Z. Abou-Assaleh, Ph.D.

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 Zouhier Abou-Assaleh, Ph.D.

Theoretical Plasma Physics

 & Controlled Thermonuclear Fusion Energy

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with Citations To Z. Abou-Assaleh
 
 

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 2008
 
http://www.iop.org/EJ/abstract/0963-0252/17/1/015012

Ion acoustic wave studies near the presheath/sheath boundary in a weakly collisional argon/xenon plasma

Lutfi Oksuz et al 2008 Plasma Sources Sci. Technol. 17 015012 (5pp)   doi:10.1088/0963-0252/17/1/015012

Lutfi Oksuz1, Dongsoo Lee and Noah Hershkowitz
Department of Engineering Physics, University of Wisconsin at Madison, Madison, WI 53706, USA
1 Present address: Department of Physics, Suleyman Demirel University, Isparta 32260, Turkey.
E-mail: oksuz@fef.sdu.edu.tr

Abstract:

Ion acoustic wave (IAW) phase velocities are measured near the sheath/presheath boundary in a weakly collisional argon/xenon plasma. Wave profiles versus position are measured using a boxcar averager with a gate width of 30 ns and CW excitation at 50 or 75 kHz. Variable gate delays allow measurement of details of the wave close to the boundary. It is shown that the phase velocity at the presheath/sheath boundary is approximately twice the phase velocity in the bulk plasma for both argon and argon/xenon plasmas, in agreement with a recent calculation (Lee D et al 2007 Phys. Rev. Lett. 99 155004). This result indicates each ion's drift velocity at the boundary is equal to the IAW phase velocity in the bulk plasma.

Print publication: Issue 1 (February 2008)
Received 28 August 2007, in final form 11 October 2007
Published 19 December 2007

 
 
 2006
 
Thin Solid Films
Volumes 506-507, 26 May 2006, Pages 674-678
The Joint Meeting of 7th APCPST (Asia Pacific Conference on Plasma Science and Technology) and 17th SPSM (Symposium on Plasma Science for Materials) - 7th APCPST/17th SPSM
 
Ion flow and sheath physics studies in multiple ion species plasmas using diode laser based laser-induced fluorescence
 
G.D. Severn1, a, Corresponding Author Contact Information, E-mail The Corresponding Author, Xu Wangb, Eunsuk Kob, N. Hershkowitzb, M.M. Turnerc and R. McWilliamsd
aDepartment of Physics, University of San Diego, San Diego, CA 92110, USA
bEngineering Physics Department, University of Wisconsin-Madison, Madison, WI 53706, USA
cNational Center for Plasma Science and Technology, Dublin City University, Glasnevin, Dublin 9, Ireland
dDepartment of Physics and Astronomy, University of California, Irvine, CA 92049, USA

 
 
Abstract:

Diode lasers have proved to be a valuable light source for laser-induced fluorescence (LIF) measurements for plasma science since the early 1990s, and they have recently improved the state of the art of measuring ion flow from ion velocity distribution functions (ivdfs) at the sheath–presheath boundary in single and multiple ion species plasmas. In the case of a low temperature two ion species plasma (ArI + HeI), we were the first to show experimentally that ion species may reach the sheath edge flowing at a very different speed than that expected from the single species Bohm Criterion (ArII ions exceed the individual Bohm flow speed by almost a factor of 2 at the sheath edge). Simulation results are found to agree. Diode laser technology relevant to LIF measurements in multiple ion species plasmas is discussed with the aim of addressing outstanding problems in sheath formation in such plasmas.

Keywords: Plasma sheath; Plasma diagnostics; Plasma spectroscopy
 


Corresponding Author Contact InformationCorresponding author.
1 Work supported by DOE grant no.DE-FG02-03ER54728, and NSF grant no. CHE0321326.
 
Thin Solid Films
Volumes 506-507, 26 May 2006, Pages 674-678
The Joint Meeting of 7th APCPST (Asia Pacific Conference on Plasma Science and Technology) and 17th SPSM (Symposium on Plasma Science for Materials) - 7th APCPST/17th SPSM
 
 2006
 

Contrib. Plasma Phys. 46, No. 1-2, 3 – 191 (2006) / DOI 10.1002/ctpp.200610001

Plasma Edge Physics with B2-Eirene

R. Schneider∗1, X. Bonnin2, K. Borrass3, D. P. Coster3, H. Kastelewicz4, D. Reiter5, V. A. Rozhansky6, and B. J. Braams7

1 Max-Planck-Institut f¨ur Plasmaphysik, EURATOMAssociation, Teilinstitut Greifswald,Wendelsteinstr.1, D-17491 Greifswald, Germany

2 LIMHP, CNRS-UPR 1311, Universit´e Paris XIII, 99, avenue JB Cl´ement, F-93430 Villetaneuse, France

3 Max-Planck-Institut f¨ur Plasmaphysik, EURATOMAssociation, Boltzmannstraße 2, D-85748 Garching, Germany

4 Max-Planck-Institut f¨ur Plasmaphysik, EURATOMAssociation, Mohrenstraße 41, D-10117 Berlin, Germany

5 Institut f¨ur Plasmaphysik, Forschungszentrum J¨ulich, Trilateral Euregio Cluster, D-52425 J¨ulich, Germany

6 Saint-Petersburg State Polytechnical University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia

7 Emory University, Mathematics and Science Center, 400 Dowman Drive, Atlanta, Georgia 30322, USA

Received 8 March 2005, accepted 18 September 2005

Published online 25 Januar 2006

Key words Plasma edge, plasma modelling, plasma codes, plasma transport boundary layer.

PACS 52.27.Lw, 52.65.Rr, 52.50.Qt

The B2-Eirene code package was developed to give better insight into the physics in the scrape-off layer (SOL), which is defined as the region of open field-lines intersecting walls. The SOL is characterised by the competition of parallel and perpendicular transport defining by this a 2D system. The description of the plasma-wall interaction due to the existence of walls and atomic processes are necessary ingredients for an understanding of the scrape-off layer. This paper concentrates on understanding the basic physics by combining the results of the code with experiments and analytical models or estimates. This work will mainly focus on divertor tokamaks, but most of the arguments and principles can be easily adapted also to other concepts like island divertors in stellarators or limiter devices.

