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Title: Measurement of the {sup 13}C(α,n){sup 16}O reaction with the Trojan horse method: Focus on the sub threshold resonance at −3 keV

The {sup 13}C(α,n){sup 16}O reaction is the neutron source of the main component of the s-process. The astrophysical S(E)-factor is dominated by the −3 keV sub-threshold resonance due to the 6.356 MeV level in {sup 17}O. Its contribution is still controversial as extrapolations, e.g., through R-matrix calculations, and indirect techniques, such as the asymptotic normalization coefficient (ANC), yield inconsistent results. Therefore, we have applied the Trojan Horse Method (THM) to the {sup 13}C({sup 6}Li,n{sup 16}O)d reaction to measure its contribution. For the first time, the ANC for the 6.356 MeV level has been deduced through the THM, allowing to attain an unprecedented accuracy. Though a larger ANC for the 6.356 MeV level is measured, our experimental S(E) factor agrees with the most recent extrapolation in the literature in the 140-230 keV energy interval, the accuracy being greatly enhanced thanks to this innovative approach, merging together two well establish indirect techniques, namely, the THM and the ANC.
Authors:
 [1] ; ; ; ; ;  [2] ;  [3] ;  [4] ; ; ; ; ;  [5] ;  [6] ;  [7]
  1. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Catania (Italy)
  2. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Catania and Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)
  3. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Catania and Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, and Dipartimento di Fisica, Università di Perugia, Perugia (Italy)
  4. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Catania and Institute of Nuclear Research (ATOMKI), Debrecen (Hungary)
  5. Department of Physics, Florida State University, Tallahassee, Florida (United States)
  6. Cyclotron Institute, Texas A and M University, College Station, Texas (United States)
  7. Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)
Publication Date:
OSTI Identifier:
22280460
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1594; Journal Issue: 1; Conference: OMEG12: 12. international symposium on origin of matter and evolution of galaxies, Tsukuba (Japan), 18-21 Nov 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; ALPHA REACTIONS; ASTROPHYSICS; ASYMPTOTIC SOLUTIONS; CALCULATION METHODS; CARBON 13 TARGET; COMPUTERIZED SIMULATION; COSMOLOGY; EXTRAPOLATION; KEV RANGE; LITHIUM 6 REACTIONS; MEV RANGE; NEUTRONS; NUCLEAR REACTION YIELD; OXYGEN 16; OXYGEN 17; R MATRIX; S PROCESS; SPECTROSCOPIC FACTORS