Photofission of Bi at intermediate energies

Haba, Hiromitsu; Kasaoka, Makoto*; Igarashi, Manabu*; Washiyama, Koshin*; Matsumura, Hiroshi*; Oura, Yasuji*; Shibata, Seiichi*; Sakamoto, Ko*; Furukawa, Michiaki*; Fujiwara, Ichiro*

The reaction yields of 63 radionuclides with the mass number A = 56-135 produced in the photofission of Bi by bremsstrahlung of end-point energies (E) from 450 to 1100 MeV have been measured using a catcher foil technique. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Z) expressed by Z = RA + S, and with the A-independent FWHME. The charge distribution parameters R, S and FWHM were independent of E above 600 MeV. The weighted mean values at E 600 MeV were R = 0.421 0.001, S = 0.6 0.1 and FWHM = 2.1 0.1 charge unit (c.u.). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable mass A of 96 1 mass unit (m.u.) and the width FWHM of 33 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for Au based on the results of calculations using PICA3/GEM.