F. Maréchal

Beta decay and structure of exotic nuclei in the mass regions N=Z, A ~ 70 and near the N=20 closed shell

This paper describes two beta decay experiments performed at the CERN/ISOLDE mass separator. The structure of 74Kr has been studied using a total absorption g spectrometer (TAgS). The measured Gamow-Teller strength is presented and compared to HFBCS+QRPA calculations. The 33Na decay is also presented. The structure of the 33Mg daughter nucleus is compared to shell-model calculations, showing for the first time an inversion of states in the A~35 mass region.

Elastic and inelastic scattering of protons on 38S in inverse kinematics

Abstract Elastic and inelastic scattering of protons on unstable 38 S nuclei has been measured in inverse kinematics by using a 38 S secondary beam at 39 MeV/nucleon. The excitation energy spectrum is measured up to 5 MeV. The first 2 + state is seen at 1.2 MeV excitation energy, and strength at around 3–5 MeV is also observed. Angular distributions for inelastic and elastic scattering are shown and compared to optical potential and folding model calculations. The preliminary β 2 value extracted for the first 2 + state is 0.38±0.05.

STRUCTURE OF THE HEAVY CA ISOTOPES AND EFFECTIVE INTERACTION IN THE SD-FP SHELL

p decays of the neutron-rich nuclei 51,52,53K have been used to populate bound and unbound levels in 50,51,52,53Ca. y r a y spectroscopy as well as P-delayed neutron spectroscopy by time of flight were carried out to obtain a detailed decay scheme to levels in 53Ca, 52Ca, 51Ca and 50Ca. A half-life of 1 1 6 f 6 ms was deduced and new PI, and Pzn delayed neutron emission probabilities have also been determined for 52K. A total of 11 and 3 new y transitions have been observed in the decay of 52K and 53K, respectively. The low-lying level structure of 52Ca is compared to shell-model calculations. Implications of these results on the determination of the Y-Y interaction in the fp shell are discussed.

Deformation of theN=ZNucleusSr76usingβ-Decay Studies

A novel method of deducing the deformation of the N=Z nucleus 76Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its beta decay with the results of quasi-random-phase approximation calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent way. The measurement has been carried out with a large total absorption gamma spectrometer, Lucrecia, newly installed at CERN-ISOLDE.

Deformation of the N = Z nucleus76Sr using β-decay studies

A novel method of deducing the deformation of the N=Z nucleus 76Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its beta decay with the results of quasi-random-phase approximation calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent way. The measurement has been carried out with a large total absorption gamma spectrometer, Lucrecia, newly installed at CERN-ISOLDE.

A new Total Absorption Spectrometer for the study of exotic nuclei at the CERN/ISOLDE mass separator

We report here on a new Total Absorption Spectrometer dedicated to the study of exotic nuclei, presently installed at the CERN/ISOLDE mass separator.