THE HIGH-ENERGY IMPULSIVE GROUND-LEVEL ENHANCEMENT
THE HIGH-ENERGY IMPULSIVE GROUND-LEVEL ENHANCEMENT
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DOI：
10.1088/0004-637x/761/2/101
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发表时间：
2012-11
期刊：
影响因子：
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通讯作者：
Ken McCracken;H. Moraal;M. Shea
中科院分区：
文献类型：
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作者：
Ken McCracken;H. Moraal;M. Shea
我们研究了短寿命（平均持续时间21分钟）、高度各向异性的宇宙射线脉冲，这些脉冲构成了10个大型地面增强（GLEs）的第一阶段，并扩展到5-20 GV范围内的刚度。我们为这类太阳-能量-粒子（SEP）事件的任何假定的加速机制提供了一组必须满足的约束条件。脉冲通常具有非常短的上升时间（三到五分钟），并且在另外三到五分钟内表现出强度从最大值急剧下降50%到70%的显著特征。上升相和下降相都表现出速度色散，这表明在190 MeV的伽马射线爆发范围内存在具有刚性的粒子，这表明在SEP脉冲离开地球之前，新加速的SEP撞击了色球层中的高密度物质。这项研究是基于历史记录中71个gle的更新档案，现在可供公众使用。
We have studied short-lived (21 minute average duration), highly anisotropic pulses of cosmic rays that constitute the first phase of 10 large ground-level enhancements (GLEs), and which extend to rigidities in the range 5–20 GV. We provide a set of constraints that must be met by any putative acceleration mechanism for this type of solar-energetic-particle (SEP) event. The pulses usually have very short rise-times (three to five minutes) at all rigidities, and exhibit the remarkable feature that the intensity drops precipitously by 50% to 70% from the maximum within another three to five minutes. Both the rising and falling phases exhibit velocity dispersion, which indicates that there are particles with rigidities in the range 1 90 MeV gamma-ray bursts, indicating that freshly accelerated SEPs had impinged on higher-density matter in the chromosphere prior to the departure of the SEP pulse for Earth. This study was based on an updated archive of the 71 GLEs in the historic record, which is now available for public use.