Sprangle P, Hafizi B, Penano JR, Hubbard RF, Ting A, Zigler A, Antonsen TM
Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375, USA.
Phys Rev Lett. 2000 Dec 11;85(24):5110-3. doi: 10.1103/PhysRevLett.85.5110.
To achieve multi-GeV electron energies in the laser wakefield accelerator (LWFA) it is necessary to propagate an intense laser pulse long distances in plasma without disruption. A 3D envelope equation for a laser pulse in a tapered plasma channel is derived, which includes wakefields and relativistic and nonparaxial effects, such as finite pulse length and group velocity dispersion. It is shown that electron energies of approximately GeV in a plasma-channel LWFA can be achieved by using short pulses where the forward Raman and modulation nonlinearities tend to cancel. Further energy gain can be achieved by tapering the plasma density to reduce electron dephasing.
要在激光尾场加速器（LWFA）中实现多GeV的电子能量，有必要使强激光脉冲在等离子体中长距离传播而不中断。推导了锥形等离子体通道中激光脉冲的三维包络方程，该方程包括尾场以及相对论和非傍轴效应，如有限脉冲长度和群速度色散。结果表明，通过使用短脉冲，在等离子体通道LWFA中可以实现约GeV的电子能量，此时正向拉曼和调制非线性趋于抵消。通过使等离子体密度呈锥形变化以减少电子退相，可以实现进一步的能量增益。
