H. C. Griffin

Cold (neutronless)αternary fission of252Cf

The phenomenon of cold (neutronless) alpha ternary fission in spontaneous fission of {sup 252}Cf was experimentally observed by triple gamma coincidence technique with Gammasphere with 72 gamma-ray detectors. Correlated pairs of {sub 36}Kr-{sub 60}Nd, {sub 38}Sr-{sub 58}Ce, {sub 40}Zr-{sub 56}Ba, {sub 42}Mo-{sub 54}Xe, {sub 44}Ru-{sub 52}Te, and {sub 46}Pd-{sub 50}Sn were observed to be associated with {alpha} ternary fission of {sup 252}Cf. Yields of cold {alpha} ternary fission were extracted. {copyright} {ital 1998} {ital The American Physical Society}

Possible octupole correlation in {sup 147}Pr and {pi}h{sub 11/2} bands in {sup 149,151}Pr

Neutron-rich {sup 147,149,151}Pr nuclei, produced in the spontaneous fission of {sup 252}Cf, were studied using the Gammasphere array. Possible parity doublets in {sup 147}Pr with N=88 and {pi}h{sub 11/2} bands in {sup 149,151}Pr are proposed. These new data on the level structures of odd Pr isotopes suggest that octupole correlations may also be present in the neutron-rich {sub 59}{sup 147}Pr{sub 88} nucleus such as those observed in {sub 58}{sup 146}Ce{sub 88}, and also that the h{sub 11/2} bands in the {sup 149,151}Pr track in energy the yrast bands in {sup 148,150}Ce. The backbending related to the breaking of the neutron i{sub 13/2} pair is observed at {Dirac_h}{omega}{approx}0.27 (MeV) for the proton h{sub 11/2} band of {sup 149}Pr.

Identification of the

From an experiment with Gammasphere and a 252C spontaneous fission source, two bands with signatures -i and +i are identified in 153Nd Also several new transitions in 149Nd are observed for the first time. The band with signature -i in 153Nd shows no back bending, similar to the one observed in 161Er. The signature splitting observed in the ground band of 153Nd is similar to the ones observed in N=93 isotones in this mass region. In 149Nd the new transitions are placed into a band with a proposed configuration of .

\nu_{\frac 32}-[521]

The phenomenon of cold (neutronless) alpha ternary fission in spontaneous fission of {sup 252}Cf was experimentally observed by triple gamma coincidence technique with Gammasphere with 72 gamma-ray detectors. Correlated pairs of {sub 36}Kr-{sub 60}Nd, {sub 38}Sr-{sub 58}Ce, {sub 40}Zr-{sub 56}Ba, {sub 42}Mo-{sub 54}Xe, {sub 44}Ru-{sub 52}Te, and {sub 46}Pd-{sub 50}Sn were observed to be associated with {alpha} ternary fission of {sup 252}Cf. Yields of cold {alpha} ternary fission were extracted. {copyright} {ital 1998} {ital The American Physical Society}

Band in 153Nd and the γ-Transitions in 149Nd

The phenomenon of cold (neutronless) alpha ternary fission in spontaneous fission of {sup 252}Cf was experimentally observed by triple gamma coincidence technique with Gammasphere with 72 gamma-ray detectors. Correlated pairs of {sub 36}Kr-{sub 60}Nd, {sub 38}Sr-{sub 58}Ce, {sub 40}Zr-{sub 56}Ba, {sub 42}Mo-{sub 54}Xe, {sub 44}Ru-{sub 52}Te, and {sub 46}Pd-{sub 50}Sn were observed to be associated with {alpha} ternary fission of {sup 252}Cf. Yields of cold {alpha} ternary fission were extracted. {copyright} {ital 1998} {ital The American Physical Society}

Cold (neutronless) {alpha} ternary fission of {sup 252}Cf

Low-emission barriers and large subbarrier anisotropies in the α-particle decay, with respect to the spin direction, of Sn and rare-earth compound nuclei are examined in the light of recent calculations incorporating deformation. For the rare-earth systems deformation which increases with spin is necessary to explain the data. Energy spectra and angular correlations of evaporated protons from the 52Cr(34S, 2p2n)82Sr reaction were measured in coincidence with discrete transitions. Large changes in the shape of the proton spectra were observed when high-spin states in different rotational bands are populated. These effects cannot be explained by phase space arguments that do not include explicitly structure in the deexcitation process. They are interpreted as resulting from near-yrast to near-yrast stretched proton emission, which preferentially populates the yrast band by subbarrier protons.