The paper presents the basic equations for the plasma transport and the basic models for the neutral transport. This defines the basic ingredients for the SOLPS (Scrape-Off Layer Plasma Simulator) code package. A first level of understanding is approached for pure hydrogenic plasmas based both on simple models and simulations with B2-Eirene neglecting drifts and currents. The influence of neutral transport on the different operation regimes is here the main topic. This will finish with time-dependent phenomena for the pure plasma, so-called Edge Localised Modes (ELMs). Then, the influence of impurities on the SOL plasma is discussed. For the understanding of impurity physics in the SOL one needs a rather complex combination of different aspects. The impurity production process has to be understood, then the effects of impurities in terms of radiation losses have to be included and finally impurity transport is necessary. This will be introduced with rising complexity starting with simple estimates, analysing then the detailed parallel force balance and the flow pattern of impurities. Using this, impurity compression and radiation instabilities will be studied. This part ends, combining all the elements introduced before, with specific, detailed results from different machines. Then, the effect of drifts and currents is introduced and their consequences presented. Finally, some work on deriving scaling laws for the anomalous turbulent transport based on automatic edge transport code fitting procedures will be described.

 
 2006
 

Japanese Journal of Applied Physics
Vol. 45, No. 7, 2006, pp. 5945-5950
URL :
http://jjap.ipap.jp/link?JJAP/45/5945/
DOI : 10.1143/JJAP.45.5945

Determination of Plasma Flow Velocity by Mach Probe and Triple Probe with Correction by Laser-Induced Fluorescence in Unmagnetized Plasmas

Yong-Sup Choi*, Hyun-Jong Woo, Kyu-Sun Chung**, Myoung-Jae Lee, David Zimmerman1 and Roger McWilliams1

Electric Probe Applications Laboratory (ePAL), Hanyang University, Seoul 133-791, Korea
1Department of Physics and Astronomy, University of California, Irvine, CA 92697, U.S.A.

(Received March 16, 2005; revised September 19, 2005; accepted February 23, 2006; published online July 7, 2006)

Abstract:

Plasma flow velocity was measured by Mach probe (MP) and laser-induced fluorescence (LIF) methods in unmagnetized plasmas with supersonic ion beams. Since the ion gyro-radius was much larger than the probe radius, unmagnetized Mach probe theory was used to determine plasma flow in argon RF plasma with a weak magnetic field (<200 G). In order to determine flow velocities, the Mach probe is calibrated via LIF in the absence of the ion beam, where existing probe theories may be valid although they use different geometries (sphere and plane) and analyzing tools [particle-in-cell (PIC) and kinetic models]. For the comparison of the average plasma flow velocities by MP and LIF, the supersonic ion beam velocity was measured by LIF and then incorporated into a simple formula for average plasma velocity with provisions for background plasma density and beam-corrected electron temperature (Te) measured by a triple probe.

Keywords:

plasma flow velocity, Mach probe, triple probe, laser induced fluorescence, LIF, unmagnetized plasma.


*Present address: Production Engineering Center, Samsung SDI Co., Ltd., Suwon, Gyeonggi 575, Korea.
**Corresponding author: E-mail address: kschung@hanyang.ac.kr

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References:

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 2005
 
Journal of Nuclear Materials
Volumes 337-339 , 1 March 2005, Pages 246-250
 
Modification of atomic physics rates due to nonlocal electron parallel heat transport in divertor plasmas

F. Allaisa, Corresponding Author Contact Information, J.P. Mattea, Corresponding Author Contact Information, E-mail The Corresponding Author, F. Alouani-Bibia, C.G. Kima, D.P. Stotlerb and T.D. Rognlienc

aINRS-Énergie, Matériaux et Télécommunications, 1650 boul. Lionel Boulet, Varennes, Québec, Canada J3X 1S2
bPrinceton Plasma Physics Laboratory, Princeton, NJ, USA
cLawrence Livermore National Laboratory, Livermore, CA, USA
 

Abstract:

The effect of steep temperature gradients on the rate of ionization of atomic hydrogen is studied numerically with the electron kinetic code ‘FPI’ [Phys. Rev. Lett. 72 (1994) 1208]. A set of cross sections [‘Atomic and Plasma-Material Interaction data for fusion’. Supplement to the journal Nucl. Fusion 4 (1993)] has been used which gives the same rates of radiation, ionization and recombination as in the well known edge modeling codes ‘UEDGE’ and ‘DEGAS’ for Maxwellian electron energy distribution functions. For this purpose, 30 energy levels are included in the computation, as stepwise ionization is dominant. The enhancement of the ionization rate by non-Maxwellian effects in the colder part of the plasma is significant.

Keywords: Collisional radiative model; Divertor modelling; Kinetics effects; Parallel transport; UEDGE

 

 
 2005
 
doi:10.1016/j.tsf.2005.08.114 
Thin Solid Films
Volumes 506-507 , 26 May 2006, Pages 674-678

The Joint Meeting of 7th APCPST (Asia Pacific Conference on Plasma Science and Technology) and 17th SPSM (Symposium on Plasma Science for Materials) - 7th APCPST/17th SPSM
 
Ion flow and sheath physics studies in multiple ion species plasmas using diode laser based laser-induced fluorescence
G.D. Severn1, a,, Xu Wangb, Eunsuk Kob, N. Hershkowitzb, M.M. Turnerc and R. McWilliamsd

aDepartment of Physics, University of San Diego, San Diego, CA 92110, USA
bEngineering Physics Department, University of Wisconsin-Madison, Madison, WI 53706, USA
cNational Center for Plasma Science and Technology, Dublin City University, Glasnevin, Dublin 9, Ireland
dDepartment of Physics and Astronomy, University of California, Irvine, CA 92049, USA
Available online 27 December 2005.
 

Abstract

Diode lasers have proved to be a valuable light source for laser-induced fluorescence (LIF) measurements for plasma science since the early 1990s, and they have recently improved the state of the art of measuring ion flow from ion velocity distribution functions (ivdfs) at the sheath–presheath boundary in single and multiple ion species plasmas. In the case of a low temperature two ion species plasma (ArI + HeI), we were the first to show experimentally that ion species may reach the sheath edge flowing at a very different speed than that expected from the single species Bohm Criterion (ArII ions exceed the individual Bohm flow speed by almost a factor of 2 at the sheath edge). Simulation results are found to agree. Diode laser technology relevant to LIF measurements in multiple ion species plasmas is discussed with the aim of addressing outstanding problems in sheath formation in such plasmas.

