Fig. 11

Transitions of number of the resonant electrons and trapping probability in case 1 (500 keV-60°), case 2 (2.1 MeV-80°), and case 3 (5.7 MeV-86°). a In case 1, out of 360 electrons initially in resonance with the chorus wave, only 304 electrons are entrapped by the first subpacket (packet 1), and 56 electrons are shortly detrapped and get off resonance. Hence the trapping probability of packet 1 is 84.4%. In the same manner, 260 electrons out of the 304 electrons are consecutively entrapped by packet 2. Hence the trapping probability of packet 2 is 85.5%. The probability of successive trapping (trapping by more than one subpackets) in case 1 is 72.2%. b Similarly, the trapping probabilities for each packet in case 2 are shown in the table, and the probability of successive trapping is 45.8%. c The trapping probabilities for each packet in case 3 are shown in the table. The probability of successive trapping in case 3 is 55.3%. It can be seen that the probability of successive trapping is higher in the lower energy case (RTA acceleration case) such as case 1