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PHYSICS (536 journals)            First | 1 2 3 4 5 6 | Last

ECS Journal of Solid State Science and Technology     Full-text available via subscription  
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 4)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 14)
Energy Procedia     Open Access   (Followers: 2)
Engineering Failure Analysis     Hybrid Journal   (Followers: 22)
Engineering Fracture Mechanics     Hybrid Journal   (Followers: 15)
Environmental Fluid Mechanics     Hybrid Journal   (Followers: 2)
EPJ Nonlinear Biomedical Physics     Open Access  
EPJ Web of Conferences     Open Access  
European Journal of Physics     Full-text available via subscription   (Followers: 4)
European Journal of Physics Education     Open Access   (Followers: 5)
European Physical Journal - Applied Physics     Full-text available via subscription   (Followers: 4)
European Physical Journal C     Hybrid Journal  
Europhysics News     Open Access   (Followers: 1)
Experimental Mechanics     Hybrid Journal   (Followers: 14)
Experimental Methods in the Physical Sciences     Full-text available via subscription  
Experimental Techniques     Hybrid Journal   (Followers: 15)
Exploration Geophysics     Hybrid Journal   (Followers: 3)
Few-Body Systems     Hybrid Journal  
Fire and Materials     Hybrid Journal   (Followers: 4)
Flexible Services and Manufacturing Journal     Hybrid Journal   (Followers: 2)
Fluctuation and Noise Letters     Hybrid Journal   (Followers: 1)
Fluid Dynamics     Hybrid Journal   (Followers: 5)
Fortschritte der Physik/Progress of Physics     Hybrid Journal  
Frontiers in Physics     Open Access   (Followers: 2)
Frontiers of Materials Science     Hybrid Journal   (Followers: 4)
Frontiers of Physics     Hybrid Journal   (Followers: 1)
Fusion Engineering and Design     Hybrid Journal   (Followers: 2)
Geochemistry, Geophysics, Geosystems     Full-text available via subscription   (Followers: 21)
Geografiska Annaler, Series A: Physical Geography     Hybrid Journal   (Followers: 3)
Geophysical Research Letters     Full-text available via subscription   (Followers: 41)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 19)
Glass Physics and Chemistry     Hybrid Journal   (Followers: 1)
Granular Matter     Hybrid Journal   (Followers: 2)
Graphs and Combinatorics     Hybrid Journal   (Followers: 5)
Handbook of Geophysical Exploration: Seismic Exploration     Full-text available via subscription  
Handbook of Metal Physics     Full-text available via subscription  
Handbook of Surface Science     Full-text available via subscription   (Followers: 2)
Handbook of Thermal Analysis and Calorimetry     Full-text available via subscription  
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Heat Transfer - Asian Research     Hybrid Journal   (Followers: 5)
High Energy Density Physics     Hybrid Journal   (Followers: 1)
High Pressure Research: An International Journal     Hybrid Journal   (Followers: 1)
IEEE Journal of Quantum Electronics     Hybrid Journal   (Followers: 12)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 21)
IET Optoelectronics     Hybrid Journal   (Followers: 2)
Il Colle di Galileo     Open Access  
Imaging Science Journal, The     Hybrid Journal   (Followers: 2)
Indian Journal of Biochemistry and Biophysics (IJBB)     Open Access   (Followers: 4)
Indian Journal of Physics     Hybrid Journal   (Followers: 4)
Indian Journal of Pure & Applied Physics (IJPAP)     Open Access   (Followers: 8)
Indian Journal of Radio & Space Physics (IJRSP)     Open Access   (Followers: 4)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Infinite Dimensional Analysis, Quantum Probability and Related Topics     Hybrid Journal  
InfraMatics     Open Access  
Infrared Physics & Technology     Hybrid Journal  
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 1)
Intermetallics     Hybrid Journal   (Followers: 4)
International Applied Mechanics     Hybrid Journal   (Followers: 2)
International Geophysics     Full-text available via subscription   (Followers: 3)
International Heat Treatment & Surface Engineering     Hybrid Journal   (Followers: 2)
International Journal for Computational Methods in Engineering Science and Mechanics     Hybrid Journal   (Followers: 8)
International Journal for Ion Mobility Spectrometry     Hybrid Journal   (Followers: 1)
International Journal for Simulation and Multidisciplinary Design Optimization     Full-text available via subscription   (Followers: 1)
International Journal of Abrasive Technology     Hybrid Journal   (Followers: 2)
International Journal of Aeroacoustics     Full-text available via subscription   (Followers: 6)
International Journal of Applied Electronics in Physics & Robotics     Open Access  
International Journal of Astronomy and Astrophysics     Open Access   (Followers: 3)
International Journal of Computational Materials Science and Surface Engineering     Hybrid Journal   (Followers: 7)
International Journal of Damage Mechanics     Hybrid Journal   (Followers: 5)
International Journal of Fatigue     Hybrid Journal   (Followers: 5)
International Journal of Fracture     Hybrid Journal   (Followers: 8)
International Journal of Geometric Methods in Modern Physics     Hybrid Journal   (Followers: 1)
International Journal of Geophysics     Open Access   (Followers: 3)
International Journal of Heat and Fluid Flow     Hybrid Journal   (Followers: 9)
International Journal of Low Radiation     Hybrid Journal  
International Journal of Low-Carbon Technologies     Open Access   (Followers: 1)
International Journal of Mass Spectrometry     Hybrid Journal   (Followers: 11)
International Journal of Material Forming     Hybrid Journal   (Followers: 2)
International Journal of Materials and Product Technology     Hybrid Journal   (Followers: 4)
International Journal of Mechanical Sciences     Hybrid Journal   (Followers: 5)
International Journal of Mechanics and Materials in Design     Hybrid Journal   (Followers: 5)
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology     Open Access   (Followers: 4)
International Journal of Micro-Nano Scale Transport     Full-text available via subscription   (Followers: 1)
International Journal of Microstructure and Materials Properties     Hybrid Journal   (Followers: 7)
International Journal of Microwave Science and Technology     Open Access   (Followers: 2)
International Journal of Modeling, Simulation, and Scientific Computing     Hybrid Journal   (Followers: 1)
International Journal of Modern Physics A     Hybrid Journal   (Followers: 1)
International Journal of Modern Physics B     Hybrid Journal  
International Journal of Modern Physics C     Hybrid Journal  
International Journal of Modern Physics D     Hybrid Journal  
International Journal of Modern Physics E     Hybrid Journal   (Followers: 1)
International Journal of Nanomanufacturing     Hybrid Journal   (Followers: 1)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Nanotechnology     Hybrid Journal   (Followers: 4)
International Journal of Non-Linear Mechanics     Hybrid Journal   (Followers: 4)
International Journal of Physical Sciences     Open Access  
International Journal of PIXE     Hybrid Journal   (Followers: 1)
International Journal of Plasticity     Hybrid Journal   (Followers: 6)

  First | 1 2 3 4 5 6 | Last

Journal Cover Contributions to Plasma Physics
   [4 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0863-1042 - ISSN (Online) 1521-3986
     Published by John Wiley and Sons Homepage  [1602 journals]   [SJR: 0.612]   [H-I: 29]
  • Cover Picture: Contrib. Plasma Phys. 4–6/2014
    • Pages: n/a - n/a
      Abstract: 3-D DEGAS-2 simulation of NSTX Gas Puff Imaging (GPI) experiment. The equally spaced white contours are computed from the time averaged GPI images for shot #141324; the color contours represent the DEGAS-2 simulated camera image. (Figure 5b of the paper by J. N. Brooks et al.)
