond spectroscopic ellipsometry
    • Authors: Steffen Richter, Mateusz Rebarz, Oliver Herrfurth, Shirly Espinoza, Rüdiger Schmidt-Grund, Jakob Andreasson
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We present a setup for time-resolved spectroscopic ellipsometry in a pump–probe scheme using femtosecond laser pulses. As a probe, the system deploys supercontinuum white light pulses that are delayed with respect to single-wavelength pump pulses. A polarizer–sample–compensator–analyzer configuration allows ellipsometric measurements by scanning the compensator azimuthal angle. The transient ellipsometric parameters are obtained from a series of reflectance-difference spectra that are measured for various pump–probe delays and polarization (compensator) settings. The setup is capable of performing time-resolved spectroscopic ellipsometry from the near-infrared through the visible to the near-ultraviolet spectral range at 1.3 eV–3.6 eV. The temporal resolution is on the order of 100 fs within a delay range of more than 5 ns. We analyze and discuss critical aspects such as fluctuations of the probe pulses and imperfections of the polarization optics and present strategies deployed for circumventing related issues.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:09Z
      DOI: 10.1063/5.0027219
       
  • Improvement in multipass Thomson scattering system comprising laser
           amplification system developed in GAMMA 10/PDX
    • Authors: M. Yoshikawa, T. Mouri, H. Nakanishi, J. Kohagura, Y. Shima, M. Sakamoto, Y. Nakashima, N. Ezumi, R. Minami, I. Yamada, R. Yasuhara, H. Funaba, T. Minami, N. Kenmochi
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The multipass Thomson scattering (MPTS) technique is one of the most useful methods for measuring low-electron-density plasmas. The MPTS system increases Thomson scattering (TS) signal intensities by integrating all multipass (MP) signals and improving the TS time resolution by analyzing each pass signal. The fully coaxial MPTS system developed in GAMMA 10/potential-control and diverter–simulator experiments has a polarization-based configuration with image-relaying optics. The MPTS system can enhance Thomson scattered signals for improving the measurement accuracy and megahertz-order time resolution. In this study, we develop a new MPTS system comprising a laser amplification system to obtain continuous MP signals. The laser amplification system can improve degraded laser power and return an amplified laser to the MP system. We obtain continuous MP signals from the laser amplification system by improving the laser beam profile adjuster in gas scattering experiments. Moreover, we demonstrate that more MP signals and stronger amplified MP signals can be achieved via multiple laser injections to the laser amplification system in the developed MP system comprising a laser amplification system.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:08Z
      DOI: 10.1063/5.0040461
       
  • Top-level physics requirements and simulated performance of the MRSt on
           the National Ignition Facility
    • Authors: J. H. Kunimune, J. A. Frenje, G. P. A. Berg, C. A. Trosseille, R. C. Nora, C. S. Waltz, A. S. Moore, J. D. Kilkenny, A. J. Mackinnon
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The time-resolving Magnetic Recoil Spectrometer (MRSt) for the National Ignition Facility (NIF) has been identified by the US National Diagnostic Working Group as one of the transformational diagnostics that will reshape the way inertial confinement fusion (ICF) implosions are diagnosed. The MRSt will measure the time-resolved neutron spectrum of an implosion, from which the time-resolved ion temperature, areal density, and yield will be inferred. Top-level physics requirements for the MRSt were determined based on simulations of numerous ICF implosions with varying degrees of alpha heating, P2 asymmetry, and mix. Synthetic MRSt data were subsequently generated for different configurations using Monte–Carlo methods to determine its performance in relation to the requirements. The system was found to meet most requirements at current neutron yields at the NIF. This work was supported by the DOE and LLNL.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-04T01:16:06Z
      DOI: 10.1063/5.0040745
       
  • Fast production of microwave component prototypes by additive
           manufacturing and copper coating
    • Authors: S. B. Korsholm, F. Leipold, R. B. Madsen, H. Gutierrez, T. Jensen, M. Jessen, A. W. Larsen, J. Rasmussen, M. Salewski
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We present a novel method for efficient production of prototypes of microwave components by fused depositing modeling, also known as 3D plastic printing, and vapor deposition coating of a 1 μm copper layer. We demonstrate that the properties of the components follow the predicted performance for low power microwave propagation. The production method offers new opportunities for cheap and efficient production of mock-ups and prototypes of advanced-geometry components for tests with low-power microwaves.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:11Z
      DOI: 10.1063/5.0043816
       
  • Incoherent Thomson scattering system for PHAse space MApping (PHASMA)
           experiment
    • Authors: Peiyun Shi, Prabhakar Srivastav, Cuyler Beatty, Ripudaman Singh Nirwan, Earl E. Scime
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A new incoherent Thomson scattering system measures the evolution of electron velocity distribution functions perpendicular and parallel to the ambient magnetic field during kinking of a single flux rope and merging of two flux ropes through magnetic reconnection. The Thomson scattering system provides sub-millimeter spatial resolution, sufficient to diagnose the several millimeters sized magnetic reconnection electron diffusion region in the PHAse Space MAppgin experiment. Due to the relatively modest plasma density ∼1019 m−3 and electron temperature ∼1 eV, stray light suppression is critical for these measurements. Two volume Bragg gratings are used in series as a notch filter with a spectral bandwidth 47% is used as the detector in a 1.3 m spectrometer. Preliminary results of gun plasma electron temperature will be reported and compared with measurements obtained from a triple Langmuir probe.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:10Z
      DOI: 10.1063/5.0040606
       
