短脉冲强激光打靶产生的质子角分布实验研究  

Experimental study about angular distribution of protons emitted from thin solid target irradiated by supershort laser

作　　者：朱托[1,2] 杨家敏[1,2] 王哲斌[1,2] 赵阳[1,3] 张继彦[1,2] 胡智民[1,2] 丁耀南[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [2]中国工程物理研究院高温高密度等离子体物理国家重点实验室,四川绵阳621900 [3]华中科技大学光电子科学与工程学院武汉光电国家实验室,武汉430074

出　　处：《强激光与粒子束》2008年第10期1645-1648,共4页High Power Laser and Particle Beams

摘　　要：采用短脉冲强激光辐照固体双层薄靶的方式对质子束的产生及质子束角分布开展了实验研究。在SILEX-Ⅰ短脉冲激光装置上利用脉宽为30 fs的强激光辐照背面镀有CH膜的金膜靶,在距离靶背3.3 cm处采用CR39记录靶背出射的质子角分布。通过分析靶背出射质子的角分布,研究了激光功率密度和对比度对质子加速机制的影响。研究结果表明:占主导地位的质子产生和加速机制对激光预脉冲比较敏感。激光预脉冲较弱时,靶背壳电场加速机制占主导地位;当激光预脉冲较强时,靶前加速机制占主导地位。此外,还对导致质子环形分布的磁场大小进行了估算。Proton generation and angular distribution produced by supershort laser pulse irradiating thin solid Au target were investigated. The experiment was performed on the SILEX-I laser facility. CR39 was mounted 3.3 cm behind the target to record the protons from the target. How the laser intensity and laser contrast ratio influenced the mechanism of proton acceleration was studied by analysing the proton angular distributions. The primary acceleration mechanism of proton is sensitive to the prepulse. When the prepulse is weak, the primary proton acceleration is target normal sheath acceleration. When the prepulse is strong, most protons is primarily accelerated in the front of target.

关 键 词：质子 质子加速 角分布 超短脉冲激光 预脉冲 

分 类 号：O532.25[理学—等离子体物理]