标题： 太阳加速粒子事件中元素的丰度 显示英文标题

标题： Element Abundances in Impulsive Solar Energetic Particle Events

摘要： 我们概述并讨论了一个模型，用于解释脉冲太阳高能粒子（SEP）事件中超铁元素丰度增强的现象，其中经常可以看到大质量依赖的丰度增强。 这是对第一电离势（FIP）效应的拟磁力模型的一种变化，即相对于中性元素，像Fe、Mg和Si这样的在太阳色球层中电离的元素在日冕中的丰度增加。 这样，分馏区域被放置在色球层，并与太阳包层相连，使得巨大的丰度变化可能发生，这在日冕分馏区域的情况下可能会有问题。 质量无关的FIP分馏转变为质量相关的脉冲SEP分馏的主要机制是色球层中声波的抑制。 导致分馏的拟磁力必须来自扭旋阿尔芬波，这些波比剪切波与慢模式的耦合效果差得多，而来自光球对流的向上传播声波必须在阿尔芬速度和声速相等的色球层有效地转换为快模式，并随后完全内反射。 我们进一步讨论了被认为是脉冲SEP来源的环境，以及真实太阳在多大程度上满足这些条件。 显示英文摘要

摘要： We outline and discuss a model for the enhanced abundances of trans-Fe elements in impulsive Solar Energetic Particle (SEP) events, where large mass dependent abundance enhancements are frequently seen. It comes about as a variation of the ponderomotive force model for the First Ionization Potential (FIP) Effect, i.e. the increase in coronal abundance of elements like Fe, Mg, and Si that are ionized in the solar chromosphere relative to those that are neutral. In this way, the fractionation region is placed in the chromosphere, and is connected to the solar envelope allowing the huge abundance variations to occur, that might otherwise be problematic with a coronal fractionation site. The principal mechanism behind the mass-independent FIP fractionation becoming the mass dependent impulsive SEP fractionation is the suppression of acoustic waves in the chromosphere. The ponderomotive force causing the fractionation must be due to torsional Alfven waves, which couple much less effectively to slow modes than do shear waves, and upward propagating acoustic waves deriving from photospheric convection must be effectively mode converted to fast modes at the chromospheric layer where Alfven and sound speeds are equal, and subsequently totally internally reflected. We further discuss observations of the environments thought to be the source of impulsive SEPs, and the extent to which the real Sun might meet these conditions.