Technique for Resolving Low-lying Isomers in the Experimental Storage Ring (ESR) and the Occurrence of an Isomeric State in 192Re

A recent experiment using projectile fragmentation of a 197Au beam on a 9Be target, combined with the fragment recoil separator and experimental storage ring at ring at GSI, has uncovered an isomeric state in 192Re at 267(10) keV with a half-life of ∼6

Recent Precision Experiments with Exotic Nuclei Produced with Uranium Projectiles and Experimental Prospects at Fair

Precision experiments with relativistic fragments separated in-flight require special experimentalmethods to overcome the inherent large emittance from the creation in nuclear reactions and atomic interactions in matter. At GSI relativistic exotic nuclei have been produced via uranium projectile fragmentation and fission and investigated with the inflight separator FRS directly, or in combination with either the storage-cooler ring ESR or the FRS Ion Catcher. 1000 A·MeV 238U ions were used to create 60 new neutron-rich isotopes separated and identified with the FRS to measure their production cross sections. In another experimental campaign the fragments were separated in flight and injected into the storage-cooler ring ESR for accurate mass and lifetime measurements. In these experimentswe have obtained accurate new mass values analyzed via a novel method which has reduced the systematic errors for both Schottky Mass Spectrometry (SMS) and for Isochronous Mass Spectrometry (IMS). Pioneering experiments have been carried out with the FRS Ion Catcher consisting of three experimental components, the dispersive magnetic system of the FRS with a monoenergetic and a homogeneous degrader, a cryogenic stopping cell filled with pure helium and a multiple-reflection time-of flight mass separator. The FRS Ion Catcher enables high precision spectroscopy experiments with eV to keV exotic nuclides. Results from these different FRS experiments are presented in this overview together with prospects for the next-generation facility Super-FRS. The novel features of the Super-FRS compared with the present FRS will be discussed in addition

Direct mass measurements around A=46 at SHIPTRAP

International audienceOn-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. Fusion-evaporation reactions were used to produce the nuclides of interest which were transferred to the traps as singly or doubly charged ions. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region were determined with relative uncertainties of about 7.10(-8), nine of them for the first time. The data entered the Atomic Mass Evaluation and showed good agreement with previous results. A detailed description of the analysis and mass evaluation procedure is presented

Discovery of Highly Excited Long-Lived Isomers in Neutron-Rich Hafnium and Tantalum Isotopes through Direct Mass Measurements

A study of cooled Au197 projectile-fragmentation products has been performed with a storage ring. This has enabled metastable nuclear excitations with energies up to 3 MeV, and half-lives extending to minutes or longer, to be identified in the neutron-rich nuclides Hf183,184,186 and Ta186,187. The results support the prediction of a strongly favored isomer region near neutron number 116

Long-lived isomers in neutron-rich Z=72 76 nuclides

A study of neutron-rich isotopes in the A=185 region of the nuclear chart has uncovered long-lived (>1s) isomers in several isotopes of hafnium, tantalum, tungsten, rhenium, and osmium. The region was accessed via the use of projectile fragmentation wit