 
 
 2005
 
Parallel heat flux limits in the tokamak scrape-off layer

W Fundamenski 2005 Plasma Phys. Control. Fusion 47 R163-R208   doi:10.1088/0741-3335/47/11/R01

W Fundamenski
Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, UK

Abstract. It is well known that the classical Spitzer–Harm–Braginskii expression for the parallel plasma heat flux breaks down in the long mean free path limit, relevant to many practical applications, most crucially power exhaust via the tokamak scrape-off layer (SOL). This problem is usually addressed by limiting the heat flux to some fraction of the free streaming value, with constants of proportionality ασ, where σ ∈ {e,i}, ranging from 0.03 to 3. The following paper presents a brief overview of the problem, compares the results of various kinetic studies, suggests the optimal values of ασ for use in plasma–fluid codes, and examines the impact of these values on 2D SOL simulations using the EDGE2D transport code. In this context, gyro-kinetic parallel heat flux expressions for both electrons and ions are derived from the generalized transport equations—an improved version of Grad's 21-moment approach—and their implications to tokamak modelling are discussed.

Print publication: Issue 11 (November 2005)
Received 6 December 2004, in final form 28 July 2005
Published 5 October 2005

http://www.iop.org/EJ/abstract/0741-3335/47/11/R01/

http://ej.iop.org/links/rTqyxnIWm/SnTZP6Wg2xGkAZxsav5vpA/psst5_1_022.pdf

 
 2005

Scrape-off layer physics: an introduction (to be published)

Ralf Schneider,

Max-Planck-Institut f¨ur Plasmaphysik, EURATOM association, Garching, Germany

http://www.ipp-garching.mpg.de/~dpc/rfs.pdf

 
 2005
 
Phys. Plasmas 12, 063104 (2005) (8 pages)
Supersonic propagation of ionization waves in an underdense, laser-produced plasma
C. Constantin, C. A. Back, K. B. Fournier, G. Gregori, O. L. Landen, S. H. Glenzer, and E. L. Dewald
Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550
M. C. Miller
Los Alamos National Laboratory, Los Alamos, New Mexico 87545

(Received 11 November 2004; accepted 8 April 2005; published online 6 June 2005)

A laser-driven supersonic ionization wave propagating through a millimeter-scale plasma of subcritical density up to 2–3  keV electron temperatures was observed. Propagation velocities initially ten times the sound speed were measured by means of time-resolved x-ray imaging diagnostics. The measured ionization wave trajectory is modeled analytically and by a two-dimensional radiation-hydrodynamics code. The comparison to the modeling suggests that nonlocal heat transport effects may contribute to the attenuation of the heat-wave propagation. ©2005 American Institute of Physics

 
 2005
 

L Oksuz et al 2005 Plasma Sources Sci. Technol. 14 201-208

Plasma, presheath, collisional sheath and collisionless sheath potential profiles in weakly ionized, weakly collisional plasma

L Oksuz1 and N Hershkowitz
Department of Engineering Physics, University of Wisconsin-Madison, USA

1 Current address: Plasma Research Laboratory, Dublin City University, Dublin, Republic of Ireland.

Received 30 September 2003
Published 7 February 2005

Print publication: Issue 1 (February 2005)

Abstract. Potential variations in bulk plasma, presheath and sheath describe the plasma potential profile responsible for ion acceleration out of weakly ionized, weakly collisional plasma. Experiments with emissive probes, Langmuir probes, laser induced fluorescence (LIF) and Mach probes in a multi-dipole plasma show that the presheath potential near a negatively biased plate scales as {- e\phi}/ {T_{\rm e}} = \sqrt {{( {x_0 - x})}/ \lambda } and is insensitive to the value of the plate bias. Plasma parameters were chosen so that ε = λDap 0.02 → 0.06 and 0.2 < λ/L <0.6, where λ is the ion–neutral mean free path, λD is the Debye length and L is the plasma length. A Child–Langmuir-like sheath with width scaling as λD(ephgr/Te)3/4 with a TeD initial boundary electric field has been measured. A transition region, in which the plasma starts to deviate from being quasi-neutral, is observed between the presheath and the Child–Langmuir sheath. The transition region is approximately 2λD or λ1/5λd4/5. Mach probe data, calibrated by LIF data, suggest that the average ion velocity reaches the Bohm velocity inside the transition region and significantly exceeds the Bohm velocity at the Child–Langmuir sheath/transition boundary.

doi:10.1088/0963-0252/14/1/022
URL: http://stacks.iop.org/0963-0252/14/201
PII: S0963-0252(05)93759-6
 

http://ej.iop.org/links/q38/g,zrlJAHsg6q,iou3NUz1w/psst5_1_022.pdf
 
 2005
 
Presheath Environment in Weakly Ionized Single and Multispecies ...
[14] S. L. Gulick, B. L. Stansfield, Z. Abouassaleh, C. Boucher, J. P. Matte,.
T. W. Johnston, and R. Marchand, “Measurement of pre-sheath flow ve- ...
ieeexplore.ieee.org/iel5/27/30693/ 01420601.pdf?arnumber=1420601
 
Presheath environment in weakly ionized single and multispecies plasmas
Hershkowitz, N.   Ko, E.   Xu Wang   Hala, A.M.A.  
Center for Plasma-Aided Manuf., Univ. of Wisconsin, Madison, WI, USA;
 

This paper appears in: Plasma Science, IEEE Transactions on
Publication Date: April 2005
Volume: 33,  Issue: 2, Part 2
On page(s): 631- 636
ISSN: 0093-3813
INSPEC Accession Number: 8398049
Digital Object Identifier: 10.1109/TPS.2005.844608
Posted online: 2005-04-18 09:10:46.0
 

Abstract
The presheath located near boundaries in weakly ionized plasmas is a rich environment in which charge exchange, and ion-ion streaming instabilities combine to establish the electric fields that accelerate ions to close to the Bohm velocity at the sheath/presheath boundary. Charge exchange sets the presheath scale length in weakly collisional plasma, in which ionization can be neglected. The transition of mobility limited ion flow near the bulk plasma to free fall motion close to the plate for single species plasmas is explored. Measurements in argon-helium multidipole plasmas of plasma potential with emissive probes and ion energy distribution functions with laser induced fluorescence are presented. These data show that the argon ions are speeded up by the presheath electric fields, argon ions are heated, and ion-ion instability is present as ions approach the boundary.
 
