A MODEL FOR SIMPLE SPIKES OF SOLAR HARD X-RAY BURSTS

Based on the time profiles of 103 strong hard X-ray burst events (their peak rattes are more then₆₀₀₀ c/s according to Hard X-ray Burst Spectrometer) observed by GRS (γ-ray Spectrometer) aboard on SMM (Solar Maximum Mission) satellite from Feb. 1980 to Dec. 1982, it is identified that 24 of them contain the simple impulsive spikes characterized by large amplitude and smooth time profile. The statistical results of the 24 simple spikes in 54-100keVenerge range show that: 1) the spike time profiles' rising slopes correlate well with the falling slopes, and correlation coefficient is about 0.80. 2) rising slope is slightly larger than falling slope, and their averge ratio is about 1.37. Meanwhile, a standard spike is used for quantitative analyzing, whose rising phase characteristic time is about 12.7s and falling phase is 17.4s according to the mean value of the slopes. It then is concluded that the acceleration region continously and symmetrically inject energetic electrons into the loop, and trapplus-precipitation model in strong whistler scattering limit is a proper hard X-ray emission model.