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Articles With Citations to Z. Abou-Assaleh

Theoretical Plasma Physics

Controlled Thermonuclear Fusion Energy

1994

Implementation of Non-local Transport Model into 2D Fluid Code

A.S.Kukushkin , A.M.Runov

Kurchatov Institute. Kurchatov sir. 46. 123182. Moscow. Russia

Contribution to Plasma Physics, 34 (1994)

". . .  The main idea of the present paper is to produce a rather simple and computationally   efficient   hybrid   approach,   where   the   two-dimensional   fluid equations  are  solved  in  order  to  find  the  plasma  parameters,  and  the  parallel heat  flows  appearing  in  these  equations  are  found  from  simplified  kinetic equations   allowing  one  to  take  into  account  the  effects   related   to  the long-ranging  hot  particles.  This  approach  is  similar  to  the  one  proposed  by Z.Abou-Assaleh et al.  (PET-3. Bad Honnef,  1992), but the usage of the Krook collision   operator,   which   is   much   simpler   than   the   exact   Fokker-Plank operator,  allows  us  to  produce  an  efficient  code  for  two-dimensional  modelling of the edge plasma.  ….."

"Absorption of intense microwaves and ion acoustic turbulence due to heat transport"

De Groot, J S, Liu, J M, and Matte, J P.

Lawrence Livermore National Lab., CA (United States)

United States: N. p., 1994.

Abstract

Measurements and calculations of the inverse bremsstrahlung absorption of intense microwaves are presented. The isotropic component of the electron distribution becomes flat-topped in agreement with detailed Fokker-Planck calculations. The plasma heating is reduced due to the flat-topped distributions in agreement with calculations. The calculations show that the heat flux at high microwave powers is very large, q{sub max} {approx} 0.3 n{sub e}v{sub e}T{sub e}. A new particle model to, calculate the heat transport inhibition due to ion acoustic turbulence in ICF plasmas is also presented. One-dimensional PIC calculations of ion acoustic turbulence excited due to heat transport are presented. The 2-D PIC code is presently being used to perform calculations of heat flux inhibition due to ion acoustic turbulence.

References

10.  J.H. Rogers, J. S. De Groot, Z. Abou-Assaleh, J. P. Matte, T. W. Johnston, andM. D. Rosen, "Electron Heat Transport in a Steep Temperature Gradient," Physics of Fluids B 1, 741 (1989)

Phys. Plasmas 1 (11), November 1994 (3570)

Physics of Plasmas -- November 1994 -- Volume 1, Issue 11, pp. 3570-3576

"Electron heat transport with non-Maxwellian distributions"

J. M. Liu and J. S. De Groot

Plasma Research Group, Department of Applied Science, University of California, Davis, California 95616

J. P. Matte and T. W. Johnston

INRS-Énergie et Matériaux, C.P. 1020, Varennes, Québec, J3X 1S2 Canada

R. P. Drake

Plasma Physics Research Institute, Lawrence Livermore National Laboratory, L-418, P.O. Box 808, Livermore, California 94551

(Received 8 March 1994; accepted 14 July 1994)

Abstract

Measurements are presented of electron heat transport with non-Maxwellian (flattopped) distributions due to inverse bremsstrahlung absorption of intense microwaves in the University of California at Davis Aurora II device [Rogers et al., Phys. Fluids B 1, 741 (1989)]. The plasma is created by pulsed discharge in a cylindrical vacuum chamber with surface magnets arranged to create a density gradient. The ionization fraction (~1%) is high enough that charged particle collisions are strongly dominant in the afterglow plasma. A short microwave pulse (~2 µs) heats a region of the afterglow plasma (n_e/n_cr0.5) creating a steep axial (L_T~1–10_ei) temperature gradient. Langmuir probes are used to measure the relaxation of the heat front after the microwave pulse. Time and space resolved measurements show that the isotropic component of the electron velocity distribution is flat topped (~exp[–(v/v_m)^m], m2) in agreement with Fokker–Planck calculations using the measured density profile. Classical heat transport theory is not valid both because the isotropic component of the electron velocity distribution is flattopped and the temperature gradients are very steep. Physics of Plasmas is copyrighted by The American Institute of Physics.