  • Frequency shift algorithm: Application to a frequency-domain multiplexing
           readout of x-ray transition-edge sensor microcalorimeters
    • Authors: D. Vaccaro, H. Akamatsu, J. van der Kuur, P. van der Hulst, A. C. T. Nieuwenhuizen, P. van Winden, L. Gottardi, R. den Hartog, M. P. Bruijn, M. D’Andrea, J. R. Gao, J. W. A. den Herder, R. W. M. Hoogeveen, B. Jackson, A. J. van der Linden, K. Nagayoshi, K. Ravensberg, M. L. Ridder, E. Taralli, M. de Wit
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:10Z
      DOI: 10.1063/5.0032011
       
  • A supersonic laser ablation beam source with narrow velocity spreads
    • Authors: P. Aggarwal, H. L. Bethlem, A. Boeschoten, A. Borschevsky, K. Esajas, Y. Hao, S. Hoekstra, K. Jungmann, V. R. Marshall, T. B. Meijknecht, M. C. Mooij, R. G. E. Timmermans, A. Touwen, W. Ubachs, L. Willmann, Y. Yin, A. Zapara
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A supersonic beam source for SrF and BaF molecules is constructed by combining the expansion of carrier gas (a mixture of 2% SF6 and 98% argon) from an Even–Lavie valve with laser ablation of a barium/strontium metal target at a repetition rate of 10 Hz. Molecular beams with a narrow translational velocity spread are produced at relative values of Δv/v = 0.053(11) and 0.054(9) for SrF and BaF, respectively. The relative velocity spread of the beams produced in our source is lower in comparison with the results from other metal fluoride beams produced in supersonic laser ablation sources. The rotational temperature of BaF is measured to be 3.5 K. The source produces 6 × 108 and 107 molecules per steradian per pulse in the X2Σ+ (ν = 0, N = 1) state of BaF and SrF molecules, respectively, a state amenable to Stark deceleration and laser cooling.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:07Z
      DOI: 10.1063/5.0035568
       
  • Impact of the gas dynamics on the cluster flux in a magnetron
           cluster-source: Influence of the chamber shape and gas-inlet position
    • Authors: Giuseppe Sanzone, Jinlong Yin, Kevin Cooke, Hailin Sun, Peter Lievens
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Although producing clusters by physical methods offers many benefits, low deposition rates have prevented cluster-beam deposition techniques from being adopted more widely. The influence of the gas aerodynamics inside the condensation chamber of a magnetron cluster-source on the cluster throughput is reported, leading to an improved understanding of the influence of gas aerodynamics on cluster transport. In the first part of this paper, the influence of the carrier gas’s inlet position on the cluster flux is studied. In particular, two inlet configurations were investigated, i.e., from the rear of the chamber and from within the magnetron sputtering source. It was found experimentally that the latter configuration can lead to an increased cluster flux, under the same conditions of gas pressure and power applied to the magnetron. This behavior is explained with the help of simulations. In the second part of this paper, the gas dynamics behavior inside four chamber shapes, namely, two cylindrical shapes with different cross-sectional diameters and two conical shapes with different apex angles, was simulated. The modeling showed that the fraction of clusters successfully leaving the aggregation zone can be increased by up to eight times from the worst to the best performing chamber geometries studied. Finally, the cluster throughput was determined experimentally using a quartz microbalance in two of the four chamber designs. It was found that the cluster flux increased up to one order of magnitude, reaching ∼20 mg/h for a condensation chamber with a smaller cross section and a conical exit.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:05Z
      DOI: 10.1063/5.0028854
       
  • Fast modulating electron cyclotron emission (FMECE) diagnostic for
           tokamaks
    • Authors: Saeid Houshmandyar, Ruifeng Xie, Max E. Austin, William L. Rowan, Hailin Zhao
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Utilizing variable-frequency channels, e.g., yttrium iron garnet (YIG) bandpass filters, in the intermediate frequency (IF) section of an electron cyclotron emission (ECE) radiometer facilitates flexibility in the volume viewed by the ECE channels as well as high resolution electron temperature and temperature fluctuation measurements in tokamaks. Fast modulating electron cyclotron emission (FMECE), a stand-alone IF section with eight channels, is a novel application of YIG filters for real-time electron temperature gradient and gradient scale length measurements. Key to FMECE is a simultaneous input/output data acquisition unit, as well as a modified type of YIG filters, which is capable of fast switching of their center (set) frequencies with a frequency slew rate of 600 µs/GHz. A new FMECE has been implemented and tested on the DIII-D tokamak, demonstrating its capability in real-time gradient measurements. The data presented here shows that FMECE can identify flattening in the electron temperature profile; the latter can be used as a sensor for real time monitoring and control of plasma instabilities. Implementation and application are planned for the EAST tokamak.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:04Z
      DOI: 10.1063/5.0043761
       
