激光波长对超热电子产生影响的实验研究  

Experimental Investigation of Effect on Hot Electron Produced by Various Wavelength Laser

作　　者：李业军[1] 王雷剑[1] 路建新[1] 张骥[1] 张海峰[1] 汤秀章[1] 

机构地区：[1]中国原子能科学研究院核技术应用研究所,北京102413

出　　处：《原子能科学技术》2008年第B09期349-353,共5页Atomic Energy Science and Technology

基　　金："863"高技术资助项目;国家自然科学基金资助项目(10334110)

摘　　要：实验研究了两种波长超短脉冲激光(744 nm/120 fs/12 mJ、248 nm/420 fs/35 mJ)与固体(Cu)等离子体的相互作用,利用电子磁谱仪与成像板探测器测量了激光入射平面内超热电子的能谱与角分布。在无预脉冲、P极化激光45°斜入射的条件下,采用Maxwellian分布拟合得到的超热电子温度分别为46和19.4 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,实验验证了真空吸收定标率Th≈4.11×10-2(Iλ2)1/2.54(keV)。等离子体的电荷分离势分别为70和45 keV。The interactions of two kinds of wavelength ultra-short pulse （744 nm/ 120 fs/12 mJ, 248 nm/420 fs/35 mJ） laser with solid （Cu） plasma targets were experimentally investigated, and the hot electron spectra and angular distribution were measured by electron magnetic spectrometer and imaging plate （IP） detectors in laser incident plane. At the conditions of pre-pulse free and P polarization and 45° incidence, the temperatures of hot electron fitted by Maxwellian are 46 and 19.4 keV, respectively, and the hot electrons are emitted mainly along the normal direction of targets. The dominant mechanisms of hot electron generating are vacuum heating （VH）. It is experimentally validated that the scaling law of VH is Th≈4.11 ×10^-2 （Iλ^2）^1/2.54 （keV）. The charge separation potential of plasma are about 70 and 45 keV, respectively.

关 键 词：超短脉冲激光 波长 超热电子 角分布 

分 类 号：TN249[电子电信—物理电子学]