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Produced in the reaction 48Ca+243Am, thirty correlated α-decay chains were observed in an experiment conducted at the GSI Helmholzzentrum für Schwerionenforschung, Darmstadt, Germany. The decay chains are basically consistent with previous findings and are considered to originate from isotopes of element 115 with mass numbers 287, 288, and 289. A set-up aiming specifically for high-resolution charged particle and photon coincidence spectroscopy was placed behind the gas-filled separator TASCA. For the first time, γ rays as well as X-ray candidates were observed in prompt coincidence with the α-decay chains of element 115.

Total absorption spectroscopy is a technique that helps obtain reliable β-feeding patterns of complex decays important for nuclear structure and astrophysics modeling as well as decay heat analysis in nuclear reactors. The need for improved measurements of β-feeding patterns from fission decay products has come to the forefront of experiments that use nuclear reactors as a source of antineutrinos. Here we present more detailed results, in particular the β-decay measurements of 96gsY, and demonstrate the impact of the β-delayed γ multiplicity on the overall efficiency of Modular Total Absorption Spectrometer used at Oak Ridge National Laboratory to study the decays of fission products abundant during a nuclear fuel cycle. [ABSTRACT FROM AUTHOR]

In an experiment at the HRIBF, Oak Ridge National Laboratory, USA, we have investigated excited states in 86Se populated in the beta-decay of 86As. Several new transitions were identified. Preliminary results are presented. [ABSTRACT FROM AUTHOR]

Recently, a unique detector system for beta-delayed neutron spectroscopy, Hybrid-3Hen, was constructed and used in an experiment. This detector is a modification of the neutron detector 3Hen array, which uses ³He-filled tubes at 10 atm and high density polyethylene moderator. In Hybrid-3Hen the gamma-ray detection capability was implemented by adding two large HPGe clover-type detectors from the CLARION/CARDS array. This modification of 3Hen enabled efficient studies of beta-delayed neutron emission by using neutron-gamma coincidences. The system is equipped with full-digital readout for easy implementation of the slow and fast coincidences between various parts of the entire detection system. This new array was used in measurements at the Holifield Radioactive Ion Beam Facility and proven to be an essential tool to measure the large beta delayed two neutron emission branching ratio from the exotic isotope 86Ga. [ABSTRACT FROM AUTHOR]

A Modular Total Absorption Spectrometer (MTAS) has been recently constructed and commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at the Oak Ridge National Laboratory (ORNL). The main goal of MTAS is to determine the true beta-decay feeding and following gamma radiation pattern for the decays of fission products. In this contribution, we would like to present the results of the measurement of 86Br. The preliminary analysis yields an average energy of emitted γ-radiation of about 4110 keV. It represents an increase of over 26% (850 keV), when compared to the average EM energies deduced using the ENSDF database. [ABSTRACT FROM AUTHOR]

The measurement of the ß-decay scheme of 85Ga triggered questions on the properties of the low-lying states in 85Ge. In order to inspect the sensitivity of the results to the neutron d5/2 and s1/2 single-particle states, we performed an analysis of the level structure in the N = 51 83Ge and N = 53 85Ge isotopes. [ABSTRACT FROM AUTHOR]

The β-decay properties of neutron-rich fission fragments of Cu, Zn, and Ga isotopes were studied at the Holifield Radioactive Ion Beam Facility. Beams of 75-79Cu, 79-81Zn, and 83-85Ga were formed and delivered to two new end-stations at the facility. The Low-energy Radioactive Ion Beam Spectroscopy Station is a traditional on-line low energy (200 keV) beam line with 4 clover Ge detectors, two half-cylindrical plastic β-detectors, and a moving tape collector. In addition, many of the beams were accelerated to above 2 MeV/u and delivered to a micro-channel plate and transmission ion chamber located just in front of the same detector setup. In both cases, fine adjustment of an isobar separator was used to enhance the isotope of interest. Excited levels in the daughters and β-delayed neutron branching ratios were measured and used to confirm isotope identification. The decays from 79Cu and 85Ga were observed for the first time as was the 84Ge 2+1 level populated by β and βn decay channels. [ABSTRACT FROM AUTHOR]

The properties of β-γ and β-delayed neutron emission from 76-79Cu and 83-85Ga were measured at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. Selected results on the decay properties of copper isotopes are briefly presented and discussed. [ABSTRACT FROM AUTHOR]