Hybrid simulations of fast electron propagation including magnetized transport and non-local effects in the background plasma

作者：Williams B E R^*; Kingham R J

来源：Plasma Physics and Controlled Fusion, 2013, 55(12): 124009.

DOI：10.1088/0741-3335/55/12/124009

We present the first results from a 2D VFP-PIC hybrid code for fast electron transport which solves the Vlasov-Fokker-Planck (VFP) equation for the background electrons using the code IMPACT. This new type of hybrid code captures full Braginskii electron transport including magnetization, non-local corrections and electron inertial effects. We consider propagation of a relativistic electron beam, generated by a laser of intensity I = (1-5) x 10(19) W cm(-2) and focal radius of a few microns, inside a near solid-density carbon target. Electron thermal transport out of the resistively heated background plasma is strong enough to compete with ohmic heating after about a picosecond. The effect of heat flow on the plasma temperature is sufficient to alter resistive magnetic field generation over time scales beyond a few picoseconds. This includes removal of beam-hollowing field near the beam injection point and re-emergence of a collimating magnetic field. Background electrons become weakly magnetized after a few picoseconds; enough for magnetized transport effects to significantly alter the evolution of the background plasma temperature and the long term evolution of the fast electron filaments. A practical estimate for the evolution of electron magnetization is presented and shown to agree with the simulation results. Non-local modifications to transport of up to 20% have been found in this situation.

• 出版日期2013-12