      PubDate: 2014-06-20T08:26:35.327879-05:
      DOI: 10.1002/ctpp.201490006
  • Issue Information Picture: Contrib. Plasma Phys. 4–6/2014
    • Pages: n/a - n/a
      PubDate: 2014-06-20T08:26:34.331902-05:
      DOI: 10.1002/ctpp.201490007
  • Computational Model of Thermal‐Fluid Flow in a Radio‐Frequency
           Plasma Torch
    • Authors: N. Ikhlef; O. Leroy, M. R. Mekideche
      Abstract: The paper aims to clarify the modelling results concerning the heat transfer and fluid flow in a radio‐frequency plasma torch with argon at atmospheric pressure. Fluid numerical simulation requires the coupling of magnetohydrodynamics (MHD) and thermal phenomena. This model combines Navier–Stokes equations with the Maxwell's equations for compressible fluid and electromagnetic phenomena successively. A numerical formulation based on the finite element method is used. In this study, fluid flow and temperature equations are simultaneously solved (direct method, instead of using the indirect method) using a finite elements method (FEM) for optically thin argon plasmas under the assumptions of local thermodynamic equilibrium (LTE) and laminar flow. Appropriate boundary conditions are given, and nonlinear parameters such as the thermal and electrical conductivity of the gas and input power used in the simulation are detailed. We have found that the source of power is located on the torch wall in this type of inductive discharge. The center can be heated by conduction and convection via electromagnetic phenomena (power loss and Lorentz force). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T04:30:06.263663-05:
      DOI: 10.1002/ctpp.201300056
  • Effect of Anisotropic Ion Pressure on Solitary Waves in Magnetized Dusty
    • Authors: M. Adnan; S. Mahmood, Anisa Qamar
      Abstract: The propagation of linear and nonlinear dust ion acoustic waves (DIAWs) are studied in a collisionless magnetized plasma which consists of warm ions having anisotropic thermal pressure, nonthermal (energetic) electrons and static dust particles of positive and negative charge polarity. The anisotropic ion pressure is defined using double adiabatic Chew‐Golberger‐Low (CGL) theory. In the linear regime, the propagation properties of the two possible modes are investigated via ion pressure anisotropy, dust particle polarity and nonthermality of electrons. Using reductive method Zakharov‐Kuznetsov (ZK) equation is derived for the propagation of two dimensional electrostatic dust ion acoustic solitary waves in dusty plasmas. It is found that both compressive and rarefactive solitons are formed in presence of nonthermal electrons using Cairn's distribution [R.A. Cairns, A.A. Mamun, R. Bingham, R.O. Dendy, R. Bostrom, C.M.C. Nairn and P.K. Shukla, Geophys.Res. Lett. 22, 2709 (1995)] in the system. The ion pressure anisotropy, nonthermality of electrons and charge polarity of the dust particles have significant effects on the amplitude and width of the dust ion acoustic solitary waves in such anisotropic nonthermal magnetized dusty plasmas. The numerical results are also presented for illustration. Our finding is applicable to space dusty plasma regimes having anisotropic ion pressure and nonthermal electrons. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-03-31T02:10:05.122447-05:
      DOI: 10.1002/ctpp.201300061
  • Diagnostic of Plasma Produced by a Spark Plug at Atmospheric Pressure:
           Reduced Electric Field and Vibrational Temperature
    • Authors: B. Hnatiuc; D. Astanei, S. Pellerin, N. Cerqueira, M. Hnatiuc
      Abstract: The electric discharge generated between the electrodes of a classic spark plug could not assure a fast and total combustion of the air – hydrocarbon mixture. To be able to improve the quality of the combustion process through the ignition system improvement it is necessary to have a complete diagnostic of the discharge produced by a spark plug, from physical and chemical point of view. This work presents a comparative study of the reduced electric field and the vibrational temperature for a classic spark produced in air at atmospheric pressure, as functions of pulses widths applied by the power supply. The reduced electric field was calculated by using the rotational temperature values established by a previous study, considering them as temperature plasma gas temperatures. The vibrational temperature was determined by using the N2second positive molecular emission spectra. The spark plug was supplied with trains of pulses containing one or two pulses having variable widths provided by a special power supply. The results obtained for the vibrational temperature of nitrogen molecules are close to these obtained for the rotational temperature calculated by using a spectroscopic diagnostic method based on the OH UV molecular band spectra (between 2000 and 3500 K). The electron temperature values, imposed by the reduced electric field (up to 2000 Td), are superior to 10000 K. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-03-24T08:10:11.164267-05:
      DOI: 10.1002/ctpp.201300059
  • Self‐Force in 1D Electrostatic Particle‐in‐Cell Codes
           for NonEquidistant Grids
    • Authors: J. Duras; K. Matyash, D. Tskhakaya, O. Kalentev, R. Schneider
      Abstract: Effects of non‐equidistant grids on momentum conservation is studied for simple test cases of an electrostatic 1D PIC code. The aim is to reduce the errors in energy and momentum conservation. Assuming an exact Poisson solver only numerical errors for the particle mover are analysed. For the standard electric field calculation using a central‐difference scheme, artificial electric fields at the particle position are generated in the case when the particle is situated next to a cell size change. This is sufficient to destroy momentum conservation. A modified electric field calculation scheme is derived to reduce this error. Independent of the calculation scheme additional fake forces in a two‐particle system are found which result in an error in the total kinetic energy of the system. This contribution is shown to be negligible for many particle systems. To test the accuracy of the two electric field calculation schemes numerical tests are done to compare with an equidistant grid set‐up. All tests show an improved momentum conservation and total kinetic energy for the modified calculation scheme of the electric field. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-02-19T06:20:17.124273-05:
      DOI: 10.1002/ctpp.201300060
  • Potential Formation in Front of an Electrode Close to the Plasma Potential
           Studied by PIC Simulation
    • Authors: T. Gyergyek; J. Kovačič
      Abstract: Potential formation in front of an electrode that has the potential which is close to the plasma potential is studied by particle‐in‐cell (PIC) simulations. The code BIT1 [D. Tskhakaya, R. Schneider, J. Comp. Phys., 225, 829 (2007)] is used for this purpose. It is shown that this code is very appropriate for our analysis because of its ability to create charged particles by uniform volume production in the entire system and to maintain in the same time the Maxwellian electron velocity distribution function prescribed in the input file. It turns out that some modifications of the code are necessary in order to achieve small sheath potential drops and to detect the cutoff in the electron velocity distribution function. The modifications of the code are described. The small sheath potential drop is achieved by introducing a finite reflectivity of the electrons at the left electrode, while the expected cutoffs of the electron velocity distribution function are found by tracking the reflected electrons as separate particle species. The simulation results are compared to the theoretical model of Jelić [N. Jelić, Phys. Plasmas, 18, 113504 (2011)]. The matching is very good and this is a sign that the PIC simulations are very appropriate tool for the analysis of this type of problems. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-02-03T11:10:13.265507-05:
      DOI: 10.1002/ctpp.201300036
  • Angular Velocity Distribution of the Electric Microfield in Plasma
    • Authors: H. Adaika; M. T. Meftah
      Abstract: In theory of the spectral line shapes, the conventional scheme use two approximations for the local electric field (microfield) due to all charged particles of the plasma. The quasi‐static approximations for the ions and the impact approximation for the electrons. The first approximation consists to say that the electric field is constant during the characteristic time. In this work we shall transpose the idea of the first approximation, to the angular velocity of the microfield whereas its strength is kept constant and equal to its mean value. We shall use the Holtsmark approach and the independent particles model (due to Margeneau and Lewis) to compute the static distribution function of the angular velocity of the microfield. In the first approach (Holtsmark), the distribution shows a Lorentzian behavior, whereas the second approach (Margenau and Lewis) shows a gaussian behavior. Subsequently, we have applied the obtained static distribution to show the effect on the broadening of Lyman‐alpha line for a plasma composed of He+ ions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-02-03T11:10:12.03632-05:0
      DOI: 10.1002/ctpp.201300041
  • Wave Generation in a Warm Magnetized Multi‐Component Plasma
    • Authors: G. Brodin; L. Stenflo
      Abstract: The resonant interaction between three waves propagating perpendicularly to an external magnetic field in a plasma is considered. We present the explicit expressions for the three wave coupling coefficients of a warm multi‐component plasma. The results of previous work on the generation of THz radiation by laser plasma interaction are significantly improved.