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=1420601&isnumber=30693
  
 
 
 2004
Phys. Rev. Lett. 92, 205006 (2004)
Effect of Nonlocal Transport on Heat-Wave Propagation
G. Gregori, S. H. Glenzer, J. Knight, C. Niemann, D. Price, D. H. Froula, M. J. Edwards, and R. P. J. Town
Lawrence Livermore National Laboratory, University of California, P.O. Box 808, California 94551, USA
A. Brantov and W. Rozmus
Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1
V. Yu. Bychenkov
P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 117924, Russia

We present the first direct measurements of spatially and temporally resolved temperature and density profiles produced by nonlocal transport in a laser plasma. Absolutely calibrated measurements have been performed by Rayleigh scattering and by resolving the ion-acoustic wave spectra across the plasma volume with Thomson scattering. We find that the electron temperature and density profiles disagree with flux-limited models, but are consistent with nonlocal transport modeling. ©2004 The American Physical Society

 

Effect of Nonlocal Transport on Heat-Wave Propagation
URL: http://link.aps.org/abstract/PRL/v92/e205006
 
 
 2004
 
Contributions to Plasma Physics

Volume 44, Issue 4 , Pages 352 - 360

Published Online: 8 Jun 2004

Copyright © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

H. Kastelewicz, G. Fussmann *
Humboldt-Universität zu Berlin, Institut für Physik Experimentelle Plasmaphysik, Germany

*Correspondence to G. Fussmann, Humboldt-Universität zu Berlin, Institut für Physik Experimentelle Plasmaphysik, Germany

Abstract
Deuterium discharges in the PSI device have been modelled using the coupled package of the B2 hydrodynamic plasma code and the Eirene Monte-Carlo neutral code. Radial and axial plasma profiles have been calculated for different magnetic field configurations, various radial diffusion laws and for different values of the flux limiter in the parallel electron heat conduction law used in the B2 code. The results are compared with experimental findings. The axial variation of the magnetic field strength is found to have an important influence on the plasma state via the axial plasma flow which closely resembles the neutral gas streaming through a series of laval nozzles. For particular magnetic field configurations, an appropriate ansatz for the parallel electron heat conduction turns out to be a crucial point for the applicability of hydrodynamic models to linear devices like the plasma generator PSI. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Received: 5 September 2003; Accepted: 5 April 2004
 2004

Physica Scripta. Vol. T108, 7–13, 2004

Simulation of the Edge Plasma in Tokamaks

D. P. Coster1, X. Bonnin2, B. Braams3, D. Reiter4, R. Schneider2 and the ASDEX Upgrade Team

1 Max-Planck-Institut fu¨ r Plasmaphysik, EURATOM Association, Garching, Germany

2 Max-Planck-Institut fu¨ r Plasmaphysik, EURATOM Association, Greifswald, Germany

3 Courant Institute, New York University, New York, NY, USA

4 Institut fu¨ r Plasmaphysik, FZ Ju¨ lich, EURATOM Association, Ju¨ lich, Germany

Abstract

Edge plasma modelling is discussed with particular emphasis on the comparison of a fluid neutral model with a kinetic neutral model. By iterative inclusion of additional effects, the agreement between the two is improved. Of particular importance is the proper treatment of neutrals at the core boundary, the proper implementation of a neutral flux limit, and the modification of the ion heat boundary condition to include the neutral contribution. In the end, the agreement in the upstream profiles of electron and ion temperatures, and of electron and neutral core densities is very satisfactory. In addition, the effects of parallel ion and electron heat flux limiters, of transport ballooning to the low field side, and of drifts are investigated.

 

http://www.ipp.mpg.de/~dpc/ibmtok1/dpc/hinm_paper_2003.pdf
Physica Scripta Online Vol. T108,? 7,? 2004

Simulation of the Edge Plasma in Tokamaks

D. P.? Coster, Max-Planck-Institut f?smaphysik,? EURATOM Association,? Garching,? Germany.
X.? Bonnin, Max-Planck-Institut f?smaphysik,? EURATOM Association,? Greifswald,? Germany.
B.? Braams, Courant Institute,? New York University,? New York,? USA.
D.? Reiter, Institut f?smaphysik, FZ J?? EURATOM Association,? J?? Germany.
R.? Schneider, Max-Planck-Institut f?smaphysik,? EURATOM Association,? Greifswald,? Germany.
ASDEX Upgrade Team? ,

 

Received? June 26, 2003; accepted?August 7, 2003.
 

Simulation of the Edge Plasma in Tokamaks

 
 2003
 
Contributions to Plasma Physics, 43, No. 7, 426 (2003)
Laser plasma plume kinetic spectroscopy of the nitrogen and carbon species (Contributions to Plasma Physics 43 No. 7, 426 (2003))
Z. Zelinger *, M. Novotný 2, J. Bulí 2, J. Lanok 2, P. Kubát 1, M. Jelínek 2
1J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejkova 3, 18223 Prague 8, Czech Republic
2Institute of Physics, Acad. of Sciences of the Czech Republic, Na Slovance 2, 18221 Prague 3, Czech Republic
 
 2002
 
http://epsppd.epfl.ch/Montreux/pdf/P3_215.pdf
F.Allais, J.P. Matte, F.Alouani-Bibi, and D.Stotler,
29th EPS Conference on Plasma Phys. and Contr. Fusion Montreux, 17-21 June 2002 ECA Vol. 26B, P-3.215 (2002)
"Nonlocal Electron Parallel Heat Transport in Divertor Plasmas and Atomic Physics Rates"
 
 2001
Physics of Plasmas -- May 2001 -- Volume 8, Issue 5, pp. 1650-1658
Electron kinetic simulations of solid density Al plasmas produced by intense subpicosecond laser pulses. I. Ionization dynamics in 30 femtosecond pulses
S. Ethier and J. P. Matte
INRS-Énergie et Matériaux, 1650 Boul. Lionel-Boulet, Varennes, Québec, Canada, J3X 1S2

(Received 29 September 2000; accepted 29 January 2001)

The interaction of a 1018 W/cm2, 30 fs laser pulse with solid Al was simulated with the electron kinetic code "FPI" [J. P. Matte et al., Phys. Rev. Lett. 72, 1208 (1994)] in which an improved average ion module was fully coupled to the electron kinetics. It includes electron impact ionization and excitation and their inverse processes: collisional recombination and de-excitation; as well as radiative decay and pressure ionization. We compare to runs without the inverse processes, and also without atomic physics (with <Z> set to 11). Atomic physics strongly affects the energy balance and the shape of the distribution function. Line radiation is mostly due to three body recombination into excited states after the peak of the pulse, as the plasma cools down. Despite the atomic processes and the high density, strongly non-Maxwellian distribution functions were obtained due to very steep temperature gradients and strong collisional heating, at the peak of the pulse. However, after the pulse, there is a very rapid thermalization of the electron distribution to which inverse processes strongly contribute. ©2001 American Institute of Physics.

