Transient Charge Flows Induced by the Evolution of Laser Ablation Plasma

抄録

Charge flows were induced from a laser ablation plasma to a grounded target. The current signals, which were directly measured using a current monitor, developed from negative to positive depending on the dynamically evolving plasma. The results showed that, initially the current was induced by an electron flow from the plasma plume to the surrounding wall and, after a transient phase, the current was replaced by an ion flow to the wall. The results suggest that there was a breaking of the quasi-neutral state of the ablation plasma and that an ambipolar electric field (double layer; DL) was generated during the ablation process.