      PubDate: 2014-02-03T11:10:11.154346-05:
      DOI: 10.1002/ctpp.201300054
  • Comparative Plasma Chemical Reaction Studies of CH4/Ar and C2Hm/Ar (m =
           2,4,6) Gas Mixtures in a Dielectric Barrier Discharge
    • Authors: H. C. Thejaswini; S. Peglow, U. Martens, V. Sushkov, R. Hippler
      Abstract: Plasma chemical reactions in CH4/Ar and C2Hm/Ar (m = 2, 4, 6) gas mixtures in a dielectric barrier discharge at medium pressure (300 mbar) have been investigated. From mass spectrometry the production of H2 and formation of larger hydrocarbons such as CnHm with up to n = 12 is inferred. Hydrogen release is most pronounced for CH4 and C2H6 gas mixtures. Fourier Transform InfraRed (FTIR) spectroscopy reveals the formation of substituted alkane (sp3), alkene (sp2), and alkyne (sp) groups from the individual gases which are used in this work. Abundant formation of acetylene occurs from C2H4 and to a lesser extent from C2H6 and CH4 precursor gases. The main reaction pathway of acetylene leads to the formation of large molecules via C4H2 and, eventually, to nano‐size particles. The experimental results are in reasonable agreement with simulations which predict a pronounced electron temperature and gas pressure dependency. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-02-03T10:40:06.178298-05:
      DOI: 10.1002/ctpp.201300035
  • Ion Charge Separation in a Multi‐Species Plasma Flowing through a
           Magnetic Transport System
    • Authors: V. L. Paperny; Yu. V. Korobkin, V. I. Krasov, N. V. Lebedev
      Abstract: Energy spectra of ions of various charged states at different cross‐section of a titanium plasma flow produced with a dc vacuum arc were studied. It was established that ions with different charges states were spatially separated during their travel through a plasma transport system based on a curved magnetic field. Ions with greater charge states were concentrated in the inner part of the curved plasma flow, i.e. closer to the centre of curvature of the field lines, so that the average charge state of ions in this area was higher than that at the outer part of the flow. A computer simulation of guiding a multi‐species plasma flow by a curved magnetic field qualitatively agreed with the experimental data. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-02-03T10:10:07.34117-05:0
      DOI: 10.1002/ctpp.201200060
  • Contents: Contrib. Plasma Phys. 4–6/2014
    • Pages: 321 - 326
      PubDate: 2014-06-20T08:26:38.151213-05:
      DOI: 10.1002/ctpp.201410002
  • Preface: Contrib. Plasma Phys. 4–6/2014
    • Authors: Roman Zagórski
      Pages: 327 - 328
      PubDate: 2014-06-20T08:26:35.37138-05:0
      DOI: 10.1002/ctpp.201410003
  • Scientific and Computational Challenges in Coupled Plasma
           Edge/Plasma-Material Interactions for Fusion Tokamaks
    • Authors: J. N. Brooks; A. Hassanein, A. Koniges, P. S. Krstic, T. D. Rognlien, T. Sizyuk, V. Sizyuk, D. P. Stotler
      Pages: 329 - 340
      Abstract: Plasma/material interactions is a critical scientific issue for fusion power, with major potential limitations on plasma core and edge operating parameters. Gaining understanding and predictive capability in this area will require simultaneously addressing complex and diverse physics occurring over a wide range of lengths (angstroms to meters) and times (femtoseconds to days). This requires further development and validation of detailed physics models and computational strategies at each of these scales. The overriding numerical need is for petascale real-time coupling between 3-D material response/evolution/trapping codes, plasma edge/SOL codes, and impurity transport codes. We discuss selected science and modeling/computational challenges in this area and our ideas for achieving these goals; this from the standpoint of our existing simulation codes. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:39.324957-05:
      DOI: 10.1002/ctpp.201410014
  • Integrated Core-SOL Simulations of ITER H-Mode Scenarios with Different
           Pedestal Density
    • Authors: I. Ivanova-Stanik; F. Koechl, I. Voitsekhovitch, G. Telesca, R. Zagörski, EU-ITM ITER Scenario Modelling group
      Pages: 341 - 346
      Abstract: Fusion performance of ITER H-mode plasmas in presence of intrinsic (He, Be and W) and seeded (Ne) im purities is investigated in self-consistent core-pedestal-SOL simulations for two values of pedestal density npede = 6.12 × 1019m–3 (reference case) and 9 × 1019m–3 using the JETTO and COREDIV codes iteratively. The theory-based GLF23 transport model which predicts a relatively high density peaking (ne0/〈ne〉 = 1.37 ÷ 1.39) has been used for this study. For medium density case the H-mode operation with a power across the separatrix well above the L-H power threshold has been obtained, but the divertor heat loads exceed 10 MW/m2. Neon gas puff strongly reduces the power to divertor plate in this scenario, increasing at the same time the tungsten sputtering by Ne that leads to even larger core radiation and dilution, than in the case without Ne. As a result, the medium density H-mode operation with Ne seeding and low divertor heat loads is barely above the L-H power threshold. This operational point is weakly sensitive to tungsten inward pinch due to a strong coupling between W transport, radiation and sputtering. At high density with much larger core radiation (90 MW), the possibility of H-mode operation strongly depends on the choice transport model, with the power through the separatrix well below (above) the L-H power threshold in simulations with the GLF23 (H98y scaling-based) transport model. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.217619-05:
      DOI: 10.1002/ctpp.201410050
  • Numerical Scaling with the COREDIV Code of JET Discharges with the
           ITER-Like Wall
    • Authors: G. Telesca; I. Ivanova-Stanik, R. Zagörski, S. Brezinsek, C. Giroud, G. Van Ooost, JET EFDA contributors
      Pages: 347 - 352
      Abstract: After the code parameters have been fixed by the numerical modeling of a well diagnosed JET pulse, the electron density and the input power have been changed, resulting in 4 density scans (〈ne〉 in the range 3.8 – 8.2 x 1019m-3) at Pin = 17, 22, 27, 32 MW. At any given power level, W flux decreases with increasing 〈ne〉 as a consequence of the decrease in Te at the target plates. Also the W concentration in the core (cW) decreases, but this not necessarily leads to reduced core radiation. Indeed, while at high Pin the core radiation decreases with density, at low Pin it increases. At high 〈ne〉 the increase in the input power leads to enhanced PradPrad, leaving, however, nearly unchanged the power radiated fraction frad Indeed, the increase in frad withPin is observed only at low 〈ne〉, up to a level of about frad = 0.4. These numerical results, linked to the non-linear self-consistent physics of W production and transport, suggest the best conditions are achieved when the level of the electron density is adapted to the level of the available Pin. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.04499-05:0
      DOI: 10.1002/ctpp.201410052
  • Self-Consistent COREDIV Modelling of WEST Plasma Scenarios
    • Authors: Y. Marandet; I. Ivanova-Stanik, R. Zagörski, C. Bourdelle, J. Bucalossi, H. Bufferand, G. Ciraolo, E. Tsitrone
      Pages: 353 - 357
      Abstract: The importance of core-edge coupling in the WEST tokamak via tungsten production and core radiation is investigated with the COREDIV code. We first focus on the idealized situation where the plasma is free of light impurities, and show that for achievable high density discharges tungsten production can be essentially extinguished. For lower densities, core edge coupling is strong, that is tungsten plays a major role in regulating the power flowing through the Scrape-off layer. The latter is found to saturate with increasing heating power due to increasing radiation losses in the core. Then we investigate the extent to which light impurities change this picture by performing a scan in boron concentration, since Ion Cyclotron Resonance Heating antenna protections may be boron coated. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:34.152889-05:
      DOI: 10.1002/ctpp.201410051
  • Limit on Reduction of the Power Load to Target Plates for DEMO Reactor
    • Authors: R. Stankiewicz; W. Stępniewski
      Pages: 358 - 362
      Abstract: The several Demo design concepts have been analyzed using the code Corediv solving self consistently the core and scrape off layer regions. The numerical analyses show that there exists the limit on the concentration of impurities above which the solution with burning plasma does not exists. This limits reduce the possibility of reduction of power loads to target plate. In the paper the admissible range of seeded impurity concentration introduced to reduce the power load to divertor plate is analyzed. The possible mechanisms leading to the limitation are shown. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.900744-05:
      DOI: 10.1002/ctpp.201410022
  • Simulation Study of Nonlocal Transport from Edge to Core in Tokamak
    • Authors: M. Yagi; A. Matsuyama, N. Miyato, T. Takizuka
      Pages: 363 - 367
      Abstract: The simulation study of nonlocal transport from edge to core in tokamak plasmas is performed using the 4-field reduced MHD model. A toroidally-elongated cylindrical particle source is applied in the plasma edge, after saturation of the resistive ballooning turbulence is attained. After a short time, the source is switched off and plasma response is investigated in detail. The nonlocal transport appears at the location far from the edge source. It is found that the particle source induces (0,0) and (±1, 0) modes of density fluctuations, where (m, n) indicates the set of poloidal mode number m and the toroidal mode number n. These modes interact with each other by the nonlinear and/or toroidal couplings. The symmetry of (±1, 0) modes breaks after switching-off the source and the formation of the spiral structure with poloidal rotation is observed, which yields a connection between core and edge regions. In this simulation, the convective cell mode such as (1,0) mode contributes the nonlocal transport. The simulation result indicates that two dimensional transport plays an essential role to produce the nonlocal transport. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.402696-05:
      DOI: 10.1002/ctpp.201410042
  • A Simple Hybrid Model for SOL, Pedestal and Core Tokamak Plasmas
    • Authors: A. S. Bykov; V. Yu. Sergeev, B.V. Kuteev
      Pages: 368 - 372
      Abstract: In this paper, the divertor heat flux density profile is being discussed. The simple robust model, dealing with core, pedestal and edge plasmas was improved. The model was applied to the ITER basic regime. Heat flux density was estimated for two different cases of heat flux SOL width of ITER. In the case of wide 2 cm SOL, the peak divertor heat flux density is under technological limit of 10 MW/m2. In the case of quite narrow 1 mm width SOL, peak divertor heat flux density exceeds this limit by several times and detached divertor regimes should be considered. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:33.527365-05:
      DOI: 10.1002/ctpp.201410030
  • Numerical Fluid Modelling of the Plasma Edge Response to a 3D Object and
           Application to Mach Probe Measurements
    • Authors: A. Paredes; E. Serre, F. Schwander, Ph. Ghendrih, P. Tamain
      Pages: 373 - 377
      Abstract: The penalization method Ref. [1] is used to model the interaction of 3D probe with an isothermal plasma. Density maps show that the region perturbed by the obstacle, is not restricted to its near neighbourhood, but can extend to the whole SOL. In the particular case of a probe, which is used to measure local plasma parameters, this impact can lead to violation of assumptions of locality of the perturbation usually used in determining Mach number from the imbalance in density on both sides of the probe. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.547636-05:
      DOI: 10.1002/ctpp.201410028
  • Density Regimes and Heat Flux Deposition in the WEST Shallow Divertor
    • Authors: H. Bufferand; J. Bucalossi, G. Ciraolo, N. Fedorczak, P. Ghendrih, R. Leybros, Y. Marandet, E. Serre, P. Tamain
      Pages: 378 - 382
      Abstract: To support ITER divertor design, the WEST project on Tore Supra aims at studying high heat fluxes on tungsten monoblock during long pulses. In that persective, a particular attention is paid to simulate the edge plasma interaction with complex PFCs using the transport code SOLEDGE2D-EIRENE. The plasma response to a heating and puffing scenario is described as well as the so-called divertor density regimes, characterizing the operational domain of the WEST divertor. These results are compared for two different magnetic configurations: a semi-open double null divertor with the X-point away from the target plates and a shallow divertor configuration with the X-point close to the targets. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.032545-05:
      DOI: 10.1002/ctpp.201410026
  • Benchmark of Monte Carlo Scheme of EMC3 Dealing with NonUniform
           Cross-Field Transport Coefficients and Implementation in LHD
    • Authors: M. Kobayashi; Y. Feng, I. Yamada, H. Hayashi, G. Kawamura
      Pages: 383 - 387
      Abstract: The new code version of EMC3, which can deal with non-uniform cross-field transport coefficient, is benchmarked with analytical problem and a finite difference method. It has been confirmed that for arbitrary spatial change of the transport coefficient the error is suppressed below tolerable level for the purpose of comparison with experiments. The first implementation of the new code in LHD stochastic layer shows existence of significant change of cross-field transport in radial direction. The location of the change corresponds to the boundary between long flux tubes region and the edge surface layers (where long and short flux tubes co-exist, i.e. laminar zone). (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.906223-05:
      DOI: 10.1002/ctpp.201410015
  • Simple and Fast Poisson Solver with Arbitrary Boundary Shape and Condition
           for PIC Simulation
    • Authors: T. Takizuka; S. Azuma, A. Fukuyama, K. Shimizu
      Pages: 388 - 393
      Abstract: Particle-in-cell (PIC) simulations are the very powerful method to understand physics of edge plasmas in fusion devices. Poisson solver with a regular grid in a rectangular vessel is very fast, but it cannot simply be applicable to simulations in complicated divertor configuration. In this paper, a simple and fast Poisson solver with arbitrary boundary shape and condition for PIC simulation is proposed. Boundary points are essential for this Poisson solver, on which the charge density is appropriately given and the boundary condition is satisfied. For particle simulations in the open system, it is necessary to distinguish whether a traced particle moves freely or hits the wall boundary during a time step. A new method for PIC simulation to discriminate a particle position before the boundary or beyond the boundary is also presented. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.967555-05:
      DOI: 10.1002/ctpp.201410043
  • Numerical Modeling of the Thermal Force for the Kinetic Test-Ion Transport
           Simulation Based on the Fokker-Planck Collision Operator
    • Authors: Y. Homma; A. Hatayama
      Pages: 394 - 398
      Abstract: We present an extended numerical model of the thermal force based on the Fokker-Planck collision method. Our model is designed for the use of the test particle transport simulation in a fluid-like magnetized background plasma. By a series of systematic test simulations performed in this study, we have confirmed that our model is able to correctly simulate the thermal force which is caused not only by parallel, but also by perpendicular temperature gradient with respect to the direction of magnetic field. Effective length of collision time step for numerical calculations has also been investigated. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.010168-05:
      DOI: 10.1002/ctpp.201410049
  • Implementation of PIC/MC Code BIT1 in ITM Platform
    • Authors: D. Tskhakaya; D. Coster, ITM-TF contributors
      Pages: 399 - 403
      Abstract: We describe the development of the user friendly version of massively parallel PIC code BIT1 for plasma edge simulations and its implementation into the Integrated Tokamak Modeling (ITM) platform. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.764724-05:
      DOI: 10.1002/ctpp.201410029
  • Development of the Backflow Model for Simplified Impurity Exhaust in
           Monte-Carlo Calculation
    • Authors: K. Hoshino; K. Shimizu, H. Kawashima, T. Takizuka, T. Nakano, S. Ide
      Pages: 404 - 408
      Abstract: The Monte-Carlo (MC) approach has a lot of flexibility in impurity transport modeling in the SOL and divertor region. However, in the divertor plasma simulation with the noble impurity seeding, characteristic time of the impurity transport especially in the sub-divertor chamber is long because the MC calculation of the impurity gas transport can be finished only by exhaust. The impurity MC calculation for such long exhaust processes is difficult in a series of the iterative calculation of a suite of integrated divertor codes SONIC. In order to overcome such a problem, a backflow model has been developed. Amount of the backflow flux from the sub-divertor chamber to the divertor region is evaluated in advance, and then simulating impurity flux is injected from the exhaust slot to the divertor region like a backflow. By this model, the MC calculation time is reduced significantly and iterative calculation of SONIC becomes possible within a reasonable calculation time. As a demonstration, the SONIC code with the backflow model has been applied to investigation of power handling in JT-60SA divertor. The SONIC simulation showed that low divertor heat load (< 10 MW/m2) with the low SOL density (< 1.5 × 1019m–3), which is required in the full non-inductive current drive scenario, was achieved by the Ar gas puffing of 0.86 Pa m3/s. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.256089-05:
      DOI: 10.1002/ctpp.201410032
  • Effect of Turbulent Fluctuations on Neutral Particle Penetration and
           Charge Exchange Sputtering
    • Authors: A. Mekkaoui; V. Kotov, D. Reiter, P. Boerner
      Pages: 409 - 414
      Abstract: In this contribution we present results on the effect of turbulent plasma fluctuations on the transport of atoms and molecules as well as on impurities sputtered due to charge exchange atomic bombardment. These phenomena are investigated using the kinetic Monte-Carlo particle transport code EIRENE and a statistical model of plasma fluctuations. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.673499-05:
      DOI: 10.1002/ctpp.201410021
  • Long-Term Hydrogen Outgassing from Plasma Facing Components
    • Authors: J. Guterl; R. D. Smirnov, S. I. Krasheninnikov
      Pages: 415 - 420
      Abstract: The time evolution of hydrogen outgassing fluxes from plasma facing components (PFCs) in tokamaks at room temperature is investigated using a diffusion-reaction model with a single trap in the bulk of PFCs material. The release of hydrogen is surface-limited or diffusion-limited depending on properties of material and surface processes. In both surface and diffusion-limited regimes, the long-term decrease of the hydrogen outgassing flux follows a time power-law ∼t–κ, for which κ depends on the concentration of hydrogen in the material and on surface desorption processes. In surface-limited regime, reaction-diffusion models of hydrogen outgassing from wall material(with hydrogen diffusion in the material bulk) are shown to be equivalent to models of outgassing from wall surfaces. Experimental results showing power-law decays of hydrogen outgassing fluxes from PFCs during long off-plasma events (κ = 0.7 for graphite and κ = 0.8 for ITER-like JET configuration) can be then reproduced using a diffusion-reaction model in surface-limited regime. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.09702-05:0
      DOI: 10.1002/ctpp.201410034
  • Systematic Study of Tungsten Impurity Transport in Representative Regimes
           of Divertor Plasma
    • Authors: S. Yamoto; K. Hoshino, M. Toma, Y. Homma, A. Hatayama, X. Bonnin, D. Coster, R. Schneider