Electron kinetic simulations of solid density Al plasmas produced by intense subpicosecond laser pulses. I. Ionization dynamics in 30 femtosecond pulses
 
 2001
 
Jean-Pierre Matte
MODELING NON-LOCAL PARALLEL ELECTRON HEAT TRANSPORT IN DIVERTOR PLASMAS
Presentation at the NSTX Research Forum 2001
Princeton Plasma Physics Laboratory January15-18, 2001
 
http://nstx.pppl.gov/f.../ET5_Matte_.pdf
 1998
 
A. S. Margellos, M.Sc. thesis, Faculty of Commerce and Administration, Concordia University, 1998. “THE CONDITIONAL CAMP AND THE CROSS SECTION OF EXPECTED RETRNS: EVIDENCE FOR THE CANADIAN MARKET”
"….  ACKNOWLEDGEMENTS  . . . to thank Dr. Zouhier A. Assaleh for his computer assistance …”.  Note: Assistance in the Data and Numerical Calculations.
 1997
 
C S Pitcher and P C Stangeby 1997 Plasma Phys. Control. Fusion 39 779-930
REVIEW ARTICLE
Experimental divertor physics

C S Pitcher and P C Stangeby
Max-Planck-Institut für Plasmaphysik, Garching bei München, Germany

Experimental divertor physics
Institute of Physics Online Archive
http://gita.grainger.uiuc.edu/IOPText/0741-3335/39/6/001/p706r1.pdf
 
 1997
 
Kinetic effects in tokamak scrape-off layer plasmas
O. V. Batishchev, S. I. Krasheninnikov, Peter J. Catto, A. A. Batishcheva, D. J. Sigmar,  X. Q. Xu, J. A. Byers, T. D. Rognlien, R. H. Cohen, M. M. Shoucri, I. P. Shkarofskii4)
1674 Phys. Plasmas, Vol. 4, No. 5, May 1997
http://adsabs.harvard.edu/abs/1997PhPl....4.1672B
 1996
Vincent A. Mousseau, Ph.D. dissertation. Idaho National Engineering Laboratory. Lockheed Martin Idaho Technologies. INEL-96/0149, May 1996 .
"Fully Implicit Kinetic Modelling of Collisional Plasma"
http://www.osti.gov/bridge/servlets/purl/239296-SYCkrq/webviewable/239296.pdf

 

 1996
 
Physica Scripta, Vol. 54, p.627 12/1996
Self-similar electron distributions in a non-uniform plasma embedded in a high-frequency electromagnetic field
Ferrante, G.; Porshnev, P. I.; Uryupin, S. A.; Zarcone, M.
Self-similar electron distributions in a non-uniform plasma embedded in a high-frequency electromagnetic field
 1996
Astrophysical Journal v.462, p.1005 05/1996 (ApJ Homepage)
Nonlocal Heat Transport in the Solar Wind
Canullo, M. V.; Costa, A.; Ferro-Fontan, C.
Abstract
 
1996ApJ...462.1005C Page 1005
Nonlocal Heat Transport in the Solar Wind
 1996
Journal of the Optical Society of America B: Optical Physics, Volume 13, Issue 2, February 1996, pp.447-453
Application of x-ray-laser interferometry to study high-density laser-produced plasmas
Wan, A. S.; da Silva, L. B.; Barbee, T. W., Jr.; Cauble, R.; Celliers, P.; Libby, S. B.; London, R. A.; Moreno, J. C.; Trebes, J. E.; Weber, F.
Lawrence Livermore National Laboratory, Livermore, California 94550
 
Application of x-ray-laser interferometry to study high-density laser-produced plasmas
Abstract Application of x-ray-laser interferometry to study high-density laser-produced plasmas
 1995

W Arter 1995 Rep. Prog. Phys. 58 1-59

Numerical simulation of magnetic fusion plasmas

W Arter
Culham Lab., AEA Technol., Abingdon, UK

Print publication: Issue 1 (January 1995)

Abstract. The review specializes to the modelling of plasmas in a particular type of fusion experiment, namely the tokamak. Simulation is taken to imply the use of a model which involves variation in at least two coordinate directions and is nonlinear, the nonlinearity invariably being of the advective type. Developments in the period 1976-1992 are covered under five main headings, with particle methods constituting the first. The remaining four concern the solution via mesh-based methods of (1) the Fokker-Planck equation, (2) drift-wave problems, (3) edge models and (4) time-dependent magnetohydrodynamic problems. Care is taken to outline the capabilities of the currently available software. Progress in the. Design of numerical algorithms for the mesh-based simulations is found to have been incremental rather than revolutionary. In particle simulation, gyrokinetic schemes and the ' delta f' method have been found to give dramatic gains in some circumstances. Many of the newer results obtained withstand comparison with experimental observation, although it has not always proved possible to reach the extreme conditions found in tokamaks, especially when three-dimensional effects are important.

doi:10.1088/0034-4885/58/1/001
URL: http://stacks.iop.org/0034-4885/58/1

 
http://www.iop.org/EJ/abstract/0034-4885/58/1/001/
Numerical simulation of magnetic fusion plasma
Institute of Physics Online Archive
W Arter
AEA Technology, Culham. Abingdon. Oxon OX14 3DB, UK
Rep. Prog. Phys. 58 (1995) 1-59. Primed in the UK
0034-4885/95/010001+59S59.50  © 1995 IOP Publishing Ltd
". . .

     Lastly, it is worth noting that Fokker-Planck codes have been written to model inertial confinement fusion experiments, e.g. Andrade et al (1981), and at least one such (FPl) has then been used to model tokamak edge plasmas (Abou-Assaleh et al 1990).  The computational details are not directly relevant to this review, but the physical results from FPl are interesting, since they suggest that the heat transport is not well modelled by corresponding fluid codes. A comparison with results obtained using particle methods (section 3.6) would be of interest.

