标题： 太阳高能粒子的元素丰度和源等离子体温度 显示英文标题

标题： Element Abundances and Source Plasma Temperatures of Solar Energetic Particles

摘要： 三十年前，布伦纳曼和斯通观察到，在大型太阳高能粒子（SEP）事件中，元素丰度的增强或抑制随元素的质量电荷比 A/Q 的幂次变化。由于加速或传输过程中的 Q 可能依赖于源等离子体温度 T，因此元素增强的模式可以提供一个最佳拟合的 T 测量值。我们称之为“富 3He”或“冲动型”的小型 SEP 事件，相对于日冕丰度，其平均增强相对 A/Q 的 3.6 次方上升，对于 (76<=Z<=82)/O 达到约 1000 倍，并且温度范围在 2-4 MK。 这种加速被认为发生在太阳耀斑和喷流开放磁场线上的磁重联岛中。 最近发现，大冲击加速的“渐进型”SEP 事件具有广泛的源等离子体温度；69% 的温度低于 1.6 MK，而 24% 的温度约为 3 MK，后者表明存在含有残留冲动超热离子的种子群体。 然而，冲动 SEP 事件的非热方差（约 30%）超过了约 3 MK 渐进事件的非热方差（约 10%），因此必须将多个小冲动事件与周围等离子体平均在一起，以形成这些事件中冲击加速的种子群体。 显示英文摘要

摘要： Thirty years ago Breneman and Stone observed that the enhancement or suppression of element abundances in large solar energetic-particle (SEP) events varies as a power of the mass-to-charge ratio, A/Q, of the elements. Since Q during acceleration or transport may depend upon the source plasma temperature T, the pattern of element enhancements can provide a best-fit measure of T. The small SEP events we call 3He-rich or "impulsive" show average enhancements, relative to coronal abundances, rising as the 3.6 power of A/Q to a factor of ~1000 for (76<=Z<=82)/O and temperature in the range 2-4 MK. This acceleration is believed to occur in islands of magnetic reconnection on open field lines in solar flares and jets. It has been recently found that the large shock-accelerated "gradual" SEP events have a broad range of source plasma temperatures; 69% have coronal temperatures of T < 1.6 MK, while 24% have T ~ 3 MK, the latter suggesting a seed population containing residual impulsive suprathermal ions. Most of the large event-to-event abundance variations and their time variation are largely explained by variations in T magnified by A/Q-dependent fractionation during transport. However, the non-thermal variance of impulsive SEP events (~30%) exceeds that of the ~3 MK gradual events (~10%) so that several small impulsive events must be averaged together with the ambient plasma to form the seed population for shock acceleration in these events.