Ion acceleration by cw CO 2 laser irradiation in the erosion plume after ablation with excimer laser

Abstract

ABSTRACTThe erosion plume resulting from an ablation of tantalum target in vacuum with excimer laser radiation (308 nm) was studied using Langmuir probe. The spatial and temporal dependencies of electron probe currents were obtained in real time.The electron temperature of different plume regions was determined from a series of I-U characteristics taken at different distances between probe and target. It was established that the plume electron temperature is non-uniform and has a maximum value in front of the plume. The acceleration of ions on plume irradiation with CW CO2 laser recorded. Theincrease in ions energy from 25 to 50 eV was observed.Keywords: acceleration of ions, CW CO2 laser, laser ablation, tantalum, excimer XeC1 laser, electron temperature. 1. INTRODUCTION The process of ablation of solid targets has long been the subject of fundamental research. This is related both to the complexity of involved processes and to the possibility ofwide practical application 1,2 One major application of solid targetablation by laser beam is the process ofthin film deposition with pulsed laser (PLD).The processes of laser-plasma deposition require the information on characteristics of the erosion plume. The energy spectra