Observations of Temporal Fine Structures in Solar Millimeterwave Bursts

本研究的目的是在观测上估计太阳耀斑中粒子加速的时间尺度。1990 ~ 1992年，利用35 ghz偏振光计对21次太阳活动进行了观测。这些事件是在35GHz的磁通密度大于2500 sfu的条件下选择的。数据分析的主要结果如下：1。在时间剖面中，峰到峰的时间间隔从0.5秒到500秒不等。只有7%的峰间时间间隔小于1 s。每个事件的平均峰到峰时间间隔与事件的上升时间或衰减时间成正比。上述观测结果表明，大型太阳耀斑中粒子加速的时间尺度大多在1 ~ 100 s之间，其中最快速的时间尺度约为0.5 s。

The objective of this research is to estimate observationally the time scale of particle acceleration in solar flares. We observed 21 events with the 35-GHz Polarimeter for solar activity monitor during from 1990 through 1992. These events were chosen under the criterion that flux density at 35GHz was greater than 2500 sfu.Main results of analyses of the data are as follows.1. Peak-to-peak time intervals in time profiles ranges from 0.5 to 500 s. Only 7 % shows peak-to-peak time intervals less than 1 s.2. Average peak-to peak time interval for each event is proportional to the rise time or the decay time of the event.3. The above observational results suggest that the time scale of particle acceleration in large solar flares ranges from 1 s to 100 s fot most events, and that the most rapid time scale is about 0.5 s.