物理学报Issue(16)：1-7,7.DOI:10.7498/aps.64.165201
激光驱动磁重联过程中的喷流演化和电子能谱测量∗
Measurement of jet evolution and electron energy sp ectrum during the pro cess of laser-driven magnetic reconnection
摘要
Abstract
Magnetic reconnection (MR) is a universal physical process in plasma, in which the stored magnetic energy is converted into high-velocity flows and energetic particles. It is believed that MR plays an important role in many plasma phenomena such as solar fare, gamma-ray burst, fusion plasma instabilities, etc.. The process of MR has been studied in detail by dedicated magnetic-driven experiments. Here, we report the measurements of magnetic reconnection driven by Shenguang II lasers and Gekko XVII lasers. A collimated plasma jet is observed along the direction perpendicular to the reconnection plane with the optical probing. The present jet is very different from traditional magnetic reconnection outflows as known in the two-dimensional reconnection plane. In our experiment, by changing the delay of optical probing beam, we measure the temporal evolution of jet from 0.5 ns to 2.5 ns and its velocity around 400 km/s is deduced. High-collimated jet is also confirmed by its strong X-ray radiation recorded by an X-ray pinhole camera. With the help of optical interferograms we calculate the jet configuration and its density distribution by using Abel inverting technique. A magnetic spectrometer with an energy range from hundred eV up to one MeV is installed in front of the jet, in the direction perpendicular to the reconnection plane, to measure the accelerated electrons. Two cases are considered for checking the acceleration of electrons. The results show that more accelerated electrons can be found in the reconnection case than in the case without reconnection. We propose that the formation and collimation of the plasma jet, and the electron energy spectrum may be possible directly influenced by the reconnection electric field, which is very important for understanding the energy conversion in the process of MR and establishment of the theoretical model. Finally the electron energy spectra of three different materials Al, Ta and Au are also shown in our work. The results indicate that the higher atomic number material can obtain a better signal-noise ratio, which provides some helpful references for our future work.关键词
磁重联/电子加速Key words
magnetic reconnection/electron acceleration引用本文复制引用
张凯,王琛,贺昊,尹传磊,廖国前,方远,杨骕,远晓辉,梁贵云,王菲鹿,朱健强,仲佳勇,丁永坤,张杰,赵刚,裴晓星,李玉同,阪和洋一,魏会冈,袁大伟,李芳,韩波..激光驱动磁重联过程中的喷流演化和电子能谱测量∗[J].物理学报,2015,(16):1-7,7.基金项目
国家重点基础研究发展计划(批准号:2013CBA01503)、国家自然科学基金(批准号:11205015,11273033,11135012)和北京科技新星(批准号：Z131109000413050)资助的课题.@@@@* Project supported by the National Basic Research Program of China (Grant No.2013CBA01503), the National Natural Science Foundation of China (Grant Nos.11205015,11273033,11135012), and the Beijing Nova Program, China (Grant No. Z131109000413050) （批准号:2013CBA01503）
