Inverse bremsstrahlung absorption and the evolution of electron distributions accounting for electron-electron collisions

Journal Article · Wed Nov 15 00:00:00 EST 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2370725· OSTI ID:20860399

Suming, Weng; Zhengming, Sheng; Minqing, He; Huichun, Wu; Quanli, Dong; Jie, Zhang ^[1]

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1. Laboratory of Optical Physics, Institute of Physics, CAS, Beijing 100080 (China)

Two-dimensional Fokker-Planck simulations have been conducted to investigate the inverse bremsstrahlung absorption and the evolution of the electron distribution function (EDF), where the electron-electron (e-e) collisions are taken into account, allowing for highly anisotropic electron distributions. The numerical results show that the anisotropic part of the EDF is comparable to the isotropic part even for a moderate laser field. The resulting EDF is no longer a simple super-Gaussian, but a hybrid of the super-Gaussian and Maxwellian distributions. Furthermore, the e-e collisions tend to enhance the inverse bremsstrahlung absorption; the contribution ratio of e-e collisions to the inverse bremsstrahlung absorption rate increases with increasing ion charge state Z{sub i} in the high laser frequency regime, while it decreases in the low laser frequency regime. It indicates that one cannot simply neglect the e-e collisions in high Z{sub i} cases.

• OSTI ID: 20860399
• Journal Information: Physics of Plasmas, Vol. 13, Issue 11; Other Information: DOI: 10.1063/1.2370725; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABSORPTION
ANISOTROPY
BREMSSTRAHLUNG
CHARGE STATES
DISTRIBUTION
DISTRIBUTION FUNCTIONS
ELECTRON-ELECTRON COLLISIONS
ELECTRONS
EVOLUTION
FOKKER-PLANCK EQUATION
IONS
LASER RADIATION
LASERS
LIGHT TRANSMISSION
PLASMA
PLASMA SIMULATION
RADIATION TRANSPORT
TWO-DIMENSIONAL CALCULATIONS