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Title: Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate

Abstract

A physical mechanism of flares, in particular for the flare rise phase, has emerged from our 2-1/2-dimensional resistive MHD simulations. The dynamical evolution of current-sheet formation and magnetic reconnection and flux-rope acceleration subject to continuous, slow increase of magnetic shear in the arcade are studied by employing a non-uniform anomalous resistivity in the reconnecting current sheet under gravity. The simulation results directly relate the flux rope's accelerated rising motion with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. The simulation results provide good quantitative agreements with observations of the acceleration of flux rope, which manifests in the form of SXR ejecta or erupting filament or CMEs, in the low corona. Moreover, for the X-class flare events studied in this paper the peak reconnection electric field is about O(10{sup 2} V/m) or larger, enough to accelerate p articles to over 100 keV in a field-aligned distance of 10 km. Nonthermal electrons thus generated can produce hard X-rays, consistent with impulsive HXR emission observed during the flare rise phase.

Authors:
; ; ;
Publication Date:
Research Org.:
Princeton Plasma Physics Lab., NJ (US)
Sponsoring Org.:
USDOE Office of Science (SC) (US)
OSTI Identifier:
813604
Report Number(s):
PPPL-3799
TRN: US0303940
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 25 Mar 2003
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; ELECTRIC FIELDS; ELECTRONS; MAGNETIC RECONNECTION; SHEAR; SIMULATION; MAGNETOHYDRODYNAMICS (MHD); SPACE PLASMA PHYSICS; SOLAR FLARES

Citation Formats

C.Z. Cheng, Y. Ren, G.S. Choe, and Y.-J. Moon. Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate. United States: N. p., 2003. Web. doi:10.2172/813604.
C.Z. Cheng, Y. Ren, G.S. Choe, & Y.-J. Moon. Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate. United States. doi:10.2172/813604.
C.Z. Cheng, Y. Ren, G.S. Choe, and Y.-J. Moon. Tue . "Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate". United States. doi:10.2172/813604. https://www.osti.gov/servlets/purl/813604.
@article{osti_813604,
title = {Flux Rope Acceleration and Enhanced Magnetic Reconnection Rate},
author = {C.Z. Cheng and Y. Ren and G.S. Choe and Y.-J. Moon},
abstractNote = {A physical mechanism of flares, in particular for the flare rise phase, has emerged from our 2-1/2-dimensional resistive MHD simulations. The dynamical evolution of current-sheet formation and magnetic reconnection and flux-rope acceleration subject to continuous, slow increase of magnetic shear in the arcade are studied by employing a non-uniform anomalous resistivity in the reconnecting current sheet under gravity. The simulation results directly relate the flux rope's accelerated rising motion with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. The simulation results provide good quantitative agreements with observations of the acceleration of flux rope, which manifests in the form of SXR ejecta or erupting filament or CMEs, in the low corona. Moreover, for the X-class flare events studied in this paper the peak reconnection electric field is about O(10{sup 2} V/m) or larger, enough to accelerate p articles to over 100 keV in a field-aligned distance of 10 km. Nonthermal electrons thus generated can produce hard X-rays, consistent with impulsive HXR emission observed during the flare rise phase.},
doi = {10.2172/813604},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2003},
month = {3}
}

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