Magnetic field annihilation and reconnection driven by femtosecond lasers in inhomogeneous plasma  

作　　者：YouYuan Wang FeiYu Li Min Chen SuMing Weng QuanMing Lu QuanLi Dong ZhengMing Sheng Jie Zhang 

机构地区：[1]Key Laboratory for Laser Plasmas (Ministry of Education) and School of Physics and Astronomy, Shanghai Jiao Tong University [2]Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University [3]Scottish Universities Physics Alliance (SUPA), Department of Physics,University of Strathclyde [4]Key Lab of Geospace Environment, Chinese Academy of Sciences, Department of Geophysics and Planetary Science, University of Science and Technology of China [5]School of Physics and Optoelectronic Engineering, Ludong University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2017年第11期68-75,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant No.2013CBA01500);the National Natural Science Foundation of China(Grant Nos.11421064,and 11220101002);a Leverhulme Trust Research Project Grant at University of Strathclyde

摘　　要：The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽(n/) × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection(annihilation) in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽（n/） × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection（annihilation） in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.

关 键 词：magnetic reconnection laser wakefield magnetic field generation 

分 类 号：O53[理学—等离子体物理]