. . ."

 
 1995
 
Physics of Plasmas -- August 1995 -- Volume 2, Issue 8, pp. 3100-3105
Self-similar electron distribution, inverse bremsstrahlung, and heat flux inhibition in high-Z nonuniform plasmas
S. A. Uryupin, S. Kato, and K. Mima
Institute of Laser Engineering, Osaka University, Suita, Osaka 565, Japan

(Received 23 June 1994; accepted 12 April 1995)

The self-similar distribution of electrons is found for a nonuniform underdense plasma that is heated by an intensive laser field. The distribution function is flat-topped for the low-energy electrons. And in the high-energy region, it has a well-pronounced high-energy tail. It is also found how the electron heat flux and the absorption coefficient depend upon both the ratios of electron mean-free path to the inhomogeneity scale of effective temperature and of the oscillation velocity to the thermal velocity. The actual shapes of electron energy distribution, the heat flux limitation, and the electromagnetic radiation absorption rate are given, both for a currentless plasma and for a plasma with a finite electric current. ©1995 American Institute of Physics.

 

Self-similar electron distribution, inverse bremsstrahlung, and heat flux inhibition in high-Z nonuniform plasmas
Self-similar electron distribution, inverse bremsstrahlung, and heat flux inhibition in high-Z nonuniform plasmas
 1995
Physics of Plasmas -- May 1995 -- Volume 2, Issue 5, pp. 1412-1420
Modeling and effects of nonlocal electron heat flow in planar shock waves
F. Vidal and J. P. Matte
Institut National de la Recherche Scientifique—Energie et Matériaux, 1650 Montée Ste. Julie, CP 1020, Varennes, Québec J3X 1S2, Canada
M. Casanova and O. Larroche
Commissariat à l'Energie Atomique, Centre d'Etudes de Limeil-Valenton, 94195 Villeneuve St. Georges Cedex, France

(Received 7 November 1994; accepted 4 January 1995)

Electron heat flow was computed in the context of a steadily propagating shock wave. Two problems were studied: a Mach 8 shock in hydrogen, simulated with an ion kinetic code, and a Mach 5 shock in lithium, simulated with an Eulerian hydrodynamic code. The electron heat flow was calculated with Spitzer–Härm classical conductivity, with and without a flux limit, and several nonlocal electron heat flow formulas published in the literature. To evaluate these, the shock's density, velocity, and ion temperature profiles were fixed, and the electron temperature and heat flow were compared to those computed by an electron kinetic code. There were quantitative differences between the electron temperature profiles calculated with the various formulas. For the Mach 8 shock in hydrogen, the best agreement with the kinetic simulation was obtained with the Epperlein–Short delocalization formula [Phys. Fluids B 4, 2211 and 4190 (1992)], and the Luciani–Mora–Bendib formula [Phys. Rev. Lett. 55, 2421 (1985)] gave good agreement. For the Mach 5 shock in lithium, both of these gave good agreement. The earlier Luciani–Mora–Virmont formula [Phys. Rev. Lett. 51, 1664 (1983)] gave fair agreement, while that of San Martin et al. [Phys. Fluids B 4, 3579 (1992); 5, 1485 (1993)] was even further off than the classical Spitzer–Härm [Phys. Rev. 89, 977 (1953)] formula for thermal conduction. To assess the effect of nonlocal electron heat flow on the shock's hydrodynamics and ion kinetics, each of the two problems was done with two different electron heat flow models: the classical Spitzer–Härm local heat conductivity, and the Epperlein–Short nonlocal electron heat-flow formula. In spite of the somewhat different electron temperature profiles, the effect on the shock dynamics was not important. ©1995 American Institute of Physics.

 

Modeling and effects of nonlocal electron heat flow in planar shock waves
Modeling and effects of nonlocal electron heat flow in planar shock waves
 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.  ….."
 
 
 1994
 
J. M. Liu, J. S. De Groot, J. P. Matte and T. W. Johnston and R. P. Drake
Phys. Plasmas 1 (11), November 1994 (3570)
"Electron heat transport with non-Maxwellian distributions"
 
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)

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 (ne/ncr<=0.5) creating a steep axial (LT~1–10lambdaei) 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/vm)m], m>~2) 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
 1994
 
Phys. Rev. Lett. 73, 2055–2058 (1994)
Measurements of Radial Heat Wave Propagation in Laser-Produced Exploding-Foil Plasmas.
D. S. Montgomery1, O. L. Landen1,3, R. P. Drake2,3, 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
 

Received 31 August 1992

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
 1994
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
 

Received 8 February 1994

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. - Electron distribution function in...
Electron distribution function in a thin plasma layer and possible x-ray laser emission due to a sharp temperature gradient
 1994
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
 

Received 15 December 1993

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"
 
 1993
David Peter Coster, Ph.D. dissertation. PRINCETON UNIVERSITY, 1993 .
"Tokamak divertor modeling with fluid and kinetic codes. "
 
http://www.ipp-garching.mpg.de/~dpc/thesis_single/thesis_single.html
References
Other approaches
[PDF] Tokamak divertor modeling with fluid and kinetic codes.
 
 1993
Physics of Fluids B: Plasma Physics -- May 1993 -- Volume 5, Issue 5, pp. 1453-1470
Kinetic theory of a nonequilibrium plasma: Evaluation of the vectorized collisional Boltzmann equation
Ann W. Morgenthaler and Peter L. Hagelstein
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 38-280, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139

(Received 22 June 1992; accepted 15 January 1993)

Cartesian velocity moments of the Boltzmann equation are evaluated using modal solutions to the spherical harmonic oscillator as a basis set. The nonlinear collision matrix describing the interaction between any two modes is evaluated analytically for the Landau collision operator, and matrix elements describing collisions between identical particles are calculated for some pairs of azimuthally symmetric modes. First-order linear transport coefficients calculated directly from collision matrix elements are shown to agree exactly with previously published results; coefficients of thermal conductivity and viscosity are computed much more accurately by trivially extending this calculation. Relaxation times for self-collisions in a two-dimensional linearized plasma are also computed, indicating that the plasma equilibrates in roughly one to ten times the Spitzer self-collision time. The results obtained in this paper are useful for both analytic and numerical simulations of nonequilibrium plasmas and an explicit six-moment model for a one-component azimuthally symmetric plasma is given. Physics of Fluids B: Plasma Physics is copyrighted by The American Institute of Physics.

