Laser ablation of boron-carbide target

Ruby laser beam (FWHM 12 ns, average energy 3,2 J and intensity 130 GW/cm(2)) has been focused perpendicularly onto a flat B4C target. The time-resolved spectra of the B4C plasmas in the spectral region 16...32 nm at different distances from the target surface have been analyzed. The spectral lines of high-ionized carbon and boron atoms have been observed. The B4C target has been situated perpendicularly to the end of a flat smooth carbon plate and the shape of the plasma plume visualized on a carbon plate. The inner zone of the shape shows plasma cloud in a gaseous state expanding in the shape of a fan. In the outer zone solidified particulates (droplets) have been noticed. The formation of particulates is the most probably caused by interaction of the hot plasma with the cold carbon plate at the room temperature.