超短脉冲激光与固体等离子体相互作用实验研究

Experimental Study of Interaction for Ultra-short Pulse Laser With Solid Plasmas

实验研究了超短脉冲激光(744 nm/120 fs/12 mJ)与固体(Cu)等离子体相互作用产生超热电子的能谱与角分布,利用电子磁谱仪与成像板(IP)探测器测量能谱,采用IP在入射平面内测量角分布。在无预脉冲、P极化激光45°斜入射下,采用Maxwellian分布拟合得到的超热电子温度为46 keV,超热电子主要沿靶法线方向发射。产生超热电子的主导机制为真空加热,等离子体的电荷分离势约为70 keV。

Hot electron spectrum and angular distribution generated from the interaction of ultra-short pulse laser （744 nm/120 fs/12 mJ） with solid （Cu） plasma target were studied experimentally. The electron spectrum was measured by utilizing electron-magnetic spectrometer and imaging plate （IP）, and the angular distribution was measured with IP in the incidence plan. At the condition of pre-pulse free and P polarization and 45° incidence, the temperature of hot electron fitted by Maxwellian is 46 keV, and the hot electrons are emitted mainly along the normal of targets. The dominant mechanism of hot electron generation is vacuum heating. The charge separation potential is about 70 keV.