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 f...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.展开更多
In the past two years,many progresses are made in magnetospheric physics by using either the data of Double Star Program,Cluster and THEMIS missions,or by computer simulations. This paper briefly reviews these works b...In the past two years,many progresses are made in magnetospheric physics by using either the data of Double Star Program,Cluster and THEMIS missions,or by computer simulations. This paper briefly reviews these works based on papers selected from the 80 publications from April 2010 to April 2011.The subjects covered various sub-branches of magnetospheric physics,including geomagnetic storm,magnetospheric substorm,etc.展开更多
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
文摘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.
文摘In the past two years,many progresses are made in magnetospheric physics by using either the data of Double Star Program,Cluster and THEMIS missions,or by computer simulations. This paper briefly reviews these works based on papers selected from the 80 publications from April 2010 to April 2011.The subjects covered various sub-branches of magnetospheric physics,including geomagnetic storm,magnetospheric substorm,etc.