      Pages: 421 - 425
      Abstract: The tungsten impurity transport has been studied by IMPGYRO code for a model tokamak geometry of JT-60U tungsten experiments. The background plasma profiles calculated from SOLPS has been used. The density profiles of tungsten are compared between the low background deuterium density (Case A: n D + = 2.0 × 1019 m–3 at core side boundary) and the high background deuterium density (Case B: n D + = 3.0 × 1019 m–3 at core side boundary). In both cases, flow reversal in the SOL has been observed. The impurity density profile in the SOL is more localized for Case B. These features are possibly explained by the force balance between the thermal force and the friction force. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.851136-05:
      DOI: 10.1002/ctpp.201410031
  • Recent Improvements in the EMC3-Eirene Code
    • Authors: Y. Feng; H. Frerichs, M. Kobayashi, A. Bader, F. Effenberg, D. Harting, H. Hoelbe, J. Huang, G. Kawamura, J. D. Lore, T. Lunt, D. Reiter, O. Schmitz, D. Sharma
      Pages: 426 - 431
      Abstract: The EMC3-Eirene code is improved in many aspects. Ad hoc boundary conditions for intrinsic impurities at the SOL-core interface are removed by implicitly coupling to a 1D core model. Non-uniform cross-field transport coefficients are allowed in the new code version. A particle splitting technique is implemented for improving the Monte Carlo statistic in low-temperature ranges of most interest. Domain splitting, which was possible for the toroidal direction only, is now feasible for all three directions, facilitating mesh optimization for any specific divertor configuration. Stellarator-specific constraints on mesh construction have been relaxed. Axisymmetric neutral-facing components have been moved to cylindrical coordinates. All these features have improved the code performance and capability significantly. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.676835-05:
      DOI: 10.1002/ctpp.201410092
  • Investigation of Edge and SOL Particle Flux Patterns in High Density
           Regimes using SOLEDGE2D-EIRENE Code
    • Authors: G. Ciraolo; H. Bufferand, Ph. Ghendrih, P. Tamain, J. Bucalossi, Y. Marandet, E. Serre
      Pages: 432 - 436
      Abstract: We present numerical simulations of plasma transport obtained with the SOLEDGE2D code coupled to the EIRENE Montecarlo code for neutrals. We consider a double null magnetic configuration in a WEST geometry. Density and temperatures parallel profiles in the SOL domain are presented as well as Mach profile. We detail how using the penalization technique we are able to model plasma transport up to the first wall having access to energy and particle fluxes on the entire chamber wall. Moreover, we present the computed 2D contour map of the plasma mach number and of the magnitude of the ionisation source term in the whole poloidal section, emphasizing how complex and realistic geometries can be handled thanks to the penalization technique. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.394121-05:
      DOI: 10.1002/ctpp.201410018
  • First EMC3-EIRENE Simulations with Divertor Legs of LHD in Realistic
           Device Geometry
    • Authors: G. Kawamura; Y. Feng, M. Kobayashi, M. Shoji, T. Morisaki, S. Masuzaki, Y. Tomita
      Pages: 437 - 441
      Abstract: An extended mesh system for EMC3-EIRENE has been developed to simulate peripheral plasma including the ergodic and the divertor leg regions of LHD. Both the open and the closed divertor configurations are available. A series of simulations for 8MW input power, five different electron densities at the LCFS (last closed flux surface) and the open/closed configurations were carried out. Approximately 10 times larger neutral pressure was observed under the dome structure compared with the open configuration, which is in good agreement with experimental measurements. In the case of the closed configuration, the leg regions have a large contribution of ionization to hydrogen recycling. In the case of high density discharges, however, electron temperature in the legs becomes low and the major contribution of ionization moves to the ergodic region. Significant influence of configurations is observed in the inboard side of LHD, where closed divertor components are installed but little influence is seen near the LCFS. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.163201-05:
      DOI: 10.1002/ctpp.201410027
  • Integrated Modelling of Nitrogen Seeded JET ILW Discharges for H-mode and
           Hybrid Scenarios
    • Authors: I. Ivanova-Stanik; R. Zagórski, G. Telesca, A. Czarnecka, C. Challis, J. Hobirk, JET EFDA contributors
      Pages: 442 - 447
      Abstract: In this paper numerical simulations with COREDIV code of JET discharges with ITER-like wall are presented. We concentrate on the JET H-mode and hybrid scenarios with nitrogen seeding and all simulations have been performed with the same transport model and only the discharge input parameters like auxiliary heating Paux, line average plasma density nline, confinement factor H98, nitrogen input flux ΓpuffN were changed in the calcu lations. The separatrix density nsepe is an input parameter in our model and has been kept equal to 0.4÷0.5nlinein the simulations, with the recycling coefficient adjusted accordingly. It has been shown that COREDIV is able to reproduce basic parameters of nitrogen seeded discharges for both H-mode and hybrid scenarios. We have achieved reasonable agreement with global plasma parameters like radiations levels, Zeff and tungsten concentrations and the plasma profiles, including density, temperature and radiation are in very good agreement with experimental data. The agreement of the code results with the experimental data might be even better, if the simulations are further tuned taking into account uncertainties to the sputtering model, separatrix density or SOL transport. Simulations show that the observed Zeff level is defined mostly by the low Z impurity content, Be and N2 in the considered shots. It has been found that the tungsten radiation plays always very important role and can not be mitigated even by strong influx of nitrogen. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:42.088309-05:
      DOI: 10.1002/ctpp.201410024
  • Modelling the Effect of the Super-X Divertor in MAST Upgrade on Transition
           to Detachment and Distribution of Volumetric Power Losses
    • Authors: E. Havlíčková; M. Wischmeier, G. Fishpool
      Pages: 448 - 453
      Abstract: A density scan is performed in SOLPS5.0 for two divertor configurations of MAST Upgrade: (i) a short divertor silimiar to configurations in present-day tokamaks, (ii) the Super-X divertor. In the simulation, a clear roll-over of the ion flux and plasma density at the target is observed as the plasma detaches. The separatrix density at which the transition occurs is estimated. In addition, we investigate the ability of the long-legged divertor to reduce the target power loads and enhance the radiated power at higher collisionalities. We also study how distribution of power losses in the divertor region changes with the modification of geometry and we separately analyze neutral radiation and carbon ion line radiation. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.082013-05:
      DOI: 10.1002/ctpp.201410025
  • Multi-Fluid Transport Modeling of NSTX Upgrade Standard and Snowflake
           Divertor Configurations
    • Authors: E. T. Meier; V. A. Soukhanovskii, S. Gerhardt, J. E. Menard, T. D. Rognlien
      Pages: 454 - 458
      Abstract: In NSTX Upgrade (NSTX-U), power exhaust is expected to challenge available material and heat removal technologies, which are limited to ∼10 MW/m2. Preliminary analysis of heat flux mitigation strategies, including the snowflake divertor configuration and radiative divertor operation, is performed with the multi-fluid edge transport code, UEDGE. Divertor recycling between 95% and 99%, and power exhaust between 7 and 9 MW are explored. Compared to the standard divertor, the particular snowflake divertor studied here strongly reduces outer target heat flux, but tends to have higher (>10 MW/m2) inner target heat flux. This suggests that snowflake divertor optimization should be pursued in future work. Both neon and argon impurity seeding scenarios mitigate high heat fluxes in both standard and snowflake configurations, but argon can cause radiative collapse of the core plasma at only 3% concentration. Divertor cryopumping is also considered, and modeling shows ∼50% more particle removal with the snowflake divertor. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.262716-05:
      DOI: 10.1002/ctpp.201410055
  • Preliminary Comparison of the Conventional and Quasi-Snowflake Divertor
           Configurations with the 2D Code EDGE2D/EIRENE in the FAST Tokamak
    • Authors: B. Viola; G. Corrigan, D. Harting, G. Maddaluno, M. Mattia, V. Pericoli Ridolfini, R. Zagórski
      Pages: 459 - 463
      Abstract: The new magnetic configurations for tokamak divertors, snowflake and super-X, proposed to mitigate the problem of the power exhaust in reactors have clearly evidenced the need for an accurate and reliable modeling of the physics governing the interaction with the plates. The initial effort undertaken jointly by ENEA and IPPLM has been focused to exploit a simple and versatile modeling tool, namely the 2D TECXY code, to obtain preliminary comparison between the conventional and snowflake configurations for the proposed new device FAST that should realize an edge plasma with properties quite close to those of a reactor. The very interesting features found for the snowflake, namely a power load mitigation much larger than expected directly from the change of the magnetic topology, has further pushed us to check these results with the more sophisticated computational tool EDGE2D coupled with the neutral code module EIRENE. After a preparatory work that has been carried out in order to adapt this code combination to deal with non-conventional, single null equilibria and in particular with second order nulls in the poloidal field generated in the snowflake configuration, in this paper we describe the first activity to compare these codes and discuss the first results obtained for FAST. The outcome of these EDGE2D runs is in qualitative agreement with those of TECXY, confirming the potential benefit obtainable from a snowflake configuration. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.573343-05:
      DOI: 10.1002/ctpp.201410053
  • TECXY Code Simulation of Snowflake Divertor Configuration in DEMO Reactor
    • Authors: G. Pełka; R. Zagórski, V.P. Ridolfini, G. Artaserse, G. Calabrò, F. Crisanti, G. Maddaluno, G. Ramogida, B. Viola
      Pages: 464 - 468
      Abstract: Preliminary TECXY code simulation results of scrape-off layer conditions in DEMO1 reactor design are presented. The values for snowflake (SF) and single null divertor configurations are discussed. The SF divertor configuration used here, although not fully optimised yet, already promises better performance than standard single null divertor as far as heat load mitigation due to interactions with neutrals. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.2517-05:00
      DOI: 10.1002/ctpp.201410086
  • Investigation of Oscillations in the Plasma Sheath
    • Authors: D. Brida; D. Tskhakaya
      Pages: 469 - 473
      Abstract: In this work different plasma oscillation modes in the plasma sheath (PS) have been identified. For this pur-pose an electron-deuterium plasma under different conditions was considered. The plasma was simulated with the fully kinetic massively parallel Particle-in-Cell/Monte Carlo code BIT1 [1]. In order to exclude possible artificial boundary effects we simulated a sufficiently large area (10 - 50 cm), so that the PS in the simulation develops fully self-consistently. Our simulations show that each point in the PS oscillates with a significantly broad frequency spectrum. The largest oscillation amplitudes have the waves which are in resonance with the local plasma frequency for unmagnetized, and with the upper and lower hybrid frequencies for magnetized plasmas. In addition each point exhibits oscillations at resonance frequencies corresponding to other points in the PS. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:34.406949-05:
      DOI: 10.1002/ctpp.201410038
  • Modified Power Transmission Factor of Tungsten in Plasmas with Hot
           Electron Component
    • Authors: S. Takamura; S. Ono, N. Ohno
      Pages: 474 - 478
      Abstract: Power transmission factors (PTF) through the sheath of helium plasmas with hot electron component against two kinds of tungsten wall, virgin as well as nanostructured one due to helium irradiation are studied theoretically and experimentally. In the present theory the ion-induced electron emission in addition to secondary electron emission is taken into account, contributing to the cooling of the wall. Some discussions on the comparison between the measurement and the modified PTF theory are given. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.30586-05:0
      DOI: 10.1002/ctpp.201410016
  • Guiding Center Orbit Following Calculation of Edge Particle and Heat
           Transport in Stochastic Magnetic Field
    • Authors: C.C. Chang; Y. Nishimura, C.Z. Cheng
      Pages: 479 - 483
      Abstract: Particle and heat transport in tokamak edge is investigated by guiding center orbit following calculation. The guiding center equation is solved for both electrons and ions in the presence of magnetic perturbation. It is suggested that the remnants of the magnetic islands play a role in characterizing the radial transport. The transport coefficient is estimated which also demonstrate local structure in the vicinity of magnetic islands. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:42.288943-05:
      DOI: 10.1002/ctpp.201410044
  • Pedestal Structure without and with 3D Fields
    • Authors: J. D. Callen
      Pages: 484 - 492
      Abstract: Achieving high pedestal pressures in H(high)-mode plasmas confined in tokamaks is critical for obtaining fusion burning plasmas in ITER. Recent characterizations of quasi-equilibrium plasma parameter profiles in low collisionality H-mode pedestals in the DIII-D tokamak are briefly summarized. Critical plasma transport properties (large radial electron heat flow, density pinch) that establish the transport barrier structure of the pedestal profiles are identified. The paleoclassical transport model, which naturally includes a density pinch, is shown to provide the minimum electron heat and density transport in the pedestal. Microinstabilities can provide additional plasma transport within and especially at the top of pedestals. Macroscopic peeling-ballooning (P-B) instabilities cause periodic edge localized modes (ELMs) that limit the temporal and spatial growth of the pedestal initially and between ELMs. Externally imposed 3D resonant magnetic perturbations (RMPs) in the pedestal have been used to stabilize P-B modes and suppress ELMs. A magnetic flutter model of plasma transport induced by the 3D RMPs has been developed for low collisionality DIII-D pedestals. Comparisons of it with data on ELM suppression by RMPs indicate it can provide a “diffusivity hill” at the pedestal top that can impede pedestal growth and thereby stabilize P-B modes and suppress ELMs. Finally, transport equations for plasma density, electron and ion pressures and, most importantly, the plasma toroidal rotation frequency (and hence, via radial force balance, the radial electric field) in the presence of plasma transport due to collisional, paleoclassical, microturbulence-induced and 3D field effects are presented. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:35.627385-05:
      DOI: 10.1002/ctpp.201410010
  • Benchmarks of KIPP: Vlasov-Fokker-Planck Code for Parallel Plasma
           Transport in the SOL and Divertor
    • Authors: A. V. Chankin; D. P. Coster
      Pages: 493 - 497
      Abstract: Benchmarks of the new 1D2V kinetic code KIPP (KInetic code for Plasma Periphery) for parallel plasma transport in the scrape-off layer (SOL) and divertor of magnetic confinement fusion devices are presented. The code is based on the continuum discretisation scheme for the Vlasov-Fokker-Planck equation. It assumes plasma quasi-neutrality, maintained by the electron parallel momentum balance, and uses a logical sheath boundary condition for the Debye potential drop at material surfaces. The code is parallelized under the MPI environment, with the most time consuming part, Coulomb collisions, being calculated simultaneously for all spatial locations by separate processors using a sparse matrix solver for the full non-linear collision operator in two velocity variables: parallel and gyro-averaged perpendicular velocities. KIPP is being developed with the aim of integrating it into SOLPS (B2-Eirene), to replace fluid treatment of parallel plasma transport with the kinetic one. Benchmark results for parallel electron heat conduction and electron-ion thermoforce for highly collisional plasmas are presented, as well as some results for less collisional plasmas. This paper focuses on the 1d2v features of the code, with the 0d2v features presented earlier in [1, 2]. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.455396-05:
      DOI: 10.1002/ctpp.201410047
  • On Ion Sound Speed in a High Recycling Plasma Edge
    • Authors: T. Eisenstecken; D. Tskhakaya
      Pages: 498 - 502
      Abstract: The ion sound speed is derived from the propagation speed of small perturbations. For this purpose, we consider particle, momentum and energy conservation equations for the ions and Ohms law for the electrons. We find out that there exist three oscillation modes: two of them correspond to the waves propagating towards the wall and one propagating away from it. One of the modes propagating towards the wall and the mode propagating away from the wall are identified as sound waves. We demonstrate that for the plasma parameters corresponding to the high recycling regime the ion sound speed propagating towards the wall exceeds significantly the commonly given isothermal, or adiabatic sound speeds. Moreover, we show that there exists a layer in front of the wall, where the second mode propagating towards the wall has a positive growth rate. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:39.129711-05:
      DOI: 10.1002/ctpp.201410039
  • On the Electron Distribution Function in the Edge Plasma
    • Authors: M. Gasteiger; D. Tskhakaya
      Pages: 503 - 507
      Abstract: In this work we consider the electron kinetic equation and obtain electron velocity distributions and corresponding moments. This model represents a generalization of Chodura's [1] by inclusion of electron-electron and electron inelastic collisions. We find out that ee collisions in the edge plasma reduce the heat flux significantly and cannot be neglected. Contrary to this relatively weak inelastic collisions do not affect the electron heat flux. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.4491-05:00
      DOI: 10.1002/ctpp.201410048
  • Drifts, Currents, and Radial Electric Field in the Edge Plasma with Impact
           on Pedestal, Divertor Asymmetry and RMP Consequences
    • Authors: V. Rozhansky
      Pages: 508 - 516
      PubDate: 2014-06-20T08:26:34.58391-05:0
      DOI: 10.1002/ctpp.201410011
  • Progress with the COGENT Edge Kinetic Code: Implementing the Fokker-Planck
           Collision Operator
    • Authors: M. A. Dorf; R. H. Cohen, M. Dorr, J. Hittinger, T. D. Rognlien
      Pages: 517 - 523
      Abstract: COGENT is a continuum gyrokinetic code for edge plasma simulations being developed by the Edge Simulation Laboratory collaboration. The code is distinguished by application of a fourth-order finite-volume (conservative) discretization, and mapped multiblock grid technology to handle the geometric complexity of the tokamak edge. The distribution function F is discretized in v‖ – μ (parallel velocity – magnetic moment) velocity coordinates, and the code presently solves an axisymmetric full-f gyro-kinetic equation coupled to the long-wavelength limit of the gyro-Poisson equation. COGENT capabilities are extended by implementing the fully nonlinear Fokker-Plank operator to model Coulomb collisions in magnetized edge plasmas. The corresponding Rosenbluth potentials are computed by making use of a finite-difference scheme and multipole-expansion boundary conditions. Details of the numerical algorithms and results of the initial verification studies are discussed. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.592424-05:
      DOI: 10.1002/ctpp.201410023
  • Structure in the Edge Plasma Profiles in Tokamaks
    • Authors: W. M. Stacey
      Pages: 524 - 528
      Abstract: It is argued that the structure observed in radial profiles in the tokamak edge plasma is determined by the requirements of ion particle, momentum and energy conservation and the underlying transport mechanisms in the presence of sources and losses of particles, energy and momentum. The intent of this paper is to define a systematic formalism that can be employed for evaluating these transport coefficients from experimental inference and comparison with theory. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:38.529152-05:
      DOI: 10.1002/ctpp.201410019
  • Stochastic Processes Applied to the Spectroscopic Diagnostic of Hydrogen
           in Edge Plasmas
    • Authors: I. Hannachi; H. Capes, L. Godbert-Mouret, F. Guzman, M. Koubiti, Y. Marandet, J. Rosato, M.T. Meftah, R. Stamm
      Pages: 529 - 533
      Abstract: Stochastic processes may be used as an efficient model for the line shapes affected by Stark effect in edge plasma conditions. We check the accuracy of this approach on the Lyman γ line of hydrogen perturbed by ions only. We also use a stochastic process to investigate the effect of plasma oscillations on a line shape. Our model assumes that Langmuir waves are a sequence of oscillating electric fields changing their amplitude and phase according to an exponential waiting time distribution. The possible effects of Langmuir waves on the Lyman α Stark profile are discussed in edge plasma conditions. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:41.929573-05:
      DOI: 10.1002/ctpp.201410035
  • Radio Frequency Induced and Neoclassical Asymmetries and their Effects on
           Turbulent Impurity Transport in a Tokamak
    • Authors: I. Pusztai; M. Landreman, A. Mollén, Ye. O. Kazakov, T. Fülöp
      Pages: 534 - 542
      Abstract: Poloidal asymmetries in the impurity density can be generated by radio frequency heating in the core and by neoclassical effects in the edge of tokamak plasmas. In a pedestal case study, using global neoclassical simulations we find that finite orbit width effects can generate significant poloidal variation in the electrostatic potential, which varies on a small radial scale. Gyrokinetic modeling shows that these poloidal asymmetries can be strong enough to significantly modify turbulent impurity peaking. In the pedestal the E × B drift in the radial electric field can give a larger contribution to the poloidal motion of impurities than that of their parallel streaming. Under such circumstances we find that up-down asymmetries can also affect impurity peaking. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.841657-05:
      DOI: 10.1002/ctpp.201410012
  • Impact of a Langmuir Probe on Turbulence Measurements in the
           Scrape-Off-Layer of Tokamaks
    • Authors: C. Colin; P. Tamain, P. Ghendrih, F. Schwander, E. Serre
      Pages: 543 - 548
      Abstract: An issue for Langmuir probe measurements of SOL turbulence concerns the impact of the probe itself on plasma transport. The aim of this paper is to investigate this issue with a synthetic reconstruction of Langmuir probe measurements by inserting a synthetic probe into a 2D fluid SOL turbulence code. The effect of a biased probe is analysed as a function of its size. It is shown that the probe creates a transport barrier whose effect is non-local and affects the current's circulation in the plasma. The plasma density is depleted by the presence of the probe as well as the electrostatic potential. A strong impact on turbulence can also be observed. Such observations imply that the probed turbulence can differ significantly from the probe-free turbulence. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:39.580712-05:
      DOI: 10.1002/ctpp.201410087
  • Numerical Methods for 3D Tokamak Simulations Using a Flux-Surface
           Independent Grid
    • Authors: A. Stegmeir; D. Coster, O. Maj, K. Lackner
      Pages: 549 - 554
      Abstract: A numerical approach for 3D Tokamak simulations using a flux surface independent grid is presented. The grid consists of few poloidal planes with a Cartesian isotropic grid within each poloidal plane. Perpendicular operators can be discretised within a poloidal plane using standard second order finite difference methods. The discretisation of parallel operators is achieved with a field line following map and an interpolation. The application of the support operator method to the parallel diffusion operator conserves the self-adjointness of the operator on the discrete level and keeps the numerical decay rate at a low level. The developed numerical methods can be applied to geometries where an X-point is present. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:35.896889-05:
      DOI: 10.1002/ctpp.201410041
  • 3D Properties of Edge Turbulent Transport in Full-Torus Simulations and
           their Impact on Poloidal Asymmetries
    • Authors: P. Tamain; H. Bufferand, G. Ciraolo, C. Colin, Ph. Ghendrih, F. Schwander, E. Serre
      Pages: 555 - 559
      Abstract: The 3D fluid turbulence code TOKAM3X is used to investigate the 3D properties of edge turbulent transport and their impact on poloidal asymmetries. Simulations are run in circular limited plasmas in a domain covering both closed and open flux surfaces. Turbulence characteristics exhibit large inhomogeneities both in the radial and poloidal directions reminiscent of experimental observations. The low field side mid-plane in particular is found to be locally more fluctuating and intermittent than the rest of the Scrape-Off-Layer (SOL). As a consequence of this asymmetry, radial turbulent transport, that represents 80 to 90% of the total radial flux, is strongly ballooned, with 75% of the flux flowing through LFS. The equilibrium of the edge plasma is impacted by this asymmetry through the existence of large amplitude asymmetric parallel flows as well as through the development of poloidally asymmetric radial decay lengths making it impossible to define a single SOL width. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:39.73486-05:0
      DOI: 10.1002/ctpp.201410017
  • Impact of Differing Electron and Ion Temperatures on Emission Lines of
           Impurities in Tokamak Divertors
    • Authors: M. Koubiti; L. Godbert-Mouret, S. Ferri, Y. Marandet, J. Rosato, R. Stamm
      Pages: 560 - 564
      Abstract: In this paper we present some investigations of the broadening mechanisms affecting the emission line profiles of impurities present in the divertor regions of tokamaks. For that purpose, we have considered two visible lines (C IV n = 5-6 and n = 6-7) emitted by lithium-like carbon ions for which the contributions of the Zeeman, Stark and Doppler effects are examined. The paper is focused on the impact of differing electron and ion temperatures on the broadening and shapes of the C IV n = 6-7 line for conditions relevant to a detached tokamak divertor plasma. It is shown, that the C IV n = 6-7 line profile calculated with differing electron and ion temperatures may be significantly different from the one calculated with equal temperatures but the same density. This suggests that the electron density determination from the fit of the measured spectra of such a line may be inaccurate when using equal ion and electron temperatures instead of differing ones. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:39.900966-05:
      DOI: 10.1002/ctpp.201410046
  • Modeling of Stark-Broadened Lines in a Fluctuating Edge Plasma
    • Authors: J. Rosato; Y. Marandet, A. Peiffer, H. Capes, L. Godbert-Mouret, M. Koubiti, R. Stamm
      Pages: 565 - 569
      Abstract: A line shape model that accounts for low-frequency fluctuations is applied to the Balmer series of the hydrogen isotopes (atomic transitions n 2). The plasma fluid parameters (density, temperature, etc.) are described as random variables characterized by a prescribed joint probability density function. A special emphasis is devoted to Stark broadened lines, which are sensitive to the plasma density. It is shown that fluctuations can lead to a significant increase of the line width if the fluctuation level ΔNe/〈Ne〉 (with 〈Ne〉 and ΔNe being respectively the density averaged along the line-of-sight and its RMS value) is large. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:35.019777-05:
      DOI: 10.1002/ctpp.201410045
  • Stabiity of the Radiative Mode m = n = 0 and Density Limit in Tokamaks
    • Authors: D. Kh. Morozov; A. A. Mavrin
      Pages: 570 - 574
      Abstract: The problem of density limit and thermal disruption is one of the most important in ITER project. Different reasons for the disruption discuss now. At least 3% of disruptions are produced by the high level of impurity radiation from the edge [P.C. De Vries et al., Nucl. Fusion 51, 053018 (2011)]. Two reasons of the thermal disruption have been discussed earlier using simplified radiation model, the equilibrium loss [J.F. Drake, Phys. Fluids 30, 2429 (1987)], and radiation instability of the mode m = 0, n = 0 [M.Z. Tokar, Phys. Plasmas 7, 2432 (2000)]. Using the simplified model M.Z. Tokar founds two solutions. One of them is stable, the other is unstable. It is shown in the present paper that the unstable solution appears if the plasma density exceeds the critical value. The latter is found as a function of discharge parameters. It is shown also that the stable regime exists for realistic discharge parameters independently of plasma density. These regimes didn't investigated by M.Z. Tokar. Also, more adequate radiation models are discussed including charge-exchange. It is shown that the impurity - main plasma charge-exchange decreases the critical density. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.65268-05:0
      DOI: 10.1002/ctpp.201410090
  • Density and Temperature Correlations in the SOL; Implications for Gas Puff
           Imaging of Turbulence
    • Authors: D. Moulton; Y. Marandet, P. Tamain, Ph. Ghendrih, R. Futtersack
