Total Absorption Spectroscopy of Ground and Isomeric States in 70Cu
ORAL
Abstract
Theoretical models studying the origin of elements in the universe and stellar nucleosynthesis processes such the rapid neutron capture process (r-process), require physics information about beta-decay properties and neutron-capture reaction rates [1]. Currently quasiparticle random phase approximation (QRPA) calculations are used across the nuclear landscape to predict β-decay properties in astrophysical simulations [2]. QRPA calculations are typically bench-marked against known half-lives and β-delayed neutron emission probabilities, instead of comparing against the full distribution of β-decay feeding intensities (Iβ) as a function of excitation energy. Nuclei with larger β-decay Q-values have decay schemes with many weak de-excitation pathways to the ground state and β-decay branches, which are difficult to measure without high efficiency detectors. Here, we use the method of total absorption spectroscopy to investigate the β-decay of 70Cu which has three β-decaying spin-parity states (6− ground state, and two isomeric states: 3−, and 1+) and is thought to be produced in the weak r-process [3, 4]. In an experiment performed at the National Superconducting Cyclotron Laboratory 70Cu was produced, sent to the Low Energy Beam and Ion Trap (LEBIT) [5], and delivered to the Summing NaI (SuN) Total Absorption Spectrometer [6]. Spectra from the β-decay of each spin-parity state were isolated using different beam on/off periods. Iβ values from total absorption spectroscopy following the β-decay of each of the three β-decaying spin-parity states will be presented and compared to Shell Model and QRPA calculations.
[1] M. R. Mumpower, et al. Prog. in Particle and Nucl. Phys 86, (2016) 86-126.
[2] M. T. Mustonen and J. Engel. Phys. Rev. C 93 014304 (2016).
[3] P. Vingerhoets et al. Phys. Rev. C 82, 064311 (2010).
[4] R. Surman et al. AIP Advances 4, 041008 (2014).
[5] R. Ringle et al. Nucl. Inst and Meth Phys. Res. A 604 (2009) 3.
[6] A. Simon et al. Nucl. Inst and Meth. Phys. Res. A 703, (2013) 16.
[1] M. R. Mumpower, et al. Prog. in Particle and Nucl. Phys 86, (2016) 86-126.
[2] M. T. Mustonen and J. Engel. Phys. Rev. C 93 014304 (2016).
[3] P. Vingerhoets et al. Phys. Rev. C 82, 064311 (2010).
[4] R. Surman et al. AIP Advances 4, 041008 (2014).
[5] R. Ringle et al. Nucl. Inst and Meth Phys. Res. A 604 (2009) 3.
[6] A. Simon et al. Nucl. Inst and Meth. Phys. Res. A 703, (2013) 16.
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Presenters
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Eleanor K Ronning
- Michigan State University