Europhys. Lett.
Volume 72, Number 6, December 2005
Page(s) 955 - 961
Section Physics of gases, plasmas and electric discharges
Published online 16 November 2005
Europhys. Lett., 72 (6), pp. 955-961 (2005)
DOI: 10.1209/epl/i2005-10329-2

Fluid theory of magnetic-field generation in intense laser-plasma interaction

Bin Qiao1, X. T. He2, 3 and Shao-ping Zhu2

1  Graduate School of China Academy of Engineering Physics P. O. Box 2101, Beijing 100088, PRC
2  Institute of Applied Physics and Computational Mathematics P. O. Box 8009, Beijing 100088, PRC
3  Department of Physics, Zhejiang University - Hangzhou 310027, PRC

received 11 July 2005; accepted in final form 14 October 2005
published online 16 November 2005

Using the ten-moment Grad system of hydrodynamic equations, a self-consistent fluid model is presented for the generation of spontaneous magnetic fields in intense laser-plasma interaction. The generalized vorticity is not conserved as opposed to previous studies, for the nondiagonal stress force is considered. Equations for both the axial magnetic field Bz and the azimuthal one $B_{\theta}$ are simultaneously derived from a fluid scheme for the first time in the quasi-static approximation, where the low-frequency phase speed vp is much smaller than the electron thermal speed vte. It is found that the condition $v_{p}\gg v_{te}$, widely used as cold-fluid approximation, where Bz is incomplete, is improper. The profiles of Bz and $B_{\theta}$ as well as the plasma density cavitation are analyzed. Their dependences on the laser intensity are also discussed.

52.38.Fz - Laser-induced magnetic fields in plasmas.
52.35.Mw - Nonlinear phenomena: waves, wave propagation, and other interactions (including parametric effects, mode coupling, ponderomotive effects etc.).
52.57.Kk - Fast ignition of compressed fusion fuels.

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