Particle Acceleration in Solar Flares

太阳耀斑物理学的一个关键问题是质子和其他粒子在几秒钟内加速的方式，这是脉冲y射线发射所证明的。在解释这种加速度时，最广泛接受的模型是激波加速度和阿尔芬波或磁声波的随机加速度。这两种模型都没有发展出自洽性，也没有直接的观测验证。这笔拨款将允许单环阿尔芬波随机加速模型的持续发展，作为最有可能允许理论和观测之间密切相互作用的主题。一个半环被分成3个日冕部分，分别附着在一个色球球和光球球模型上。日冕部分包括发生初始加速的源、发生进一步加速的源以外部分和质子扩散传播的输运部分。与以前的工作不同，它将是一个完整的非相对论能量模型，包括核相互作用的计算。因此，将有可能研究在整个环路中改变源中湍流的频谱和/或功率、环路尺寸等的影响。简而言之，将有可能对随机加速模型进行非常彻底的测试。快速y射线发射的观测结果来自计算的核相互作用部分。将对源中的低频湍流进行无线电诊断，以提供一种观测手段来验证其存在。这些结果将增加对这一重要研究领域的理解。总的目标是提高目前对太阳粒子加速的理解。这些粒子构成了地球环境的一部分，因此，这项工作对S/T关系很重要。//

A Key problem in solar flare physics is the manner in which protons and other particles are accelerated in a few seconds as evidenced by impulsive y-ray emission. The most widely accepted models in explaining this acceleration are shock acceleration and stochastic acceleration by Alfven or magnetosonic waves. Neither of these models has developed self-consistency or has direct observational verification. This grant will permit the consistent development of a single-loop Alfven wave stochastic acceleration model as the topic most likely to allow a close interaction between theory and observations. A half-loop is divided into 3 coronal sections attached to a model chromosphere and photosphere. The coronal sections include the source where primary acceleration occurs, a section beyond the source where further acceleration occurs and a transport section in which protons propagate diffusively. Unlike previous work, it will be a complete model for nonrelativistic energies including a nuclear interaction calculation. Thus , it will be possible to study the effect of changing the spectrum and/or power of turbulence in the source, the loop size, etc., throughout the whole loop. In short, it will be possible to put the stochastic acceleration model to a very thorough test. Observational consequences in prompt y-ray emission come from the nuclear interaction part of the calculation. A radio diagnostic of the low-frequency turbulence in the source will be developed to provide an observational means of verifying its existence. These results will increase understanding in this important area of research. The overall aim is to improve current understanding of particle acceleration at the sun. These particles form part of the earth's environment and, therefore, this work is important to S/T relations. //