Lifetime measurement of the 6.79 MeV state in {sup 15}O with the AGATA demonstrator

Journal Article · Tue Nov 20 00:00:00 EST 2012 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4768511· OSTI ID:22075819

Depalo, R; Michelagnoli, C; Menegazzo, R; Ur, C A; Bazzacco, D; Bemmerer, D; Broggini, C; Caciolli, A; Erhard, M; Farnea, E; Fueloep, Zs; Gottardo, A; Keeley, N; Lunardi, S; Marta, M; Mengoni, D; Mijatovic, T; Recchia, F; Rossi-Alvarez, C; Szuecs, T ^[1] ; others, and

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1. INFN Sezione di Padova, Padova (Italy) and Dipartimento di Fisica dell'Universita di Padova, Padova (Italy)

The {sup 14}N(p,{gamma}){sup 15}O reaction is the slowest process of the CN cycle, and thus it is of high astrophysical interest since it regulates the total rate of energy and neutrinos production through the cycle. The {sup 14}N+p ground state capture is strongly influenced by a sub-threshold resonance corresponding to the 6.79 MeV state in {sup 15}O. The width of this resonance is a major source of uncertainty in the extrapolation of the reaction cross section in the Gamow energy window. Preliminary results of a new Doppler Shift Attenuation measurement of the lifetime of the 6.79 MeV state in {sup 15}O are discussed. The level of interest was populated via the {sup 2}H({sup 14}N,n){sup 15}O reaction in inverse kinematics at 32 MeV beam energy. The gamma-rays emitted in the decay of the 6.79 MeV level to the ground state were detected with the AGATA Demonstrator array of high-purity germanium detectors. The sensitivity of the shape of the peak in the gamma-ray energy spectrum to the level lifetime is investigated comparing the experimental peaks with detailed Monte Carlo simulations of the reaction mechanisms and the gamma-ray emission and detection. Nuclear levels in {sup 15}N (also populated in the {sup 14}N+{sup 2}H reaction) for which the lifetimes are known in the literature provided a test of the analysis technique.

• OSTI ID: 22075819
• Journal Information: AIP Conference Proceedings, Vol. 1498, Issue 1; Conference: Carpathian summer school of physics 2012, Sinaia (Romania), 24 Jun - 7 Jul 2012; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASTROPHYSICS
CAPTURE
COMPUTERIZED SIMULATION
CROSS SECTIONS
DSA METHOD
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
GAMMA RADIATION
GAMMA SPECTROSCOPY
GE SEMICONDUCTOR DETECTORS
GROUND STATES
LIFETIME
MEV RANGE
MONTE CARLO METHOD
NITROGEN 14
NITROGEN 15
OXYGEN 15
PROTON REACTIONS
PROTON-NUCLEON INTERACTIONS