Concerted Manipulation of Laser Plasma Dynamics with two laser pulses

摘要

In this article we present experimental results from a counter-propagating two laser pulse experiment at high intensity and using ultrathin gold and plastic foil targets. We applied one laser pulse as a pre-pulse with an intensity of up to lx10~(18) W/cm~2. By this method we manipulated the pre-plasma of the foil target with which the stronger laser pulse with an intensity of 6x10~(l9)W/cm~2 interacts. This alters significantly subsequent processes from the laser plasma interaction which we show the ion acceleration and high harmonic generation. On the one hand, the maximum kinetic ion energy and the maximum charge state for gold ions decline due to the pre-heating of the target in the time range of few ps, on the other hand the number of accelerated ions is increased. For the same parameter range we detected a significant raise of the high harmonic emission. Moreover, we present first experimental observations, that when the second laser pulse is applied as a counter-propagating post-pulse the energy distribution of accelerated carbon ions is charge selective altered. Our findings indicate that using this method a parametric optimization can be achieved, which promises new insights about the concurrent processes of the laser plasma dynamics.