Ion emission from high-z laser plasmas

Abstract

The results of systematic studies of ion emission from plasmas generated in the focus of laser beams of short wavelengths, short pulse lasers (Nd:glass, 1 ns, 1060 nm; iodine, 0.5 ns, 1st harm.1315 nm 2nd harm.675 nm, 3rd harm.483 nm) are presented. The corpuscular diagnostics were based on (i) Thomson parabola spectrometer to display a general view of the ion spectra, (ii) cylindrical electrostatic ion energy analyzer to determine the detailed charge-energy ion spectra (iii) ion collectors to estimate the current density of the ion fluxes far from the focus. The ion current densities about 1 m from the focus are typically mA/cm 2 . Fairly high charge state (>50+) and simultaneously energetic (>8 MeV) ions were registered. The results are interpreted either in term of a twotemperature model of the expanding plasma or by an ion emission from a dual focal spot including a hot primary focus and a colder peripheral zone.