  • The Scattered Light Time-history Diagnostic suite at the National Ignition
           Facility
    • Authors: M. J. Rosenberg, J. E. Hernandez, N. Butler, T. Filkins, R. E. Bahr, R. K. Jungquist, M. Bedzyk, G. Swadling, J. S. Ross, P. Michel, N. Lemos, J. Eichmiller, R. Sommers, P. Nyholm, R. Boni, J. A. Marozas, R. S. Craxton, P. W. McKenty, A. Sharma, P. B. Radha, D. H. Froula, P. Datte, M. Gorman, J. D. Moody, J. M. Heinmiller, J. Fornes, P. Hillyard, S. P. Regan
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The Scattered Light Time-history Diagnostic (SLTD) is being implemented at the National Ignition Facility (NIF) to greatly expand the angular coverage of absolute scattered-light measurements for direct- and indirect-drive inertial confinement fusion (ICF) experiments. The SLTD array will ultimately consist of 15 units mounted at a variety of polar and azimuthal angles on the NIF target chamber, complementing the existing NIF backscatter suite. Each SLTD unit collects and diffuses scattered light onto a set of three optical fibers, which transport the light to filtered photodiodes to measure scattered light in different wavelength bands: stimulated Brillouin scattering (350 nm–352 nm), stimulated Raman scattering (430 nm–760 nm), and ω/2 (695 nm–745 nm). SLTD measures scattered light with a time resolution of ∼1 ns and a signal-to-noise ratio of up to 500. Currently, six units are operational and recording data. Measurements of the angular dependence of scattered light will strongly constrain models of laser energy coupling in ICF experiments and allow for a more robust inference of the total laser energy coupled to implosions.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:02Z
      DOI: 10.1063/5.0040558
       
  • A field programmable gate array based synchronization mechanism of analog
           and digital local oscillators in bandwidth-interleaved data acquisition
           systems
    • Authors: Yu Zhao, Peng Ye, Kuojun Yang, Jie Meng, Maolin Lei
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This paper studies the synchronization between the analog and digital local oscillators (LOs) in bandwidth-interleaved (BI) data acquisition systems (DAQS). It gives a detailed analysis of the random synchronization phase difference between the analog and digital LOs in the BI-DAQS among different acquisition frames. Exploiting the synchrony relation between the analog LO and sampling clock of the BI-DAQS, the synchronization between analog and digital LOs, where the digital LO is generated in the sampling clock domain, in each acquisition frame is realized in the Field Programmable Gate Array (FPGA). A BI-DAQS platform with a 5.5 GHz bandwidth and 20 Gs/s sampling rate is built to validate the proposed synchronization mechanism. Experimental results in the platform show the efficacy of the proposed synchronization mechanism, which consumes only a small amount of the flip-flops and look-up tables in the FPGA without any additional hardware assistance.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:01Z
      DOI: 10.1063/5.0039666
       
  • A procedure and device for determining complex material permittivity using
           the free-space resonance method
    • Authors: Lin Qin, En Li, Yunpeng Zhang, Gaofeng Guo, Liangliang Chen, Minggang Hu, Chengyong Yu, Canping Li
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The essential technologies of the complex permittivity of microwave dielectric materials are systematically designed, and the complex permittivity of materials is tested nondestructively by the free-space resonance method. A testing system was built by using a mobile surveying platform, and the complex dielectric constant of the material in the X band was nondestructively tested by using the algorithm of variable physical cavity length and constant physical cavity length. Focusing on the impact of variable physical cavity length on the test results, the cavity calibration technology is proposed to reduce the influence on the complex dielectric constant test of materials. The free-space resonance method was used to test the complex permittivity of polytetrafluoroethylene, glass steel plate (fiber reinforced plastics), and corundum plate. The results show that the test results of complex permittivity obtained by the two algorithms are consistent, and the error of complex permittivity is less than 5%.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:58:01Z
      DOI: 10.1063/5.0035361
       
  • Characterization of micrometer-size laser beam using a vibrating wire as a
           miniature scanner
    • Authors: S. G. Arutunian, A. V. Margaryan, G. S. Harutyunyan, E. G. Lazareva, A. T. Darpasyan, D. S. Gyulamiryan, M. Chung, D. Kwak
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A new method for profile measurements of small transverse size beams by means of a vibrating wire is presented. A vibrating wire resonator with a new magnetic system was developed and manufactured to ensure that the wire oscillated in a single plane. Presented evidence gives us confidence that the autogenerator creates vibrations at the natural frequency of the wire in a plane of the magnetic system, and these vibrations are sinusoidal. The system for measuring the laser beam reflected from the vibrating wire by means of a fast photodiode was upgraded. The experiments allowed the reconstruction of a fine structure of the focused beam of the semiconductor laser using only a few vibrating wire oscillations. The system presented here would eventually enable the implementation of tomographic measurements of the thin beam profile.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-03T01:57:59Z
      DOI: 10.1063/5.0028666
       