 

Kinetic theory of a nonequilibrium plasma - Evaluation of the vectorized collisional Boltzmann equation
Kinetic theory of a nonequilibrium plasma - Evaluation of the vectorized collisional Boltzmann equation
Kinetic theory of a nonequilibrium plasma Evaluation of the vectorized collisional Boltzmann equation
 1992
 
Sidney Luther Gulick, Ph.D. dissertation. Université du Québec, Institut National de la recherche Scientifique, (INRS - Énergie et Matériaux), Varennes, Québec, Canada, 1992.
"UNE MESURE DE LA FONCTION DE DISTRIBUTION DE VITESSES IONIQUES DANS LA PREGAINE D'UN PLASMA PAR LA FLUORESCENCE INDUITE PAR LASER"
 
 1992

J A Meyer et al 1992 Plasma Sources Sci. Technol. 1 147-150

Measurements of the presheath in an electron cyclotron resonance etching device

J A Meyer, G -H Kim, M J Goeckner and N Hershkowitz
Eng. Res. Center for Plasma-Aided Manuf., Wisconsin Univ., Madison, WI, USA

Print publication: Issue 3 (August 1992)

Abstract. The first direct measurement of a collisional Bohm presheath from plasma potential measurements is given. By measuring the presheath thickness in front of a grounded wafer stage, a determination of the collision mean free path for ions in an electron cyclotron resonance etching tool has been made. Presheaths were measured in N2 and CF4 plasma using an emissive probe. The presheath thickness in N2 was found to be linearly dependent on the mean free path. Measurements of CF4 plasmas, for which the collision cross sections are unknown, have shown results similar to those found for nitrogen. This result has enabled an extrapolation to be made of the effective cross section for collisions in plasmas created from CF4.

doi:10.1088/0963-0252/1/3/001
URL: http://stacks.iop.org/0963-0252/1/147

http://www.utdallas.edu/~goeckner/publications/PSST1p147_1992.pdf
 
 
 1992
http://www.fluidmal.uma.es/pdfs/PFB_1992.pdf
Physics of Fluids B: Plasma Physics -- November 1992 -- Volume 4, Issue 11, pp. 3579-3585
Self-consistent, nonlocal electron heat flux at arbitrary ion charge number
Juan R. Sanmartín and J. Ramírez
E.T.S.I. Aeronáuticos, Universidad Politécnica, 28040 Madrid, Spain
R. Fernández-Feria
E.T.S.I. Industriales, Universidad de Sevilla, 41012 Sevilla, Spain
F. Minotti
Laboratorio de Física del Plasma, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina

A single, nonlocal expression for the electron heat flux, which closely reproduces known results at high and low ion charge number Z, and ``exact'' results for the local limit at all Z, is derived by solving the kinetic equation in a narrow, tail-energy range. The solution involves asymptotic expansions of Bessel functions of large argument, and (Z-dependent) order above or below it, corresponding to the possible parabolic or hyperbolic character of the kinetic equation; velocity space diffusion in self-scattering is treated similarly to isotropic thermalization of tail energies in large Z analyses. The scale length H characterizing nonlocal effects varies with Z, suggesting an equal dependence of any ad hoc flux limiter. The model is valid for all H above the mean-free path for thermal electrons. Physics of Fluids B: Plasma Physics is copyrighted by The American Institute of Physics.

 

Self-consistent, nonlocal electron heat flux at arbitrary ion charge number
Self-consistent, nonlocal electron heat flux at arbitrary ion charge number
 1992
 
Review of Scientific Instruments -- January 1992 -- Volume 63, Issue 1, pp. 31-36
Validating cylindrical Langmuir probe techniques
J. H. Rogers, J. S. De Groot, and D. Q. Hwang
University of California Davis and Lawrence Livermore National Laboratory, L-794 Livermore, California 94550

Several methods for estimating the plasma potential and density using cylindrical Langmuir probes are compared to the self-consistent solutions of the Vlasov–Poisson equations calculated by Laframboise (J. G. Laframboise, Ph. D. dissertation, University of Toronto, 1966). Measurements are made during the decay of a magnetic-field-free plasma in which the mean-free path of the electron is shorter than the dimensions of the vacuum vessel (the electrons, therefore, have a Maxwellian velocity distribution). The measurements are made in a parameter range in which exact analytical solutions do not exist for the ion and electron saturation currents, 0.5<=R/lambdaDe<=5, where R is the probe radius and lambdaDe is the electron Debye length (kTe/4pine2)1/2. An iterative procedure is used to fit the data at probe voltages both above and below the plasma potential while constraining the curves to be continuous at the plasma potential. The measured curves could be represented extremely well by the numerical results. It is therefore assumed that the plasma parameters used to fit the numerical results to the measurements are correct. The systematic errors which result from using several analysis techniques which assume R/lambdaDe<<1 are also presented, and it is shown that empirical corrections to these errors can be described which compensate for the finite probe radius. Review of Scientific Instruments is copyrighted by The American Institute of Physics.

 

Validating cylindrical Langmuir probe techniques
Validating cylindrical Langmuir probe techniques
 1991
Present state of research into the interaction between powerful laser radiation and high-temperature plasmas
V T Tikhonchuk
Physics-Uspekhi, Volume 34(1991), Number 10, Pages 903-909
 
 1991
 
Applied Physics Letters -- July 29, 1991 -- Volume 59, Issue 5, pp. 534-536
Measurement of energy penetration depth of subpicosecond laser energy into solid density matter
A. Zigler, P. G. Burkhalter, and D. J. Nagel
Naval Research Laboratory, Washington, DC 20375
M. D. Rosen
Lawrence Livermore Laboratory, Livermore, California 94550
K. Boyer, G. Gibson, T. S. Luk, A. McPherson, and C. K. Rhodes
University of Illinois at Chicago, P. O. Box 4348, Chicago, Illinois 60680

The energy penetration depth characteristic of the interaction of intense subpicosecond (~600 fs) ultraviolet (248 nm) laser radiation with solid density material has been experimentally determined. This was accomplished by using a series of ultraviolet transmitting targets consisting of a fused silica (SiO2) substrate coated with an 80–600 nm layer of MgF2. The measurement of He-like and H-like Si and Mg lines, as a function of MgF2 thickness, enabled the determination of the energy penetration depth. It was found that this depth falls in the range of 250–300 nm for a laser intensity of ~3×1016 W/cm2. Based on numerical simulations, it is estimated that solid density material to a depth of ~250 nm is heated to an electron temperature of ~500 eV.

