空泡机制产生betatron X射线辐射的数值模拟  

Numerical simulation of betatron X-ray emission from laser-produced wakefield accelerated electrons

作　　者：杨祖华[1,2] 赵宗清[2] 谭放[2] 曹磊峰[2] 谷渝秋[2] 肖沙里[1] 闫永宏[2] 余金清[2] 范伟[2] 钱凤[1,2] 

机构地区：[1]重庆大学光电工程学院,重庆400030 [2]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》2012年第8期1851-1855,共5页High Power Laser and Particle Beams

摘　　要：针对SILEX钛宝石激光器参数,采用PIC数值模拟程序VORPAL对激光尾波场加速进行了模拟,得到了电子轨迹及能量数据,进而通过理论计算得到了空泡机制下X射线辐射特性。结果表明,空泡机制下高能电子在空泡中做betatron振荡且多数电子被加速到170 MeV左右;加速能量较低的电子(约100 MeV),其辐射谱为临界能量约3 keV的类同步辐射谱,发散角约为8 mrad,而能量较高的电子(约170 MeV)对应的光子临界能量约为10 keV。To find a solution for the high brightness,ultra-short pulse X-ray source,the betatron X-ray mechanism was studied.It is based on the interactions which generate the laser wake field acceleration（LWFA）,between the ultra-intense short laser and the plasma.These accelerated electrons make betatron oscillations in the transverse fields of the bubble and emit high brightness and ultra-short X-ray pulses（about fs）.Also,this kind of source has the advantages of small size,low cost.The numerical calculations of the emission of the betatron X-rays were carried out with 2D-PIC simulations and the data processing software.Synchrotron spectra with critical energy of 3 keV and 10 keV which are radiated by the lower energy electrons（about 100 MeV） and the higher energy electrons（about 170 MeV） respectively,are reported and the emission is confined to a small angle of about 8 mrad,which has a good agreement with the theoretical results.

关 键 词：激光尾场加速 betatron X射线 空泡 类同步辐射谱 粒子模拟 

分 类 号：O539[理学—等离子体物理]