  • A Bitter-type electromagnet for complex atomic trapping and manipulation
    • Authors: J. L. Siegel, D. S. Barker, J. A. Fedchak, J. Scherschligt, S. Eckel
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      We create a pair of symmetric Bitter-type electromagnet assemblies capable of producing multiple field configurations including uniform magnetic fields, spherical quadruple traps, or Ioffe–Pritchard magnetic bottles. Unlike other designs, our coil allows both radial and azimuthal cooling water flows by incorporating an innovative 3D-printed water distribution manifold. Combined with a double-coil geometry, such orthogonal flows permit stacking of non-concentric Bitter coils. We achieve a low thermal resistance of 4.2(1) °C kW−1 and high water flow rate of 10.0(3) l min−1 at a pressure of 190(10) kPa.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T02:51:10Z
      DOI: 10.1063/5.0026812
       
  • High-resolution x-ray radiography with Fresnel zone plates on the
           University of Rochester’s OMEGA Laser Systems
    • Authors: F. J. Marshall, S. T. Ivancic, C. Mileham, P. M. Nilson, J. J. Ruby, C. Stoeckl, B. S. Scheiner, M. J. Schmitt
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Experiments performed at the Laboratory for Laser Energetics with a continuous-wave (cw) x-ray source and on the OMEGA and OMEGA EP Laser Systems [Boehly et al., Opt. Commun. 133, 495 (1997) and Waxer et al., Opt. Photonics News 16, 30 (2005)] have utilized a Fresnel zone plate (FZP) to obtain x-ray images with a spatial resolution as small as ∼1.5 μm. Such FZP images were obtained with a charge-coupled device or a framing camera at energies ranging from 4.5 keV to 6.7 keV using x-ray line emission from both the cw source and high-intensity, laser-beam–illuminated metal foils. In all cases, the resolution test results are determined from patterns and grids backlit by these sources. The resolutions obtained are shown to be due to a combination of the spectral content of the x-ray sources and detector resolution limited by the magnification of the images (14× to 22×). High-speed framing cameras were used to obtain FZP images with frame times as short as ∼30 ps. Double-shell implosions on OMEGA were backlit by laser-irradiated Fe foils, thus obtaining a framing-camera–limited, FZP-image resolution of ∼3 μm–4 μm.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T02:51:09Z
      DOI: 10.1063/5.0034903
       
  • The curling probe: A numerical and experimental study. Application to the
           electron density measurements in an ECR plasma thruster
    • Authors: Federico Boni, Julien Jarrige, Victor Désangles, Tiberiu Minea
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The measurement of electron density is a key issue in understanding and controlling plasma applications. To date, plasma density in electric thrusters has been mainly evaluated with electrostatic techniques, such as the Langmuir probe, which could be quite invasive. In this paper, we propose the application of a microwave resonant probe, the curling probe, to the diagnostic of an electrodeless plasma thruster. The measurable electron density range and the probe accuracy are found to be limited by the probe natural frequency. We present the numerical study and the experimental characterization of three curling probes with different natural frequencies (700, 1400, and 3000 MHz, approximately). First, an analytical equation of the natural frequency as a function of geometrical parameters is drawn from 2D numerical simulations. Then, a procedure based on solid dielectric etalons is proposed for the absolute calibration of the probe. Finally, measurements are performed in the plume of an electron cyclotron resonance plasma thruster. Electron densities from 108 to 1011 cm−3 have been obtained in agreement with hairpin and Langmuir probes results. A wall-embedded probe has enabled measurements inside the thruster source with minimal plasma perturbation. A possible curling probe configuration, embedded in a reactor wall, is proposed as a fully non-invasive diagnostic for plasma sources.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:41Z
      DOI: 10.1063/5.0040175
       
  • Identification of static nonlinearities by sinusoidal excitation with
           variable DC offsets
    • Authors: Tim C. Kranemann, Georg Schmitz
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      When identifying nonlinear systems with input–output measurements, a suitable test signal must be selected. Nonlinear systems are almost always in a cascade with linear systems, i.e., a Wiener–Hammerstein type system cascade. A suitable test signal is preferably less influenced by the linear systems and is therefore sinusoidal, if time-varying signals are required for the measurement principle, e.g., for induction or vibration measurements. Then, a sinusoidal excitation with different DC offsets is a suitable signal to analyze a static nonlinear system in a Wiener–Hammerstein type cascade by measuring the cascade output at higher harmonics of the input frequency in a steady state, e.g., by using sensitive lock-in techniques. To calculate the cascade output given the input signal or to reconstruct the static nonlinear system also given the output signal, the transfer function of the DC offset at the nonlinear system input to the higher harmonics at the nonlinear system output is required. Those transfer functions are calculated here with emphasis on the first harmonic component. The reconstruction of a static nonlinear system is demonstrated in a simple simulation scenario by inverse filtering, i.e., deconvolution, with the derived transfer function. It is pointed out that a commonly made small signal assumption to the test signal is bypassed with the deconvolution method, which can lead to more precise measurements in applications due to a higher signal-to-noise ratio at the cascade output.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:39Z
      DOI: 10.1063/5.0036696
       
