Аннотация:One of popular laser plasma electron acceleration mechanisms is Direct Laser Acceleration (DLA, [1]). Efficient electron energy gain by DLA is observed under resonance condition, which is determined by the phase velocity of a laser pulse in a plasma channel [2]. The method of plasma channel diagnostics by second harmonic generation from plasma channel sheath proposed is based on the same matching condition as DLA, which makes it most suitable for characterizing DLA efficiency. We demonstrated the experimental implementation of the DLA diagnostics. The PIC-simulations we have performed show that this method allows us to obtain information about phase velocity with very good accuracy ~0.05%.
