Generation of multiply charged silicon and germanium ions by excimer laser pulses

Abstract

Plasma bursts were produced by focusing excimer-laser (XeCl, 308 nm) pulses on Ge and Si targets. At moderate laser fluences (∼30 MW/cm²) high-intensity Ge³⁺ and Si³⁺ ion pulses were extracted from the laser-produced plasma. A peculiar electrical circuit allows a self-bunching of the beam. By time-of-flight method, the currents produced by the ions of different charge number were measured. Peak currents of 620 mA and 800 mA were recorded for Ge³⁺ and Si³⁺ ions, respectively, with an extraction voltage of only 400 V.