超热电子的产生与输运背向辐射的实验研究

A experimental studie of hot electrons generation and transport in targets at the rear-side radiation

报道了在100TW fs激光器上采用电子磁谱仪和光学CCD积分成像相机分别对激光-固体靶相互作用在靶背方向产生的超热电子能谱及其光学渡越辐射进行的测量.能谱测量结果显示:超热电子能谱呈单温类-麦克斯韦分布,拟合的温度为107 keV;光学渡越辐射(OTR)测量结果显示:OTR是由于超热电子输运穿越固体靶所致,而辐射区域呈圆盘状、有发散角、有光强分布;如果考虑超热电子的产生和加热机制,则占主导地位的加热机制是共振吸收对电子的加热.

This paper reports hot electron energy spectrum measured with electron spectrometer,and Optical Transition Radiation measured with optical time-integrated image of CCD during the interaction of laser-solid target in targets at the rear-side radiation of laser on 20 Terawatt femtosecond laser facility. It shows that hot electron energy spectrum fitted with one-temperature like- Maxwellian distribution,with temperature of hot electrons T ≈107 keV. Due Optical Transition Radiation（OTR） is produced by the hot electrons transport through solid targets,region of OTR is have lager radiation angle and optical intensity distribution. If considering the generated and acceleration mechanism of hot electrons, the main acceleration of hot electron comes from resonance absorption.