Material ablation and plasma plume expansion study from Fe and graphite targets in Ar gas atmosphere

Abstract

Study of expansion dynamics of pulsed-laser ablation plasmas from Fe and graphite targets is presented. A 532 nm Q-switched Nd:YAG laser with fluence of 30 J cm−2 is used to ablate the Fe and graphite targets in various Ar ambient gas pressures. Plasma ablation parameters for the two target materials are estimated using snow-plow and shock-wave models, which show that the laser beam energy deposited to ablated species remains at 70% for both targets at all ambient pressures. The plume splitting was observed, more prominently, for Fe plasma as it moves faster compared to graphite plasma. The difference in plasma plume fronts’ speeds for different targets was attributed to the significant difference in mass of the ablated plasma for two targets, as estimated from simulation results.