C. Chandler

Spectroscopy of Nuclei Approaching the Proton Drip-line Using a Secondary-fragmentation Technique with the RISING Detector Array

An experiment utilizing a double fragmentation reaction was performed to study isobaric analogue states in A similar to 50 nuclei approaching the proton drip-line. gamma-ray spectroscopy will be used to identify excited states in the neutron-deficient nuclei produced in the second fragmentation reaction. Excited state level schemes will be obtained, through comparison with states in their well-known mirror partners, along with information on Coulomb effects through measurements of the Coulomb energy differences between isobaric analogue excited states. The validity of isospin symmetry for nuclei approaching the proton drip-line can also be investigated and the information gained will aid in testing and improving fp shell model calculations. The analysis of the collected data is at a preliminary stage and current status of this work is reported.

First Observation Of Excited States In The T = -1, Odd-Odd Nucleus 48 Mn

Gamma decays depopulating excited states in the odd‐odd N=Z − 2 nucleus 48Mn have been observed for the first time. The yrast band has been built up from the 4+ ground state to 13+, just shy of the expected band termination at 15+. When compared with its mirror, 48V, the Coulomb energy differences are unlike any other previously measured which, until now, have been dominated by a sudden rotational alignment. Such an alignment is expected to be blocked in these odd‐odd nuclei and calculations not only confirm this, but also infer that any Coulomb difference is mostly due to monopole effects.

Indication for superallowed Fermi decay from the

The heavy odd-odd N=Z nuclei {sup 78}Y,{sup 82}Nb,{sup 86}Tc have been produced at GANIL by fragmentation of a 60 MeV/u {sup 92}Mo beam on a natural nickel target. Their lifetime have been measured for the first time, using the identification-implantation and subsequent time correlated {beta} counting technique at the LISE spectrometer. The obtained half-lives for {sup 78}Y,{sup 82}Nb,{sup 86}Tc are consistent with the microscopic predictions. These nuclei are good candidates to extend the mass range for the V{sub ud} matrix element evaluation and our experimental results highlight the interest of further investigation of their excited states and {beta} decay schemes as a function of isospin. {copyright} {ital 1998 American Institute of Physics.}

Indication for superallowed Fermi decay from the N=Z nuclei {sup 78}Y,{sup 82}Nb,{sup 86}Tc

The heavy odd-odd N=Z nuclei {sup 78}Y,{sup 82}Nb,{sup 86}Tc have been produced at GANIL by fragmentation of a 60 MeV/u {sup 92}Mo beam on a natural nickel target. Their lifetime have been measured for the first time, using the identification-implantation and subsequent time correlated {beta} counting technique at the LISE spectrometer. The obtained half-lives for {sup 78}Y,{sup 82}Nb,{sup 86}Tc are consistent with the microscopic predictions. These nuclei are good candidates to extend the mass range for the V{sub ud} matrix element evaluation and our experimental results highlight the interest of further investigation of their excited states and {beta} decay schemes as a function of isospin. {copyright} {ital 1998 American Institute of Physics.}