摘要
A new combined Fermi, betatron, and turbulent electron acceleration mechanism is proposed in interaction of magnetic islands during turbulent magnetic reconnection evolution in explosive astrophysical phenomena at large temporal-spatial scale(LTSTMR), the ratio of observed current sheets thickness to electron characteristic length, electron Larmor radius for low-β and electron inertial length for high-β, is on the order of 10^(10)–10^(11); the ratio of observed evolution time to electron gyroperiod is on the order of 10~7–10~9).The original combined acceleration model is known to be one of greatest importance in the interaction of magnetic islands; it assumes that the continuous kinetic-dynamic temporal-spatial scale evolution occurs as two separate independent processes.In this paper, we reconsider the combined acceleration mechanism by introducing a kinetic-dynamic-hydro full-coupled model instead of the original micro-kinetic or macro-dynamic model.We investigate different acceleration mechanisms in the vicinity of neutral points in magnetic islands evolution, from the stage of shrink and breakup into smaller islands(kinetic scale), to the stage of coalescence and growth into larger islands(dynamic scale), to the stages of constant and quasi-constant(contracting-expanding) islands(hydro scale).As a result, we give for the first time the acceleration efficiencies of different types of acceleration mechanisms in magnetic islands' interactions in solar atmosphere LTSTMR activities(pico-, 10^(–2)–10~5 m; nano-, 10~5–10~6 m; micro-, 10~6–10~7 m; macro-, 10~7–10~8 m; large-,10~8–10~9 m).
A new combined Fermi, betatron, and turbulent electron acceleration mechanism is proposed in interaction of magnetic islands during turbulent magnetic reconnection evolution in explosive astrophysical phenomena at large temporal-spatial scale(LTSTMR), the ratio of observed current sheets thickness to electron characteristic length, electron Larmor radius for low-β and electron inertial length for high-β, is on the order of 10^(10)–10^(11); the ratio of observed evolution time to electron gyroperiod is on the order of 10~7–10~9).The original combined acceleration model is known to be one of greatest importance in the interaction of magnetic islands; it assumes that the continuous kinetic-dynamic temporal-spatial scale evolution occurs as two separate independent processes.In this paper, we reconsider the combined acceleration mechanism by introducing a kinetic-dynamic-hydro full-coupled model instead of the original micro-kinetic or macro-dynamic model.We investigate different acceleration mechanisms in the vicinity of neutral points in magnetic islands evolution, from the stage of shrink and breakup into smaller islands(kinetic scale), to the stage of coalescence and growth into larger islands(dynamic scale), to the stages of constant and quasi-constant(contracting-expanding) islands(hydro scale).As a result, we give for the first time the acceleration efficiencies of different types of acceleration mechanisms in magnetic islands' interactions in solar atmosphere LTSTMR activities(pico-, 10^(–2)–10~5 m; nano-, 10~5–10~6 m; micro-, 10~6–10~7 m; macro-, 10~7–10~8 m; large-,10~8–10~9 m).
基金
supported by the strategic priority research program of CAS (XDA17040507, XDA15010900)
the national basic research program of China (2013CBA01503)
the key program of NSFC (11333007)
joint funds of NSFC(U1631130)
frontier science key programs of CAS (QYZDJ-SSWSLH012)
the program for innovation team of Yunnan Province
the program for Guangdong introducing Innovative and entrepreneurial teams (2016ZT06D211)
the special program for applied research on super computation of the NSFC-Guangdong joint fund (second phase) under No.U1501501