Probe-assisted study of the erosion plume upon the ablation of tantalum invacuum by the 308-nm excimer laser radiation

A Langmuir probe was used to study the erosion plume produced during the ab lation of a tantalum target in vacuum by radiation from an excimer laser at 308 nm, The spatial and temporal dependences of the electron and ion curre nts of the probe were obtained in real time, The electron temperature of di fferent regions of the plume at different distances from the target was mea sured for the first time from a series of dependences of the electron probe current on the probe voltage. The nonuniformity of the electron temperatur e and its lowering in different plume regions with increasing expansion tim e were determined. The ion density in the plume was determined at different distances from the target.