      Pages: 575 - 579
      Abstract: Using a two-dimensional turbulence model, a strong linear correlation is found between density and electron temperature within scrape-off layer fluctuations. This has important implications for gas puff image interpretation for two commonly used lines, Dα and HeI (587.6 nm). Dα emission responds approximately linearly to proportional changes in the underlying plasma density and electron temperature, making image interpretation relatively straightforward. However, above ∼25 eV, HeI (587.6 nm) emission is approximately constant with proportional changes in density and electron temperature, so underlying plasma perturbations may go unseen. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:34.831753-05:
      DOI: 10.1002/ctpp.201410089
  • Time Dependent Collisional-Radiative Model for Scrape-Off Layer Impurity
           Turbulent Transport Studies
    • Authors: F. Guzmán; Y. Marandet, D. Moulton, R. Futtersack, Ph. Ghendrih, R. Guirlet, J. Rosato, R. Stamm, P. Tamain
      Pages: 580 - 584
      Abstract: The effects of Scrape-off layer (SOL) turbulent fluctuations on the ionization/recombination source terms in the continuity equations for impurities are investigated. These effects come in addition to those related to turbulent transport, and could be important in the SOL owing to the large relative fluctuation levels measured there. Given the time scales involved, the ionization balance does not follow adiabatically fluctuations. In order to investigate these effects, we have developed a time dependent solver for the population kinetics of the full atomic system. A first calculation is performed for beryllium, using turbulent fields from the TOKAM2D non isothermal code. Turbulent fluctuations are shown to shift substantially the abundances of the different ionization stages via source averaging effects. A stochastic model, which could potentially be used to generate fluctuation averaged ionization/recombination rate coefficients, is then used to model the output of TOKAM2D. The results for abundances are compared to those of the population kinetics code. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:35.470133-05:
      DOI: 10.1002/ctpp.201410037
  • Conversion of Magnetic Energy of Runaway Electrons During Disruption
    • Authors: Yu. L. Igitkhanov
      Pages: 585 - 590
      Abstract: A substantial portion of poloidal magnetic energy stored in the RE beam could dissipate in the first wall (FW) armor due to ohmic dissipation of inductive current. Relatively small part of magnetic energy can also be converted into heat during a direct impact of the RE beam on the FW due to the ohmic dissipation of a return current, induced by penetration of the RE beam into a metal in the skin time scale. The observed increase of temperature at a spot on the JET dump plate upon increasing the RE current can be explained by assuming that 50 % of the RE energy, predominantly magnetic energy, is converted into heat. Calculations of the RE stopping power (SP) onto the ITER FW Be bulk armor predict strong erosion. While the threshold energy for beryllium melting is about 5 MJ/m2, the RE heat deposition is expected to be almost twice as large. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:37.774578-05:
      DOI: 10.1002/ctpp.201410020
  • Edge Radial Electric Field Formation after the L-H Transition on JT-60U
    • Authors: K. Kamiya; G. Matsunaga, M. Honda, N. Miyato, H. Urano, Y. Kamada, K. Ida, K. Itoh, the JT-60 team
      Pages: 591 - 598
      Abstract: Spatio-temporal measurements of the impurity ion temperature, density, and rotation profiles around the plasma edge region have been made in the JT-60U tokamak, allowing the determination of radial electric field, Er, with the key dimensionless parameter (poloidal Mach number, Upm) at the L-H transition in a number of operational regimes. We found that there is variation in the L-H transition in terms of its time-scale; not only “hard” type transition with a faster time-scale than that seen in the plasma transport (as represented by an energy confinement time, τE) as seen in the many conventional tokamaks, but also “soft” one with a slow time-scale (≈τE) is possible solution, including a complex multi-stage Er transition in the later H-phase. The most important point is that the critical condition for the L-H transition predicted by ion-orbit loss model could be applicable only for “hard” transition (occurred at Upm ≥ 1), and not necessary for “slow” one (occurred even at Upm < 1). Characteristics of the turbulent density fluctuation with the frequency range of 100 kHz at the plasma edge region, in addition to a uniform toroidal MHD oscillation (i.e., n = 0), during ELM-free H-phase are also reported. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:40.364372-05:
      DOI: 10.1002/ctpp.201410013
  • Integrated Simulation Study of ELM Pacing by Pellet Injection in ITER
    • Authors: N. Hayashi; N. Aiba, T. Takizuka, N. Oyama
      Pages: 599 - 604
      Abstract: Simulations with an integrated code TOPICS-IB showed that a small pellet can significantly reduce the ELM energy loss by penetrating deeply into the pedestal and triggering high-n ballooning modes localized near the pedestal top, with conditions; the injection from the low-field-side with a speed fast enough to approach the pedestal top when the pedestal pressure is about 95% of natural ELM onset. The effectiveness of the above suitable conditions of pellet injection for ELM pacing has been confirmed by JT-60U and then ITER simulations. The pellet particle content required for ELM pacing is larger for the pedestal plasma with higher density and farther from the stability boundary of ideal ballooning mode near the pedestal top. For an ITER standard scenario, the required pellet particle content is about a few % of pedestal particle content, which gives the physics background to the present design value. Simulations also showed that fueling pellets can be injected from the high-field-side just after ELM pacing pellets without disturbing the pacing. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:33.839474-05:
      DOI: 10.1002/ctpp.201410040
  • Simulation of Radiation Cooling Effects in the GAMMA 10 West End-Cell
           Using Fluid Model
    • Authors: H. Takeda; Y. Nakashima, Y. Iida, K. Hosoi, T. Furuta, M. Toma, A. Hatayama, K. Ichimura, H. Ueda, M. Iwamoto, Y. Hosoda, M. Yoshikawa, M. Sakamoto, M. Ichimura, T. Imai
      Pages: 605 - 609
      Abstract: We have started a simulation study of background plasma in the GAMMA 10 west end-cell using fluid-code in order to understand divertor simulation experiment. This fluid code is B2 code without including the effects of drifts and currents. In this paper, we obtained the effects of additional neutral particles density. As increasing amount of additional neutral particle density, ion and electron temperature decrease and plasma density builds up. Especially, the peak of plasma density moves from z = 10.04 m from z = 10.1 m. However, electron temperature does not decrease detachment front for high ion temperature. Therefore, it needs that ion temperature is decreased. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:33.999035-05:
      DOI: 10.1002/ctpp.201410036
  • Modeling of Hydrogen Retention and Outgassing from Co-Deposits with
           Distributed Energy States
    • Authors: R. D. Smirnov; S. I. Krasheninnikov, J. Guterl, M. J. Baldwin, R. P. Doerner
      Pages: 610 - 614
      Abstract: A hydrogen retention/outgassing model with distributed hydrogen energy states in material is proposed. The model considers hydrogen in co-deposits to occupy continuous energy states arising from all realizable local atomic arrangements in a medium with some degree of disorder. The outgassing flux of hydrogen from a sample is described via occupancy evolution of energy states corresponding to free hydrogen. We apply the model to analysis of hydrogen thermo-desorption experiments on beryllium co-deposits produced in a Be capable sputter magnetron system at the UCSD PISCES laboratory. It is demonstrated that the model can describe experimentally obtained time evolutions of hydrogen desorption flux from co-deposits in different thermal outgassing regimes. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:36.752913-05:
      DOI: 10.1002/ctpp.201410033
  • Modeling of Tungsten Dust Transport in ITER with Multi-Physics Code
    • Authors: A. Yu. Pigarov; R. D. Smirnov, S. I. Krasheninnikov, T. D. Rognlien
      Pages: 615 - 619
      Abstract: Self-consistent modeling of dust particle kinetics and multi-fluid multi-species transport of boundary plasmas in ITER is performed with the multi-physics code DUSTT/UEDGE. Results are presented for the sensitivity of the pedestal and divertor plasmas to the injection rate, size, and source location of the dust particles. The cases of low-z and high-z dust material injection are compared. The impact of dust ablation on impurity inventory, distribution of ions over ionization states, and electron plasma power losses is studied. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-06-20T08:26:35.182743-05:
      DOI: 10.1002/ctpp.201410088
  • Particle in Cell/Monte Carlo Collision Method for Simulation of RF Glow
           Discharges: Effect of Super Particle Weighting
    • Authors: E. Erden; I. Rafatov
      Pages: n/a - n/a
      Abstract: A parallel Particle in Cell/Monte Carlo Collision (PIC/MCC) numerical code for glow discharge plasma simulations is developed and verified. This method is based on simultaneous solution of the Lorentz equations of motion of super particles, coupled with the Poisson's equation for electric field. Collisions between the particles are modelled by the Monte Carlo method. Proper choice of particle weighting is critically important in order to perform adequate and efficient PIC simulations of plasma. Herein, effects of particle weighting on the simulations of capacitive radio‐frequency argon plasma discharges are studied in details. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2013-12-09T07:40:11.324107-05:
      DOI: 10.1002/ctpp.201300047
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