E1 and E2 cross sections of the {sup 12}C({alpha},{gamma}{sub 0}){sup 16}O reaction using pulsed {alpha} beams

Journal Article · Tue Dec 15 00:00:00 EST 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.80.065802· OSTI ID:21296634

Makii, H; Nagai, Y; Shima, T; Segawa, M; Mishima, K; Ueda, H ^[1]; Igashira, M; Ohsaki, T ^[2]

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1. Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)
2. Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 (Japan)

We measured the {gamma}-ray angular distribution from {sup 12}C({alpha},{gamma}{sub 0}){sup 16}O to the ground state of {sup 16}O using a pulsed {alpha} beam at E{sub eff}=1.6 and 1.4 MeV. True events of {sup 12}C({alpha},{gamma}{sub 0}){sup 16}O were discriminated from background events with a time-of-flight method because of neutrons from {sup 13}C({alpha},n){sup 16}O. The obtained {gamma}-ray spectrum with anti-Compton NaI(Tl) spectrometers showed a characteristic line shape from {sup 12}C({alpha},{gamma}{sub 0}){sup 16}O: the Doppler broadening and energy loss of {alpha} particles in {sup 12}C targets. A Rutherford backscattering spectrum of {alpha} particles from enriched {sup 12}C targets was measured during beam irradiation to obtain the target thickness and incident {alpha}-beam intensities. The astrophysical S factors for E1 and E2,S{sub E1}({gamma}{sub 0}:E{sub eff}) and S{sub E2}({gamma}{sub 0}:E{sub eff}), derived from the present cross sections are in excellent agreement with the values derived by R-matrix calculation of the {beta}-delayed {alpha} spectrum of {sup 16}N, and by using the asymptotic normalization constant in the R-matrix fit.

• OSTI ID: 21296634
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 80, Issue 6; Other Information: DOI: 10.1103/PhysRevC.80.065802; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
ALPHA REACTIONS
ALPHA SPECTRA
ANGULAR DISTRIBUTION
ASYMPTOTIC SOLUTIONS
BEAMS
CARBON 12 TARGET
CARBON 13
CROSS SECTIONS
DOPPLER BROADENING
E1-TRANSITIONS
E2-TRANSITIONS
ENERGY LOSSES
GAMMA DECAY
GAMMA RADIATION
GAMMA SPECTRA
GROUND STATES
MEV RANGE 01-10
NEUTRONS
NITROGEN 16
OXYGEN 16
R MATRIX
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SODIUM IODIDES
SPECTROMETERS
TIME-OF-FLIGHT METHOD