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Title: Measurement of key resonances for the Al 24 ( p , γ ) Si 25 reaction rate using in-beam γ -ray spectroscopy

Energy levels and branching ratios for the rp-process nucleus 25Si were determined from the reactions 9Be ( 26Si, 25Si) X and 9Be ( 25Al, 25Si) X using in-beam γ-ray spectroscopy with both high-efficiency and high-resolution detector arrays. Proton-unbound states at 3695(14) and 3802(11) keV were identified and assigned tentative spins and parities based on comparison to theory and the mirror nucleus. The 24Al (p, γ) 25Si reaction rate was calculated using the experimental states and states from charge-dependent USDA and USDB shell-model calculations with downward shifts of the 1s 1/2 proton orbital to account for the observed Thomas-Ehrman shift, leading to a factor of 10–100 increase in rate for the temperature region of 0.22 GK as compared to a previous calculation. These shifts may be applicable to neighboring nuclei, impacting the proton capture rates in this region of the chart.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [6] ;  [1] ;  [1] ;  [4] ;  [7]
  1. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy
  2. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Michigan State Univ., East Lansing, MI (United States). JINA Center for the Evolution of the Elements
  3. iThemba LABS, Cape Town (South Africa); Univ. of Stellenbosch, Stellenbosch (South Africa). Dept. of Physics
  4. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab
  5. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab; Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics
  6. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab; TRIUMF, Vancouver, BC (Canada)
  7. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab; Science and Technology Facilities Council (STFC), Harwell Campus, Oxford (United Kingdom). Diamond Light Source, Ltd.
Publication Date:
Grant/Contract Number:
FG02-08ER41556; NA0003180; PHY-1102511; PHY-1565546; PHY-1404442; 105608
Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 97; Journal Issue: 5; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Research Org:
Michigan State Univ., East Lansing, MI (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA) Nuclear Science and Security Consortium (NSSC); USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF); National Research Foundation (NRF) (South Africa)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
OSTI Identifier:
1435972
Alternate Identifier(s):
OSTI ID: 1436008; OSTI ID: 1458531