采用超薄双层靶提高质子束的单能性  

Generation of quasi-monoenergetic proton beam by using ultrathin double-layer target

作　　者：陈红雅[1,2] 徐涵[3,4] 银燕[1] 田成林[1] 邵福球[1] 马燕云[1,4] 

机构地区：[1]国防科学技术大学理学院物理系,长沙410073 [2]空军工程大学理学院数理系,西安710051 [3]国防科学技术大学计算机学院,长沙410073 [4]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《强激光与粒子束》2010年第7期1548-1552,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(10605038,10975185,10976031);国防科学技术大学优秀研究生创新资助项目(S080202)

摘　　要：利用1维粒子模拟程序,研究了超短超强激光脉冲与超薄双层靶(基底层和加速层厚度均为nm量级)相互作用产生准单能质子束的过程。研究表明,基底层厚度及加速层厚度对质子能谱的影响至关重要。减小基底层厚度,靶后静电场增强,质子的最大能量显著增大;减小加速层厚度,靶后静电场分布变得更加均匀,质子能谱中心能量变化不大,单能性变好。通过优化参数,获得了能散度为7%的准单能质子束。The quasi-monoenergetic proton beam generated from ultra-short ultra intense laser pulse interacting with ultra- thin double-layer target （both the thickness of the substrate layer and that of the acceleration layer are in nanometer scale） is ex- amined by one-dimensional particle-in-cell simulation. The thickness of the substrate and the acceleration layer is crucial to the proton spectrum. The quasi-static electric field becomes stronger as the substrate layer thickness decreases, which results in the enhancement of the maximum proton energy. Reducing the acceleration layer thickness induces a more uniform quasi-static electric field. As a result, the proton spectrum becomes more monoenergetic with nearly unchanged mean energy. The quasi-monoener- getic proton with an energy spread of about 7 %has been produced by optimizing parameters.

关 键 词：粒子模拟方法 超薄双层靶 质子能谱 准单能 

分 类 号：O53[理学—等离子体物理]