雷暴电场对LHAASO探测面宇宙线次级粒子能量的影响  

Effects of Thunderstorms Electric Field on Energy of Cosmic Rays at LHAASO

作　　者：闫瑞瑞 黄代绘[1] 赵兵 阿西克古 周勋秀[1] YAN Ruirui;HUANG Daihui;ZHAO Bing;AXI Kegu;ZHOU Xunxiu(School of Physical Science and Technology,Southwest Jiaotong University,Chengdu 610031)

机构地区：[1]西南交通大学物理科学与技术学院

出　　处：《空间科学学报》2020年第1期65-71,共7页Chinese Journal of Space Science

基　　金：国家重点研发计划项目(2018YFA0404201);国家自然科学基金项目(11475141,11847307)共同资助

摘　　要：采用Monte Carlo方法,通过模拟研究了不同强度雷暴电场对LHAASO探测面宇宙线次级电子能量的影响.在电场作用下,电子的能量分布发生了变化.在低能段总电子数目增加明显,而在高能段电场的影响不明显.当电场强度为1700 V·cm-1(大于逃逸电场)时,能量<120MeV的电子被加速,能量<60MeV的总电子数目呈指数增长(增幅高达约2252%),雷暴电场对次级粒子的加速机制与相对论电子逃逸雪崩机制(RREA)相符.当电场强度为1000 V·cm-1(小于逃逸电场)时,能量<70 MeV的电子被加速,其数目明显增加,但是增幅(约86%)远小于逃逸电场时的幅度.对电场强度小于逃逸电场时的雷暴电场加速宇宙线次级粒子的物理机制进行了讨论.研究结果可为理解LHAASO实验数据特点以及研究雷暴期间宇宙线强度的变化等提供参考.The Large High Altitude Air Shower Observatory(LHAASO) is located in Daocheng,Sichuan.Featured with frequent thunderstorms in summer,it is beneficial to study the influence of atmospheric electric field on cosmic rays during thunderstorms.In this paper,Monte Carlo simulations are performed to study the effects of thunderstorms electric field on positrons and electrons at LHAASO.The energy distribution of electrons changes in the field.In low energy region,the total number of electrons and positrons increases significantly,while at high energies,it does not change obviously.In an electric field of 1700 V·cm-1,above the threshold field of the Relativistic Runaway Electron Avalanche(RREA) process,the electrons with energy less than 120 MeV can be accelerated.While the energy is below 60 MeV,the number of electrons increases exponentially,with the increase amplitude up to about 2252%.It is consistent with the theory of RREA.In an field of1000 V·cm-1(below the threshold of the RREA process),electrons with energy less than 70 MeV can be accelerated,and its quantity significantly increases,but the amplification(about 86%) is far lower than that of the critical field of the RREA process.The results may provide important information to study the variations of cosmic ray intensity at LHAASO detection surface during thunderstorms.

关 键 词：雷暴电场 能量 Monte Carlo模拟 LHAASO实验 

分 类 号：P353[天文地球—空间物理学]