Isovector excitations in 100Nb and their decays by neutron emission studied via the Mo100(t,He3+n) reaction at 115 MeV/u
Journal Article
·
· Physics Letters. B
- Research Organization:
- University of California, Berkeley, CA (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation; USDOE Office of Science (SC), Nuclear Physics (NP); National Science Foundation (NSF); Japan Society for the Promotion of Science (JSPS)
- Grant/Contract Number:
- NA0003180; AC05-00OR22725; FG-0291-ER-40608; PHY-1102511; PHY-1430152; PHY-1068217; PHY-1404343
- OSTI ID:
- 1350785
- Alternate ID(s):
- OSTI ID: 1405175; OSTI ID: 1763502
- Journal Information:
- Physics Letters. B, Journal Name: Physics Letters. B Vol. 769 Journal Issue: C; ISSN 0370-2693
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- Netherlands
- Language:
- English
Cited by: 6 works
Citation information provided by
Web of Science
Web of Science
Similar Records
β Decay of 61V and its Role in Cooling Accreted Neutron Star Crusts
Most theoretical approaches used in nuclear astrophysics to model the nucleosynthesis of heavy elements incorporate the so-called statistical model in order to describe the excitation and decay properties of atomic nuclei. One of the basic assumptions of this model is the validity of the Brink–Axel hypothesis and the related concept of so-called photon strength functions to describe γ-ray transition probabilities. We present a novel experimental approach that allows for the first time to experimentally determine the photon strength function simultaneously in two independent ways by a unique combination of quasi-monochromatic photon beams and a newly implemented γ–γ coincidence setup. This technique does not assume a priori the validity of the Brink–Axel hypothesis and sets a benchmark in terms of the detection sensitivity for measuring decay properties of photo-excited states below the neutron separation energy. The data for the spherical off-shell nucleus 128Te were obtained for γ-ray beam-energy settings between 3 MeV and 9 MeV in steps of 130 keV for the lower beam energies and in steps of up to 280 keV for the highest beam settings. We present a quantitative analysis on the consistency of the derived photon strength function with the Brink–Axel hypothesis. The data clearly demonstrate a discrepancy of up to a factor of two between the photon strength functions extracted from the photoabsorption and photon emission process, respectively. In addition, we observe that the photon strength functions are not independent of the excitation energy, as usually assumed. Thus, we conclude, that the Brink–Axel hypothesis is not strictly fulfilled in the excitation-energy region below the neutron separation threshold (Sn = 8.78 MeV) for the studied case of 128Te.
Gamow-Teller transitions to via the reaction at and its application to stellar electron-capture rates
Journal Article
·
Mon Dec 28 00:00:00 EST 2020
· Physical Review Letters
·
OSTI ID:1350785
+20 more
Most theoretical approaches used in nuclear astrophysics to model the nucleosynthesis of heavy elements incorporate the so-called statistical model in order to describe the excitation and decay properties of atomic nuclei. One of the basic assumptions of this model is the validity of the Brink–Axel hypothesis and the related concept of so-called photon strength functions to describe γ-ray transition probabilities. We present a novel experimental approach that allows for the first time to experimentally determine the photon strength function simultaneously in two independent ways by a unique combination of quasi-monochromatic photon beams and a newly implemented γ–γ coincidence setup. This technique does not assume a priori the validity of the Brink–Axel hypothesis and sets a benchmark in terms of the detection sensitivity for measuring decay properties of photo-excited states below the neutron separation energy. The data for the spherical off-shell nucleus 128Te were obtained for γ-ray beam-energy settings between 3 MeV and 9 MeV in steps of 130 keV for the lower beam energies and in steps of up to 280 keV for the highest beam settings. We present a quantitative analysis on the consistency of the derived photon strength function with the Brink–Axel hypothesis. The data clearly demonstrate a discrepancy of up to a factor of two between the photon strength functions extracted from the photoabsorption and photon emission process, respectively. In addition, we observe that the photon strength functions are not independent of the excitation energy, as usually assumed. Thus, we conclude, that the Brink–Axel hypothesis is not strictly fulfilled in the excitation-energy region below the neutron separation threshold (Sn = 8.78 MeV) for the studied case of 128Te.
Journal Article
·
Tue Jan 01 00:00:00 EST 2019
· Physics Letters B
·
OSTI ID:1350785
+10 more
Gamow-Teller transitions to via the reaction at and its application to stellar electron-capture rates
Journal Article
·
Mon Aug 17 00:00:00 EDT 2015
· Physical Review C
·
OSTI ID:1350785
+27 more