  • Resistive-nanoindentation on gold: Experiments and modeling of the
           electrical contact resistance
    • Authors: Fabien Volpi, Morgan Rusinowicz, Solène Comby-Dassonneville, Guillaume Parry, Chaymaa Boujrouf, Muriel Braccini, Didier Pellerin, Marc Verdier
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This paper reports the experimental, analytical, and numerical study of resistive-nanoindentation tests performed on gold samples (bulk and thin film). First, the relevant contributions to electrical contact resistance are discussed and analytically described. A brief comparison of tests performed on gold and on natively oxidized metals highlights the high reproducibility and the voltage-independence of experiments on gold (thanks to its oxide-free surface). Then, the evolution of contact resistance during nanoindentation is fully explained in terms of electronic transport regimes: starting from tunneling, electronic transport is then driven by ballistic conduction before ending with pure diffusive conduction. The corresponding analytical expressions, as well as their validity domains, are determined and compared with experimental data, showing excellent agreement. From there, focus is made on the diffusive regime. Resistive-nanoindentation outputs are fully described by analytical and finite-element modeling. The developed numerical framework allows a better understanding of the main parameters: it first assesses the technique capabilities (validity domains, sensitivity to tip defect, sensitivity to rheology, effect of an oxide layer, and so on), but it also validates the different assumptions made on current line distribution. Finally, it is shown that a simple calibration procedure allows a well-resolved monitoring of the contact area during resistive-nanoindentation performed on samples with complex rheologies (ductile thin film on an elastic substrate). Comparison to analytical and numerical approaches highlights the strength of resistive-nanoindentation for continuous area monitoring.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:38Z
      DOI: 10.1063/5.0032682
       
  • Production of metallic ion beams by electron cyclotron resonance ion
           sources equipped with inductive heating ovens at the Institute of Modern
           Physics
    • Authors: W. Lu, C. Qian, W. H. Zhang, H. Y. Ma, J. D. Ma, Y. C. Feng, L. B. Li, L. X. Li, J. W. Guo, W. Huang, X. Z. Zhang, L. T. Sun, H. W. Zhao
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A high-temperature oven based on the inductive heating technology was developed successfully at the Institute of Modern Physics in 2019. This oven features a durable operation temperature of over 2000 °C inside the tantalum susceptor. By carefully designing the oven structure, the material compatibility issue at high temperature has been successfully solved, which enables the production and routine operation of refractory metal ions with SECRAL-II (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou No. 2). To further apply this type of oven to the room temperature ECR ion sources LECR4 and LECR5 (Lanzhou Electron Cyclotron Resonance ion source No. 4 and 5), a mini-inductive heating oven has been fabricated and tested in 2020. By directly evaporating calcium oxide, some high charge state calcium beams have been produced successfully, such as 52 euA of 40Ca16+, 30 euA of 40Ca17+, and 12 euA of 40Ca18+. The detailed design and testing results will be presented and discussed.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:35Z
      DOI: 10.1063/5.0041671
       
  • Comment on “Requirements and sensitivity analysis for temporally- and
           spatially-resolved thermometry using neutron resonance spectroscopy”
           [Rev. Sci. Instrum. 90, 094901 (2019)]
    • Authors: Damian C. Swift, James M. McNaney
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.

      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:33Z
      DOI: 10.1063/1.5133415
       
  • Three-dimensional reconstruction of neutron, gamma-ray, and x-ray sources
           using a cylindrical-harmonics expansion
    • Authors: P. L. Volegov, S. H. Batha, D. N. Fittinghoff, C. R. Danly, V. Geppert-Kleinrath, C. H. Wilde, A. B. Zylstra
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Inertial confinement fusion capsule implosions produce neutron, gamma-ray, and x-ray emission, which are recorded by a variety of detectors, both time integrated and time resolved, to determine the performance of the implosion. Two-dimensional emission images from multiple directions can now be combined to infer three-dimensional structures in the implosion, such as the distribution of thermonuclear fuel density, carbon ablator, and impurities. Because of the cost and complexity of the imaging systems, however, only a few measurements can be made, so reconstructions of the source must be made from a limited number of views. Here, a cylindrical-harmonics decomposition technique to reconstruct the three-dimensional object from two views in the same symmetry plane is presented. In the limit of zero order, this method recovers the Abel inversion method. The detailed algorithms used for this characterization and the resulting reconstructed neutron source from an experiment collected at the National Ignition Facility are presented.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:28Z
      DOI: 10.1063/5.0042860
       
  • Upgrade of the gated laser entrance hole imager G-LEH-2 on the National
           Ignition Facility
    • Authors: Hui Chen, B. Golick, N. Palmer, A. Carpenter, L. D. Claus, M. Dayton, J. Dean, C. Durand, B. Funsten, R. B. Petre, C. M. Hardy, J. Hill, J. Holder, E. Hurd, N. Izumi, J. Kehl, S. Khan, C. Macaraeg, M. O. Sanchez, T. Sarginson, M. B. Schneider, C. Trosseille
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      A major upgrade has been implemented for the ns-gated laser entrance hole imager on the National Ignition Facility (NIF) to obtain high-quality data for Hohlraum physics study. In this upgrade, the single “Furi” hCMOS sensor (1024 × 448 pixel arrays with two-frame capability) is replaced with dual “Icarus” sensors (1024 × 512 pixel arrays with four-frame capability). Both types of sensors were developed by Sandia National Laboratories for high energy density physics experiments. With the new Icarus sensors, the new diagnostic provides twice the detection area with improved uniformity, wider temporal coverage, flexible timing setup, and greater sensitivity to soft x rays (
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:27Z
      DOI: 10.1063/5.0041272
       
