Mass distributions of ions extracted from target cavity confined plasmas produced by nanosecond laser pulses

Abstract

Ion and electron current signals produced from a solid graphite target under 1064 nm nanosecond laser pulse irradiation were investigated. A cavity is formed by laser incidence at the center of the target surface at 10 Hz repetition rate while being rotated along its axis. Ion mass distributions were recorded via a time-of-flight spectrum coupled with a detector assembly attached along the propagation axis. Peak shifts towards slower times were observed for increasing number of pulses. The effect of magnetic detection on the ion current signals is investigated, and showed significant peak shifts for 20 GW/cm 2 laser power density.