Fast neutron production from lithium converters and laser driven protons
Fast neutron production from lithium converters and laser driven protons
复制标题
锂转换器和激光驱动质子快速产生中子
DOI：
10.1063/1.4803648
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发表时间：
2013
影响因子：
2.2
通讯作者：
K. Akli
中科院分区：
文献类型：
--
作者：
M. Storm;Sheng Jiang;D. Wertepny;C. Orban;J. Morrison;C. Willis;E. Mccary;P. Belancourt;J. Snyder;E. Chowdhury;W. Bang;E. Gaul;G. Dyer;T. Ditmire;R. Freeman;K. Akli
在德克萨斯大学奥斯汀分校的德克萨斯·佩特瓦特激光设备上，已经进行了从7Li(p，n)7Be反应中产生60J，180fs激光脉冲的中子的实验。利用靶法向鞘加速机制，从薄靶膜的背面加速质子。这些中子是在核反应中产生的，核反应是由质子轰击天然同位素丰度的纯锂箔引起的。中子能量范围高达2.9 MeV。总的产额估计为1.6 × 10~7个中子/立体。一台用于对目标背面成像的极端紫外光相机，将质子产额和峰值能量的变化与目标背面烧蚀相关联。使用流体动力学程序Flash进行的计算表明，烧蚀是由强度较长的激光预脉冲造成的。烧蚀严重限制了质子加速和中子产额。
Experiments to generate neutrons from the 7Li(p,n)7Be reaction with 60 J, 180 fs laser pulses have been performed at the Texas Petawatt Laser Facility at the University of Texas at Austin. The protons were accelerated from the rear surface of a thin target membrane using the target-normal-sheath-acceleration mechanism. The neutrons were generated in nuclear reactions caused by the subsequent proton bombardment of a pure lithium foil of natural isotopic abundance. The neutron energy ranged up to 2.9 MeV. The total yield was estimated to be 1.6 × 107 neutrons per steradian. An extreme ultra-violet light camera, used to image the target rear surface, correlated variations in the proton yield and peak energy to target rear surface ablation. Calculations using the hydrodynamics code FLASH indicated that the ablation resulted from a laser pre-pulse of prolonged intensity. The ablation severely limited the proton acceleration and neutron yield.