  • Operation analysis of the wideband high-power microwave sources based on
           the gyromagnetic nonlinear transmission lines
    • Authors: Yancheng Cui, Jin Meng, Liyang Huang, Yuzhang Yuan, Haitao Wang, Danni Zhu
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The wideband High-Power Microwave (HPM) sources, which combine the advantages of narrowband and ultrawideband sources, have drawn much attention. As a kind of wideband source, the gyromagnetic nonlinear transmission lines (GNLTLs) can directly modulate the incident pulses into radio frequency pulses without relying on the interaction between e-beam and microwaves. Due to the special working mechanism of gyromagnetic precession, the center frequency of the GNLTL can also be adjusted in a certain range. Based on classical magnetism and a simplified model of the GNLTL, this paper semi-quantitatively and theoretically analyzed the generation mechanism of HPM and illustrated the influences of the variations of parameters on the output microwaves. Then, a simple simulation based on 1-dimensional transmission line modeling method was carried out to study the performance of the GNLTL quantitatively, with the coupling of 1D telegraphist equations and the 3D Landau–Lifshitz–Gilbert equation. Simulation results preliminarily verified the conclusions derived from the theoretical analysis, and some working characteristics of the GNLTL were also obtained. This paper may help to understand the special working mechanism of the GNLTL and provide certain guidance for related simulations and experiments.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-02T01:05:25Z
      DOI: 10.1063/5.0040323
       
  • High frame rate emission spectroscopy for ablation tests in plasma wind
           tunnel
    • Authors: Ranjith Ravichandran, David Leiser, Fabian Zander, Stefan Löhle, Pavol Matlovič, Juraj Tóth, Ludovic Ferrière
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This article describes a novel high frame rate emission spectroscopy setup developed for measurements in high enthalpy flow fields. The optical setup and the associated hardware arrangements are described in detail followed by test case data to demonstrate the capability of recording spectral images at 1 kHz frame rate. The new system is based on a classical Czerny–Turner spectrograph but with a particular setup for high frame rate detection using a Generation II intensifier coupled with a high-speed camera. The high frame rate spectral images acquired enable, for the first time, investigation of the spatial distribution and temporal tracking and evolution of molten droplets of an ablating sample. In this paper, an example is shown from ablating meteorite samples tested in a high enthalpy plasma flow field corresponding to a flight scenario at an altitude of 80 km. This new instrumental configuration allows emission spectroscopic analysis of transient phenomena simulated in the high enthalpy ground test facilities with kHz resolution. The particular feature of this system is the ability to measure very faint spectral lines at high temporal and spatial resolution.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:28Z
      DOI: 10.1063/5.0040801
       
  • Spectral sensor error analysis for measuring x-ray radiation drive using
           the DANTE diagnostic toward inertial confinement fusion experiments
    • Authors: C. D. Harris, G. E. Kemp, M. B. Schneider, K. Widmann, M. S. Rubery, M. J. May
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      DANTE is a diagnostic used to measure the x-radiation drive produced by heating a high-Z cavity (“hohlraum”) with high-powered laser beams. It records the spectrally and temporally resolved radiation flux at x-ray energies between 50 eV and 20 keV. Each sensor configuration on DANTE is composed of filters, mirrors, and x-ray diodes to define 18 different x-ray channels whose output is voltage as a function of time. The absolute flux is then determined from the photometric calibration of the sensor configuration and a spectral reconstructing algorithm. The reconstruction of the spectra vs time from the measured voltages and known response of each channel has presented challenges. We demonstrate a novel approach here for quantifying the error on the determined flux based on the channel sensor configuration and most commonly used reconstruction algorithm. In general, we find that the integrated spectral flux from a hohlraum can robustly be reconstructed (within ∼14%) using a traditional unfold approach with as few as ten channels due to the underlying assumption of a largely Planckian spectral intensity distribution.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:28Z
      DOI: 10.1063/5.0035584
       
  • Picosecond high-voltage pulse measurements
    • Authors: M. R. Ulmaskulov, S. A. Shunailov, K. A. Sharypov, E. M. Ulmaskulov
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      This paper presents capacitive sensors based on oxide dielectric substrates that provide a high attenuation factor of up to 30 · 103 with a transient time of ∼38 ps. The sensors made it possible to significantly reduce the number of attenuators and increase the bandwidth of the measuring path. The presented sensors have been used successfully for recording high voltage to MV pulses in the time range from a few nanoseconds to tens of picoseconds. The use of the sensors as the point receiving antennas for recording radio pulses in the GHz frequency range with high electric fields is also discussed, along with the trough directional coupler as a unit for additional attenuation of the voltage of the sensor response. The couplers have a high attenuation factor of 1–5 · 103 with a transient time of ∼38 ps. Using the couplers as attenuators for recording waveforms further improves the parameters (bandwidth, transient time) of the measuring circuit. A discussion of some features of the operational mode of this type of sensor and coupler with a focus on wave processes is also presented. This discussion can be used to analyze the general approaches to the improvement of the sensor and coupler as components of the measuring circuit. In this paper, the authors also propose methods for calibrating and calculating the attenuation factor of the sensors.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:25Z
      DOI: 10.1063/5.0028419
       
