Particle Acceleration in Magnetic Reconnection Regions in the Solar Corona

日冕磁重联区域的粒子加速

• 批准号: 9813933
• 负责人: Martin Lee
• 金额: $ 21.1万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-15 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9813933&HistoricalAwards=false
• 关键词: Particle; Acceleration; Magnetic; Reconnection; Regions

The investigators will study electron and proton acceleration by the electric field associated with magnetic reconnection in the solar corona. Acceleration of charged particles to energies far exceeding the thermal energy is ubiquitous in cosmic plasma, especially in solar flares. The goal is to model self-consistently the rapid conversion of the coronal magnetic energy to the kinetic energy of fast particles by virtue of the reconnection process. Parameters of reconnecting current sheets will be determined self-consistently using a system of balance equations following from conservation laws. Regimes of both turbulent and entirely collisionless reconnection will be considered. Properties of the flaring coronal plasma and flare loops will be calculated and used as a means of testing the reconnection model. The n the energies, acceleration times, electron/proton ratios, and fluxes of accelerated particles will be calculated for various conditions in the corona. Electron-rich impulsive flares and X-ray hardening gradual flares that produce geo-effective protons will be specifically considered. New processes such as acceleration in time-dependent electric fields at magnetic null points and second-step acceleration in collapsing magnetic traps will be investigated. The study will emphasize analytical methods as well as comparisons between theoretical predictions and observations by Compton GRO, Yohkoh, and SOHO. Overall, the work is intended to be a step towards a unified modeling of global magnetic energy release and particle acceleration in flares and flare-like phenomena in space.

研究人员将研究太阳日冕中与磁场重联相关的电场对电子和质子的加速作用。带电粒子加速到远远超过热能的能量在宇宙等离子体中普遍存在，特别是在太阳耀斑中。我们的目标是通过重联过程，自洽地模拟日冕磁能到快粒子动能的快速转换。重新连接电流片的参数将使用遵循守恒定律的平衡方程系统自洽地确定。将考虑动荡和完全无碰撞的重新连接制度。将计算耀斑日冕等离子体和耀斑环路的性质，并将其用作测试重联模型的手段。在日冕中的各种条件下，将计算加速粒子的能量、加速时间、电子/质子比和通量。富含电子的脉冲耀斑和产生地效质子的X射线硬化渐变耀斑将被特别考虑。将研究新的过程，如磁场零点处随时间变化的电场的加速和坍塌磁禁闭中的第二步加速。这项研究将强调分析方法，以及康普顿·格罗、Yohkoh和SOHO的理论预测与观测之间的比较。总体而言，这项工作的目的是朝着建立全球磁能释放和空间耀斑和类似耀斑现象的粒子加速的统一模型迈出一步。