靶材偏置低电压对激光等离子体诱导靶上电势信号的影响

Study on the electrical potential signals induced by laser plasma in the target with bias-voltage

针对激光等离子体在Cu靶上诱导产生的电势信号展开实验研究,主要讨论了靶材偏置低电压时对电势信号的影响.实验结果表明,外加低电压时,靶上电势信号呈现单峰脉冲结构,且靶材偏置负压时为正脉冲,偏置正压时为负脉冲,脉冲幅值随偏置电压增大而增大.通过对靶上电势信号演化特性的详细分析,从等离子体荷电效应出发,结合靶材偏压造成的电场效应成功解释了靶材偏压对靶上电势信号的影响.

The electrical potential signals induced by laser-plasma generated on a copper target with bias-voltage using a Nd： YAG laser （7 ns） were detected, and the effect of the additional voltage on the potential signals was mainly studied. The experimental results show a single-peak distribution in the temporal profile, which is positive/＇or negative bias voltage and negative peak when with positive bias voltage. Taking into account the effect of plasma charging and the electric field produced by the target biasvoltage, a clear explanation of the observed effect is given.