  • A compact NaI(Tl) with avalanche photodiode gamma spectrometer for in situ
           radioactivity measurements in marine environment
    • Authors: Zhenyu Sun, Fan Zhou, Zhe Cao, Ziheng Zhou, Xiaohu Wang, Jianhui Yuan, Xiru Huang, Changqing Feng, Ping Cao, Qi An
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      In situ radioactivity measurements in a deep ocean environment are essential for marine environmental pollution monitoring and seabed geological exploration. In the past, the most widely used gamma spectrometers were based on towed instrumentation, which could only be operated underwater at a depth of less than 1500 m. In this study, a compact gamma spectrometer with small-size, light weight, and low power consumption was designed for working in a marine in situ environment. This spectrometer, with two essential parts: detector and electronics, was designed to work on different underwater platforms in the real-time control mode or autonomous operation mode. Multiple small volume avalanche photodiodes were coupled with NaI(Tl), which can significantly reduce the spectrometer volume compared with the option of the photomultiplier tube. Integrated readout electronics were employed to digitize all detector signals for miniaturization and low power consumption. The field programmable gate array (FPGA) was used to obtain the energy spectrum in real-time and an online multi-channel summation with temperature calibration algorithm was employed to improve detection efficiency. Relevant tests were also conducted in the laboratory to evaluate critical techniques and system performance. Results show that the energy resolution (full width at half maximum over the peak position) was ∼7.5% at 662 keV, verifying the online multi-channel summation with temperature calibration based on the FPGA. Moreover, the compact prototype spectrometer worked well in the power-on hydraulic test.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:24Z
      DOI: 10.1063/5.0038534
       
  • An experimental system to evaluate impact shear failure of rock
           discontinuities
    • Authors: Wei Yao, Chonglang Wang, Kaiwen Xia, Xin Zhang
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      Conventionally, the evaluation of shear failure of discontinuities in rocks and other geomaterials has been conducted under static shear loading. In such methods, the shear failure behaviors of rock discontinuities are significantly influenced by loading velocities. To evaluate the shear failure process under dynamic loading, in this paper, we propose a new experimental methodology by taking advantages of recently available high-speed optical and mechanical measurement techniques. The methodology utilizes the Hopkinson bar to apply impact loading, and the diagnostics include a dynamic stress wave acquisition system, a digital image correlation (DIC) system, and an acoustic emission (AE) monitoring system. To improve the accuracy of the DIC analysis, an advanced digital speckle pattern and an updated water transfer printing are used to obtain the optimized and consistent speckle pattern. A flexible piezoelectric film sensor is first introduced to acquire AE signals in order to locate AE events accurately. A dynamic impact shear experiment indicates that the normal stress has a significant effect on the peak shear stress of rock discontinuities and the peak shear stress itself is rate dependent. The displacement field along shear directions is quantified using the DIC method, and the initial AE source locations during the impact shear process are determined using the AE monitoring system. We thus conclude that the dynamic impact shear system can systematically characterize the dynamic impact shear process with quantitative details and can further be implemented to study other dynamic impact failure behaviors of rock discontinuities under in situ stresses.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:23Z
      DOI: 10.1063/5.0032003
       
  • The inductively driven transmission line: A passively coupled device for
           diagnostic applications on the Z pulsed power facility
    • Authors: Clayton E. Myers, Derek C. Lamppa, Christopher A. Jennings, Matthew R. Gomez, Patrick F. Knapp, Michael R. Kossow, Larry M. Lucero, James K. Moore, David A. Yager-Elorriaga
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      The inductively driven transmission line (IDTL) is a miniature current-carrying device that passively couples to fringe magnetic fields in the final power feed on the Z Pulsed Power Facility. The IDTL redirects a small amount of Z’s magnetic energy along a secondary path to ground, thereby enabling pulsed power diagnostics to be driven in parallel with the primary load for the first time. IDTL experiments and modeling presented here indicate that IDTLs operate non-perturbatively on Z and that they can draw in excess of 150 kA of secondary current, which is enough to drive an X-pinch backlighter. Additional experiments show that IDTLs are also capable of making cleaner, higher-fidelity measurements of the current flowing in the final feed.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:22Z
      DOI: 10.1063/5.0043810
       
