Measurement of Fission Fragment Anisotropies for Proton-Induced Fission of Two Pre-Actinide Nuclei at Several Energies

Abstract

The angular distribution of fission fragments has been measured for proton-induced fission of 197 Au and 209 Bi nuclei at several energies between 25 and 30 MeV using surface-barrier detectors. The measured anisotropies are found to be in agreement with the predictions of the standard saddle-point statistical model. The measured anisotropies for neither of the nuclei show any anomalous behavior as a function of both energy and entrance channel mass asymmetry. The fission cross sections of 197 Au and 209 Bi nuclei were also measured and compared with that of the previous works.

Calculation of spin distribution for several fission reaction systems induced by nucleons and heavy ions

“…In this method, the quantity I 2 is considered as a linear equation in terms of the projectile energy in the center-of-mass framework [2], then, having found the values of B f , E R , and eff T h 2 and using the experimental data for the angular anisotropy of fission fragments [3][4][5][6][7][8][9][10][11][12], we could obtain I 2 by comparing the experimental data of angular anisotropy as well as the prediction of SSPSM. In the present work, we determined the values of I 2 for 18 systems undergoing induced fission with heavy ion as well as those of two systems undergoing induced fission with nucleon.…”

“…Due to the low weight of projectile, rotational energy (E R ) can be neglected. Given all necessary data including B f and eff h 2 [12], we can determine the compound nucleus spin distribution through comparing the experimental data for angular anisotropy of fission fragments [12] as well as the prediction of SSPSM. In this work, we have determined the values of compound nucleus spin distribution in terms of E c.m.…”