Gradual solar energetic particle (SEP) events at 1 AU are produced by coronal/interplanetary shocks driven by coronal mass ejections (CMEs). Fast (vCME 900 km s-1) CMEs might produce stronger shocks in solar slow-wind regions, where the flow and fast-mode MHD wave speeds are low, than in fast-wind regions, where those speeds are much higher. At 1 AU the O+7/O+6 ratios distinguish between those two kinds of wind streams. We use the 20 MeV proton event intensities from the EPACT instrument on Wind, the associated CMEs observed with the LASCO coronagraph on SOHO, and the ACE SWICS solar wind values of O+7/O+6 to look for variations of peak SEP intensities as a function of O+7/O+6. No significant dependence of the SEP intensities on O+7/O+6 is found for either poorly connected or well-connected CME source regions or for different CME speed ranges. However, in the 3 yr study period we find only five cases of SEP events in fast wind, defined by regions of O+7/O+6 0.15. We suggest that in coronal holes SEP acceleration may take place only in the plume regions, where the flow and Alfvén speeds are low. A broad range of angular widths are associated with fast (vCME ≥ 900 km s-1) CMEs, but we find that no fast CMEs with widths less than 60° are associated with SEP events. On the other hand, nearly all fast halo CMEs are associated with SEP events. Thus, the CME widths are more important in SEP production than previously thought, but the speed of the solar wind source regions in which SEPs are produced may not be a factor.
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机译：1 AU处的逐步太阳高能粒子（SEP）事件是由日冕质量抛射（CME）驱动的日冕/行星际冲击产生的。快速的（vCME 900 km s-1）CME在太阳慢风区域（流动和快速模式MHD波速较低）可能比强风区域（其速度高得多）产生更强的冲击。在1 AU时，O + 7 / O + 6比率可区分这两种风流。我们使用EPACT仪器在Wind上的20 MeV质子事件强度，在LASCO日冕仪上在SOHO上观察到的相关CME和O + 7 / O + 6的ACE SWICS太阳风值来寻找SEP峰值强度O + 7 / O + 6的功能对于连接不良或连接良好的CME源区域或不同的CME速度范围，未发现SEP强度对O + 7 / O + 6的显着依赖性。但是，在3年的研究期内，我们发现只有5例发生在快速风中的SEP事件，由O + 7 / O + 6 <0.15的区域定义。我们建议在冠状孔中，SEP加速只能在气流和Alfvén速度较低的羽状区域中发生。快速（vCME≥900 km s-1）CME与大范围的角宽度相关，但我们发现没有小于60°的快速CME与SEP事件相关。另一方面，几乎所有的快速光晕CME都与SEP事件相关。因此，CME宽度在SEP生产中比以前认为的更为重要，但是生产SEP的太阳风源区域的速度可能不是一个因素。
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