Proton extraction by laser ablation of transition metals

A study on the proton beams extraction from a plasma generated by pulsed laser ablation by targets containing transition metals is presented. The targets used were pure disks of titanium and tantalum and disks of TiH2, obtained by compression of TiH2 powder. The plasma was produced by means of a nanosecond excimer KrF laser operating at low irradiance (10(9)-10(10) W/cm(2)). The proton and ions emission was analyzed by the time-of-flight technique using a Faraday cup as ion collector. Studies on the produced protons and ions at different laser irradiances from 2 to 15 GW/cm(2) were performed. The characterization showed that it is possible to obtain good proton fluxes from these targets, up to 10(11) proton/pulse. The results obtained are very interesting if compared with those available in literature where proton fluxes per pulse ranging from 10(8) to 10(9) by hydride targets were obtained, at the same laser irradiances. (C) 2014 Elsevier B.V. All rights reserved.