Threefold Fragmentation in Hot.Nuclei with Medium Masses
- Received Date: 1995-06-15
Abstract: The threefold massive fragment in hot nuclei with medium mass number has been measured in 40Ar+115In, 103Rh, and 93Nb reactions at 25MeV/u. The fragments emitted at angles larger than 32° are detected by ten parallel plate position-sensitive avalanche counters (PPAC), each with an area of 25×20cm2. The total kinetic energies (TKE),the yield ratio P32 of the threefold fragmentation to Hssion,and the distributions of the fragment mass, velocity, and relative angle,etc., are obtained. From the mass ratio of the fragments, a simple empirical expression is deduced. By analyzing their angular correlation function with a simple space-time model, the time difference between two scission points in the threefold process in the Ar+In reaction system is derived. A systematics of P32 versus Z2/A for hot nuclei is observed.