Electron heat transport with non-Maxwellian distributions

Electron heat transport with non-Maxwellian distributions

Phys. Rev. Lett. 73, 2055–2058 (1994)

"Measurements of Radial Heat Wave Propagation in Laser-Produced Exploding-Foil Plasmas"

D. S. Montgomery¹, O. L. Landen^1,3, R. P. Drake^2,3, K. G. Estabrook¹, H. A. Baldis¹, S. H. Batha², K. S. Bradley³, and R. J. Procassini¹

¹Lawrence Livermore National Laboratory, Livermore, California 94551

²Plasma Physics Research Institute, University of California Davis and Lawrence Livermore National Laboratory, Livermore, California 94551

³Department of Applied Science, University of California Davis, Davis, California 95616

Abstract

Time-resolved, 2D images of x-ray emission from thin, laser-irradiated titanium foils are presented. The foils are irradiated with 0.35 µm light at intensities of 1 x 10¹⁵ W/cm² which produces a plasma with electron densities <= 10²² cm^-3 and electron temperature of 3-4 keV. X-ray emission that is characteristic of the thermal heat front is observed to propagate radially outward from the heated region. Comparison of these measurements with 2D hydrodynamic simulations of the experiment suggests the radial heat flux to be about 3% of the free-streaming heat flux.

©1994 The American Physical Society

URL: http://link.aps.org/abstract/PRL/v73/p2055

Phys. Rev. Lett. 73, 2055 (1994) Montgomery et al. - Measurements of Radial Heat...

Measurements of radial heat wave propagation in laser-produced exploding-foil plasmas

Phys. Rev. A 50, 2691–2700 (1994)

"Electron distribution function in a thin plasma layer and possible x-ray laser emission due to a sharp temperature gradient"

Boris N. Chichkov, Yoshiaki Kato, Hartmut Ruhl, and Sergey A. Uryupin

Theoretical Quantum Electronics, Technical University Darmstadt, Hochschulstrasse 4A, Darmstadt, Germany

Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565, Japan

P. N. Lebedev Physics Institute, Leninsky prospect 53, Moscow, Russia

Abstract

The temporal evolutions of the electron distribution function and the electric field in a dense, hot, multiply charged plasma due to the presence of a sharp temperature gradient from one side (plasma–cold matter contact) and a sharp density gradient from the other side (plasma-vacuum boundary) are studied. The prospects for x-ray lasing in such a plasma are discussed. The analogy with a p-n junction semiconductor laser is emphasized.

©1994 The American Physical Society

URL: http://link.aps.org/abstract/PRA/v50/p2691

Phys. Rev. A 50, 2691 (1994) Chichkov et al. -

Phys. Rev. Lett. 72, 2717–2720 (1994)

"Measurements of inverse bremsstrahlung absorption and non-Maxwellian electron velocity distributions"

J. M. Liu, J. S. De Groot, J. P. Matte, T. W. Johnston, and R. P. Drake

Plasma Research Group, Department of Applied Science, University of California, Davis, California 95616

Institut National de la Recherche Scientifique Energie et Matériaux, C.P. 1020, Varennes, Québec, Canada J3X 1S2

Plasma Physics Research Institute, Lawrence Livermore National Laboratory, L-418, P.O. Box 808, Livermore, California 94551
 

Abstract

Non-Maxwellian (flattopped) electron velocity distributions resulting from inverse bremsstrahlung of intense microwaves are measured directly for the first time in experiments performed on the UCD AURORA II device. The experiments are performed in the afterglow of a pulsed discharge plasma that is moderately collisional and sufficiently ionized (~1%) that Coulomb collisions are dominant. Langmuir probe measurements indicate that the isotropic component of the electron velocity distribution is non-Maxwellian in very good agreement with electron kinetic (Fokker-Planck) simulations.

©1994 The American Physical Society

URL: http://link.aps.org/abstract/PRL/v72/p2717
DOI: 10.1103/PhysRevLett.72.2717
PACS: 52.50.Gj, 52.25.-b, 52.50.Jm, 52.65.+z

Phys. Rev. Lett. 72, 2717 (1994) Liu et al. - Measurements of inverse bremsstrahlung...

Measurements of inverse bremsstrahlung absorption and non-Maxwellian electron velocity distributions

"Measurements of inverse bremsstrahlung absorption and non-axwellian electron velocity distributions"

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