Emission order of light particles and light fragments from hot nuclei followed by binary fission
Zhi Yong He - Gen Ming Jin - Zu Yu Li - Li Min Duan - Guang Xi Dai - Bao Guo Zhang - He Yu Wu - Wan Xin Wen - Yu Jin Qi - Qing Zheng Luo - Su Fang Wang
Institute of Modern Physics, Chinese Academy of Sciences, P. O. Box 31, Lanzhou 730000, Gansu Province, People's Republic of China
Received: 3 June 1997 / Revised version: 23 July 1997
Emission orders of light charged particles and Li fragments from highly excited fissioning nuclei in the reaction of 40Ar+197Au at Ebeam/A=25 MeV have been studied by measuring difference velocity distributions of two correlated particles at small relative angles in coincidence with two fission fragments. By comparing the data with three-body trajectory calculations, we found that high velocity deuterons are emitted prior to high velocity Li fragments but low velocity deuterons are emitted after low velocity Li fragments. On the other hand, no preferential emission was observed among light particles, such as protons and deuterons. Furthermore, the emission orders are found to depend only weakly on the mass asymmetry of fission fragments.
25.70.z Low and intermediate energy heavy ion reactions - 25.70.Lm Strongly damped collisions - 25.70.Pq Multifragment emission and correlations