  • Measurements of dynamic surface changes by digital holography for in situ
           plasma erosion applications
    • Authors: C. D. Smith, T. M. Biewer, T. E. Gebhart, E. G. Lindquist, C. E. Thomas
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      There are currently few viable diagnostic techniques for in situ measurement of plasma facing component erosion. Digital holography is intended to fill this gap. Progress on the development of single and dual CO2 laser digital holography diagnostics for in situ plasma facing component erosion is discussed. The dual laser mode’s synthetic wavelength allows the measurable range to be expanded by a factor of ∼400 compared to single laser digital holography. This allows the diagnostic to measure surface height changes of up to 4.5 μm in single laser mode and up to 2 mm in dual laser mode. Results include ex situ measurements of plasma eroded targets and also dynamic measurements of nm and μm scale motion of a target mounted on a precision translation stage. Dynamic measurements have successfully been made with the system operating in both single and dual laser modes, from ∼50 nm to ∼4 μm in single laser mode and up to ∼400 μm in dual laser mode (limited only by the stage speed and camera acquisition duration). These results demonstrate the feasibility of using digital holography to characterize plasma facing component erosion dynamically, i.e., during plasma exposure. Results of proof-of-principle in situ digital holographic measurements of targets exposed to an electrothermal arc plasma source are presented.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:22Z
      DOI: 10.1063/5.0040566
       
  • Characterization of signals for a Divertor Tokamak Test facility
           interferometer/polarimeter system
    • Authors: D. Fiorucci, L. Giudicotti, P. Innocente, D. Terranova, C. Mazzotta, O. Tudisco
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      In magnetically confined fusion experiments, laser interferometer/polarimeter systems allow one to determine plasma density, give valuable information on the internal magnetic fields, and contribute to the evaluation of the plasma magnetic equilibrium and to the real-time estimation of the q profile to allow feedback configuration control. This work presents an analysis of the interferometric and polarimetric signals of a multi-chord far-infrared interferometer/polarimeter for the divertor tokamak test facility, the new tokamak device currently under construction in Italy. The polarimetric signals are calculated both with approximate formulas and by solving the equation describing the evolution of the laser beam polarization inside the plasma using the Mueller formalism. The latter method correctly accounts for crosstalk between Faraday rotation and the Cotton–Mouton effect. The impact of the plasma birefringence on the interferometric phase shift is also studied, and it is found that a perturbation of the interferometric phase shift is present also in the case of an initial fixed linear polarization of the probe laser beam.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T12:49:21Z
      DOI: 10.1063/5.0043516
       
  • Measurement of L-shell emission from mid-Z targets under non-LTE
           conditions using Transmission Grating Spectrometer and DANTE power
           diagnostics
    • Authors: M. Fraenkel, Y. Ehrlich, Z. Shpilman, Z. Henis, Y. Frank, E. V. Marley, G. Pérez-Callejo, J. Emig, R. F. Heeter, D. A. Liedahl, M. E. Foord, M. B. Schneider
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      In this work, we present the measurement of L-band emission from buried Sc/V targets in experiments performed at the OMEGA laser facility. The goal of these experiments was to study non-local thermodynamic equilibrium plasmas and benchmark atomic physics codes. The L-band emission was measured simultaneously by the time resolved DANTE power diagnostic and the recently fielded time integrated Soreq-Transmission Grating Spectrometer (TGS) diagnostic. The TGS measurement was used to support the spectral reconstruction process needed for the unfolding of the DANTE data. The Soreq-TGS diagnostic allows for broadband spectral measurement in the 120 eV–2000 eV spectral band, covering L- and M-shell emission of mid- and high-Z elements, with spectral resolution λ/Δλ = 8–30 and accuracy better than 25%. The Soreq-TGS diagnostic is compatible with ten-inch-manipulator platforms and can be used for a wide variety of high energy density physics, laboratory astrophysics, and inertial confinement fusion experiments.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T06:59:32Z
      DOI: 10.1063/5.0040574
       
  • Absolute x-ray calibration of a gated x-ray framing camera for the Laser
           MegaJoule facility in the 0.1 keV–1 keV spectral range
    • Authors: S. Hubert, F. Boubault
      Abstract: Review of Scientific Instruments, Volume 92, Issue 3, March 2021.
      X-ray framing cameras (XRFCs) are routinely used at the Laser MegaJoule facility in x-ray imaging plasma diagnostics around the target chamber. Most of these diagnostics are based on multilayer x-ray toroidal mirrors under grazing incidence. The absolute calibration of the XRFCs is expressly expected both to optimize the signal-to-noise ratio for the dynamic range for specific experiments and to quantitatively process the data. The purpose of this paper is to describe our technique to routinely calibrate these instruments in the sub-keV spectral range. The calibration presented in this work was carried out using the XRFC enclosed in a sealed “airbox” structure. This calibration relies on a Manson source recently upgraded to operate at high emission current (5 mA) with 10 kV accelerating voltage to work with a 1-m grazing-incidence Rowland circle monochromator. The framing camera sensitivity was absolutely determined over the 0.1–1.2 spectral range with an average uncertainty of 2.4% rms while operating in DC mode. Finally, we compare the results with a synchrotron source calibration previously obtained and a theoretical model.
      Citation: Review of Scientific Instruments
      PubDate: 2021-03-01T01:57:49Z
      DOI: 10.1063/5.0004105
       
 
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