报告题目：Statistical Analysis of Interplanetary Magnetic Field Path Lengths from Solar Energetic Electron Events Observed by WIND

　　报告人：赵璐璐

　　报告人简介：美国佛罗里达理工大学研究员，2009年取得北京大学取得物理学学士学位，2015年取得美国阿拉巴马大学物理学博士学位，主要从事日冕和星际空间中太阳能量粒子的加速和输运的研究。

　　报告摘要：We calculate the interplanetary magnetic field path lengths traveled by electrons in solar electron events detected by the WIND 3DP instrument from 1994 to 2016. The velocity dispersion analysis method is applied for electrons at energies of ～27–310 keV. Previous velocity dispersion analyses employ the onset times, which are often affected by instrumental effects and the pre-existing background flux, leading to large uncertainties. We propose a new method here. Instead of using the peak or onset time, we apply the velocity dispersion analysis to the times that correspond to the rising phase of the fluxes that are a fraction, η, of the peak flux. We perform statistical analysis on selected events whose calculated path lengths have uncertainties smaller than 0.1 au. The mean and standard deviation, (μ, σ), of the calculated path lengths corresponding to η = 3/4, 1/2, and 1/3 of the peak flux is (1.17 au, 0.17 au), (1.11 au, 0.14 au), and (1.06 au, 0.15 au). The distribution of the calculated path lengths is also well fitted by a Gaussian distribution for the η = 3/4 and 1/3 cases. These results suggest that in these electron events the interplanetary magnetic field topology is close to the nominal Parker spiral, with little field line meandering. Our results have important implications for particles’ perpendicular diffusion.

　　报告时间：2019年11月12日 （星期二）下午2:30

　　报告地点：仙林园区3-302会议室

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