The effect of laser-produced plasma expansion on the ion population

Abstract

Listen

Translate article

Changes in the ion population during the expansion of Ag, Cu, Pb, and Ta laser-produced plasmas in vacuum were simultaneously measured with two coaxial ion collectors between 82 and 187 cm from a target. The plasma was produced with an iodine laser delivering a power density up to ∼1015 W/cm2 onto the target. It was experimentally proved that the charge Q of expanding ions and the corresponding ion current density j are really decreasing with the distance L as Q∝L−2 and j∝L−3, respectively. It implies that the “freezing” of charge states dominates in that interval of L.