Li G, Yan R, Ren C, Wang T-L, Tonge J, Mori W B
Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA.
Phys Rev Lett. 2008 Mar 28;100(12):125002. doi: 10.1103/PhysRevLett.100.125002. Epub 2008 Mar 24.
Two dimensional particle-in-cell simulations show that laser channeling in millimeter-scale underdense plasmas is a highly nonlinear and dynamic process involving longitudinal plasma buildup, laser hosing, channel bifurcation and self-correction, and electron heating to relativistic temperatures. The channeling speed is much less than the linear group velocity of the laser. The simulations find that low-intensity channeling pulses are preferred to minimize the required laser energy but with an estimated lower bound on the intensity of I approximately 5x10(18) W/cm(2) if the channel is to be established within 100 ps. The channel is also shown to significantly increase the transmission of an ignition pulse.
二维粒子模拟表明，毫米尺度低密度等离子体中的激光通道化是一个高度非线性和动态的过程，涉及纵向等离子体积累、激光软管效应、通道分叉和自校正，以及电子加热到相对论温度。通道化速度远小于激光的线性群速度。模拟发现，低强度通道化脉冲有利于将所需激光能量降至最低，但如果要在100皮秒内建立通道，估计强度下限约为I = 5×10¹⁸ W/cm²。该通道还显示出能显著提高点火脉冲的传输。
