The impact of low-Z impurities on x-ray conversion efficiency from laser-produced plasmas of low-density gold foam targets

Abstract

It is an important approach to improve the x-ray conversion efficiency of laser-ablated high-Z plasmas by using low initial density materials for various applications. However, unavoidable low-Z impurities in the manufacture process of low-density high-Z foam targets will depress this effect. A general easy-to-use analytical model based on simulations was developed to evaluate the quantitative impact of impurities within the gold foam target on laser to x-ray conversion efficiency. In addition, the x-ray conversion efficiencies of 1 g∕cm3 gold foams with two different initial contents of impurities were experimentally investigated. Good agreements have been achieved between the model results and experiments.