标题： 太阳高能粒子从非连接源传输中的垂直扩散：重新审视反流粒子束 显示英文标题

标题： Perpendicular Diffusion in the Transport of Solar Energetic Particles from Unconnected Sources: The Counter-streaming Particle Beams Revisited

摘要： 在一些太阳高能粒子（SEP）事件中，在开始阶段观测到一个反向流粒子束，在约90度投掷角附近出现流量的深陷区域。 该有趣现象在研究群体中有两种不同的解释。 一种解释引入了观测者之外存在外部反射边界或磁镜的假设。 另一种解释则考虑了垂直扩散效应对星際空间中SEP传输过程的影响。 本文重新探讨了在SEP事件中观测到的反向流粒子束问题，并讨论了导致该现象形成的可能机制。 我们澄清了一些先前工作中的结果。 显示英文摘要

摘要： In some solar energetic particle (SEP) events, a counter-streaming particle beam with a deep depression of flux near 90 degrees pitch angle during the beginning phase is observed. Two different interpretations exist in the community to explain this interesting phenomenon. One explanation invokes the hypothesis of an outer reflecting boundary or a magnetic mirror beyond the observer. The other one considers the effect of the perpendicular diffusion on the transport process of SEPs in the interplanetary space. In this work, we revisit the problem of the counter-streaming particle beams observed in SEP events and discuss the possible mechanisms responsible for the formation of this phenomenon. We clarify some results in previous works.