Jolie A. Cizewski

Direct reaction measurements with a 132Sn radioactive ion beam

The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of {sup 132}Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p{sub 1/2} state expected above the N=82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus {sup 208}Pb.

Level Density and Strength Function from Quasicontinuous Decay of Superdeformed Excitations in Lead Nuclei

The shape of the spectrum associated with the quasicontinuous (QC) decay of superdeformed rotational bands in even- and odd-mass Pb isotopes is sensitive to the gap in level density at finite temperature and angular momentum at normal deformations. This gap in level density was deduced to be {approx}0.95 MeV at 6{Dirac_h} for {sup 194}Pb and {approx}0.4 MeV at 10{Dirac_h} for {sup 192}Pb, while the shape of the QC spectrum for {sup 195}Pb is consistent with no gap in the level density at about 11{Dirac_h}.