T. Beck

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.

Core-coupled states and split proton-neutron quasiparticle multiplets in 122-126Ag

Neutron-rich silver isotopes were populated in the fragmentation of a Xe-136 beam and the relativistic fission of U-238. The fragments were mass analyzed with the GSI Fragment Separator and subsequently implanted into a passive stopper. Isomeric transitions were detected by 105 high-purity germanium detectors. Eight isomeric states were observed in Ag122-126 nuclei. The level schemes of Ag-122,Ag-123,Ag-125 were revised and extended with isomeric transitions being observed for the first time. The excited states in the odd-mass silver isotopes are interpreted as core-coupled states. The isomeric states in the even-mass silver isotopes are discussed in the framework of the proton-neutron split multiplets. The results of shell-model calculations, performed for the most neutron-rich silver nuclei are compared to the experimental data. DOI: 10.1103/PhysRevC.87.034308 (Less)

Relativistic coulomb excitation of neutron-rich 54,56,58Cr

The first excited 2+ states in neutron-rich 54,56,58Cr were populated by relativistic Coulomb excitation and B (E2, 2 1 + → 0+) values were determined for 56Cr and 58Cr. The B(E2) values show a minimum for 56Cr providing evidence for a subshell closure at N=32.