Study of the effect of shell closure on the nuclear dissipation

Neutron multiplicity measurements are carried out for the 19 F + 194,196,198 Pt systems at excitation energy range of 48 to 67.5 MeV. Out of these three compound nuclei (CN) 217 Fr, 215 Fr and 213 Fr, one of the CN ( 213 Fr) has neutron shell closure (N C =126). Experimentally obtained neutron multiplicities are compared with the standard statistical model predictions. It has been observed that the standard statistical model under-predicts the experimental pre-scission neutron multiplicities values. Also the comparison of pre-scission neutron multiplicities for different compound nuclei (CN) indicates the signature of shell effects on nuclear dissipation, which results in the lowering of the pre-scission neutron multiplicities.