Acceleration of neutrals in a nanosecond laser produced nickel plasma

Abstract

Time of flight dynamics of slow neutrals, fast neutrals, and ions from a nanosecond laser produced nickel (Ni) plasma are investigated. Species arrival times confirm the hypothesis that fast neutrals are formed by the recombination of fast ions with free electrons. Both neutrals and ions are found to accelerate for a short interval immediately after ablation, which is attributed to internal Coulomb forces which create electrostatic potentials resulting in the charged particle acceleration. This process is further enhanced by laser-plasma energy coupling. Emission from neutrals could be measured for longer axial distances in the plume compared to that of ions confirming that the ions recombine to form neutrals as they move away from the target surface.