Ion acceleration by hot electrons in microclusters

A self-consistent analytical description is presented for collisionless expansion of a fully ionized cluster with a two-component electron distribution. The problem is solved for an initial “water-bag” distribution of hot electrons with no angular momentum, which reflects the mechanism of electron heating. This distribution evolves in time due to adiabatic cooling of hot electrons. The solution involves a cold core of the cluster, a thin double layer at the cluster edge, and a quasineutral flow with a rarefaction wave. The presented analysis predicts a substantial number of accelerated ions with energies greater than the cutoff energy of the initial distribution of the hot electrons. © 2007 American Institute of Physics. #DOI: 10.1063/1.2747633$