Group of type III bursts and its associated spikes

A group of type III bursts in solar radio bursts, observed with the 2.6-3.8 GHz spectrometer of the Beijing Astronomical Observatory on April 15 1998, is selected and analyzed. The type III bursts are associated with a large number of spikes, which have been recorded by the spectrometer at high temp oral resolution (8 ms). We report the observational characteristics of the type III bursts and the corresponding spikes including duration, frequency bandwidth, drift rate and quasi-periodicity. Afterwards we discuss the spac e scale, the brightness temperature and the magnetic field strength at the emission source region. Finally we investigate the mechanism which would ca use the quasi-periodicity of the type III bursts and the short time scale o f the spikes theoretically. It is suggested that the type III bursts and th e spikes differ clearly between their source regions in the space scale, th e brightness temperature, the magnetic field strength and the magnetic stru cture.