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Ciemny, A. A.

Publications and source records attributed to Ciemny, A. A..

7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

β -delayed charged-particle decay of Si 22 , 23

The β decay of 22,23 Si by emission of delayed charged particles was investigated in an experiment at the Cyclotron Institute of Texas A&M University by means of an optical-readout time-projection chamber. The previously-known decay of the two isotopes by β-delayed one- and two-proton emission was confirmed. Here for the first time, a new, rare, decay mode for 23 Si, β-delayed three-proton emission, was observed and β-delayed proton-α emission tentatively identified. Moreover, the β-decay pattern for the ground state of 23 Si was studied by means of multireference density-functional-rooted calculations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Production of the most neutron-deficient Zn isotopes by projectile fragmentation of Kr 78

The cross sections for the production of three most neutron-deficient zinc isotopes, 54–56 Zn, in the projectile fragmentation of 78 Kr at 345 MeV/nucleon on a beryllium target, were measured. Although the results are smaller by over an order of magnitude from those obtained with a 58 Ni beam at 75 MeV/nucleon on a nickel target, the rates of reaction products are found to be larger in the case of high-energy fragmentation of 78 Kr. The experimental cross sections for the most neutron-deficient isotopes of even-Z nuclei between zinc and krypton were analyzed in the framework of the abrasion-ablation model. A very good agreement with the data was found when the nuclear masses predicted by a particular variant of the Hartree-Fock-Bogoliubov mass model were used. The prospects for the observation of more exotic isotopes in this region are discussed in context of 2p radioactivity.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Mapping of fragmented νf 5/2 →πf 7/2 transitions in the 73 Co→ 73 Ni decay

Excited states in 73 , 75 Ni were investigated through the β decay of 73 , 75 Co in an experiment performed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). The experimental results extended the level scheme of Ni 73 to 3.2-MeV excitation energy and provided the experimental information on excited states in Ni 75 . The β -delayed neutron branching ratio for Co 73 was obtained. Furthermore, the experimental results are discussed in comparison with shell-model calculations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

Updated β -decay measurement of neutron-rich Cu 74

Here, the β decay of neutron-rich 74 Cu has been studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. By using a high-resolution mass separator a purified 74 Cu beam was obtained, thus allowing decay through its isobar chain to stable 74 Ge without any decay chain member dominating. A total of 170γ rays were associated with 74 Cuβ decay with 111 placed in the 74 Zn level scheme. Updated β feeding intensities and estimated log(ft) values are presented, and new J π assignments are proposed using shell model calculations. The progression of simulated total absorption γ-ray spectroscopy (TAGS) based on proposed levels and β-feeding values from previous measurements to this evaluation are presented and demonstrate the need for a TAGS measurements for this and similar decays.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

β and β – n decay of the neutron-rich Ge 84 nucleus

In this study, the β-decay properties of the very neutron-rich 84 Ge nucleus were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. Several new γ-transitions and levels were added to its decay scheme and the order of the two lowest-lying levels in the daughter 84 As was corrected. For the first time γ radiation following β-delayed neutron emission was observed. The shell-model calculations and apparent β transition intensities were used to guide the spin assignment to the 84 As levels, in particular for the low-energy part of the level scheme. The new spin-parity (2 – ) proposed for the ground state of 84 As is supported also by the systematics of N = 51 isotones.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Experimental study of β and β - n decay of the neutron-rich N = 54 isotone As 87

The β-decay properties of neutron-rich 87 As produced in the proton-induced fission of 238 U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The low-energy excited states in N = 53 87 Se and N = 52 86 Se were identified through β - γ and β-delayed neutron-γ decay of 87 As , respectively. In conclusion, the experimental systematics of low-energy levels of N = 53 isotones, Z = 34 87 Se, and Z = 32 85 Ge, and along with an analysis of shell-model calculations, allow us to discuss the main features of excited states expected for the next N = 53 isotone, 83 Zn .

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