Dependence of fragment angular momentum on nature of fissioning nuclei (Preprint No. NR-5)

In order to investigate the effects of fragment nuclear structure and the nature of fissioning nuclei on scission configuration, independent isomeric yield ratios of 132I have been determined radiochemically in 235U (nsub(th),f) and 252Cf (S.F.). The fragment angular momenta (B) for 132I have been deduced from independent isomeric yield ratios using spin dependent statistical model analysis. It is observed that B-value for 132I is higher than 134I (determined earlier from this laboratory) in both the fissioning nuclei. This is due to the proximity of the spherical 82n shell in the fragment for the fission product 134I. B-value for both 132I and 134I are seen to be higher in 252Cf (S.F.) than in 235U (nsub(th),f). This may be d ue to different nature of fissioning nuclei from the point of view of excitation energy and/or dynamics (i.e. descent from saddle to scission) because of which fragment deformation (at scission) and thus angular momentum are different. (author). 6 refs