Scaling Law for fast electron beam intensity in fast ignition

Abstract

FI3 Integrated simulations with the heating laser whose pulse duration is 10[ps] have been performed to investigate the core heating property of FIREX-I experiments. As the preformed plasma was pushed by the Ponderomotive force, the electron density increased in time and the fast electron beam intensity decreased. It was found that the fast electron beam intensity well scaled as the inverse square root of the electron density at the laser front. If the preformed plasma had the short scale length profile, the average core temperature quickly rose but shortly saturated because the fast electron beam intensity decreased. With the longer scale length preformed plasma, the beam intensity of fast electrons was maintained and the core heating was sustained for a longer time, the core reached higher average temperature.