Applied Physics Letters is copyrighted by The American Institute of Physics.

 

Measurement of energy penetration depth of subpicosecond laser energy into solid density matter
Measurement of energy penetration depth of subpicosecond laser energy into solid density matter
 1991
Physics of Fluids B: Plasma Physics -- February 1991 -- Volume 3, Issue 2, pp. 485-491
Non-Maxwellian electron distributions in ionizing plasmas
R. Marchand, J. P. Matte, and K. Parbhakar
INRS-ENERGIE, CP 1020, Varennes, Quebec J3X 1S2, Canada

Electron kinetics is considered in a plasma in which the distribution of ion charge stages is far from the coronal equilibrium. In rapidly ionizing plasmas, radiative cooling and ionization are found to cause the electron distribution to deviate significantly from a Maxwellian. The relevance of such distribution functions to divertor plasmas near the neutralizer plate is discussed. Physics of Fluids B: Plasma Physics is copyrighted by The American Institute of Physics

 

Non-Maxwellian electron distributions in ionizing plasmas
Non-Maxwellian electron distributions in ionizing plasmas
Reference Query Results for 1991PhFlB...3..485M
 1991

Октябрь 1991 г. Том 161, № 10

УСПЕХИ ФИЗИЧЕСКИХ НАУК

ИЗ ТЕКУЩЕЙ ЛИТЕРАТУРЫ

533.9

СОВРЕМЕННОЕ СОСТОЯНИЕ ИССЛЕДОВАНИЙ

ПО ФИЗИКЕ ВЗАИМОДЕЙСТВИЯ

МОЩНОГО ЛАЗЕРНОГО ИЗЛУЧЕНИЯ

С ВЫСОКОТЕМПЕРАТУРНОЙ ПЛАЗМОЙ

В. Т. Тихончук

(Физический институт им. П.Н. Лебедева АН СССР)

http://data.ufn.ru//ufn91/ufn91_10/129.pdf

 

 1990
Physics of Fluids B: Plasma Physics -- October 1990 -- Volume 2, Issue 10, pp. 2448-2455
Plasma evolution from laser-driven gold disks. II. Computational design and analysis
D. Ress and L. J. Suter
Lawrence Livermore National Laboratory, P. O. Box 808, L-473, Livermore, California 94550
E. F. Gabl and B. H. Failor
KMS Fusion, Inc., 700 KMS Place, P. O. Box 1567, Ann Arbor, Michigan 48106

The lasnex computer code [Comments Plasma Phys. Controlled Fusion 2, 51 (1975)] was used in the design and analysis of an experimental study of laser-driven plasma blowoff from gold disks. In the study, several temporal profiles of 0.53 mm laser illumination were used, including square pulses, picket pulse trains, and pulses with graduated leading edges. Preliminary modeling suggested diagnostic techniques [time- and space-resolved imaging of M-band x-ray emission and time- and space-averaged measurements of high-energy (3.5–20 keV) x-ray spectra] that complemented diagnostics already used in such experiments (four-frame holographic imaging to determine the electron-density profile in the underdense corona plasma). In this article, the lasnex results are analyzed and are compared with the measured plasma electron-density profiles and with time- and space-averaged measurements of the corona temperature. The simulation tracks the observed electron-density profiles fairly well during the early portions of the laser drive, during which the spatial profiles are approximately self-similar, but overestimates the electron density in the later, steady-state segment of the profile. For the corona electron temperature, simulation and experiment agree to within the experimental accuracy of ±20%. Physics of Fluids B: Plasma Physics is copyrighted by The American Institute of Physics.

 

Plasma evolution from laser-driven gold disks. II. Computational design and analysis
Plasma evolution from laser-driven gold disks. II. Computational design and analysis
 
 1990
Physics of Fluids B: Plasma Physics -- August 1990 -- Volume 2, Issue 8, pp. 1725-1728
Nonlocal heat transport in plasmas down steep temperature gradients
F. Minotti and C. Ferro Fontán
Laboratorio de F ísica del Plasma, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, 1428 Buenos Aires, Argentina

(

An analytic solution to the problem of nonlocal heat transport in plasmas by electrons whose range is not short compared to the temperature scale length is presented. The formalism extends the results of Albritton et al. [Phys. Rev. Lett. 57, 1887 (1986)] to an arbitrary ionization state Z. This simple transport scheme is checked against recent experiments in the AURORA device [Phys. Fluids B 1, 741 (1989)]. The agreement, both for the measured cold electron temperature profile and the plasma potential, is very good and comparable to the result of full kinetic calculations. Physics of Fluids B: Plasma Physics is copyrighted by The American Institute of Physics.

 

Nonlocal heat transport in plasmas down steep temperature gradients
Nonlocal heat transport in plasmas down steep temperature gradients
 1990
F. Minotti and C. Ferro Fontan
Phys. Fluids B 2 (8) August 1990 (1725)
"Nonlocal heat transport in plasmas down steep temperature gradients"
 1987
 
J. H. Rogers, Ph.D. dissertation. University of California, Davis, 1987.
"ELECTRON HEAT TRANSPORT IN A MICROWAVE DRIVEN PLASMA"

"ACKNOWLEDGEMENTS

  . . .   This dissertation has been greatly enhanced by the efforts of Z. Abou-Assaleh,  J.P. Matte, and T.W. Johnston who are responsible for the Fokker-Planck International calculations.

 . . ."

 1987
R. BECERRA-ACEVEDO and B. TERREAULT
Nuclear Instruments and Methods in Physics Research B28 (1987) 1-9
North-Holland, Amsterdam
"RANGE AND BACKSCATTERING OF HYDROGEN IONS BELOW ~ 2 keV:
FITS OF THEORY TO DATA AND APPLICATION TO PLASMA-MATERIALS INTERACTIONS"
 1986
G.G. ROSS  and B. TERREAULT
Nuclear Instruments and Methods in Physics Research 15  (1986) 146-150
"H-, H0, H+ He0, He+ AND He2+ FRACTIONS OF PROJECTILES SCATTERED FROM
14 DIFFERENT MATERIALS AT 30 TO 340 keV"

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