Ultraintense laser-cluster interactions: Effects of the cluster shape

Abstract

The disintegration of non-icosahedral rare-gas clusters in ultra-intense extreme ultraviolet (XUV) pulses is studied. The clusters quickly form a nanoplasma and evolve only according to the nanoplasma's dynamics which are determined predominately by the cluster's initial shape. It is found that the cluster's disintegration follows a simple model well predicted using only the initial structure. The main finding is that the ions disintegrate tangentially from the surface of the cluster's overall shape. In ellipsoidal clusters, the work done on the ions near the semi-minor axis by the other particles (ions and electrons) is larger than the work done on the ions near the semi-major axis. This leads to an inversion of the ellipsoidal axes due to the different axes expanding at different rates.