Investigation of structure in {sup 23}Al via resonant proton scattering of {sup 22}Mg+p and the {sup 22}Mg(p,{gamma}) {sup 23}Al astrophysical reaction rate

Journal Article · Thu Nov 15 04:00:00 EST 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.055802· OSTI ID:21067933

He, J J; Kubono, S; Teranishi, T; Notani, M ^[1]; Baba, H ^[1]; Nishimura, S; Nishimura, M; Yanagisawa, Y ^[2]; Moon, J Y; Lee, J H; Lee, C S ^[3]; Iwasaki, H ^[1]; Hokoiwa, N; Kibe, M; Gono, Y ^[4]; Kato, S ^[5]

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1. Center for Nuclear Study (CNS), University of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
2. RIKEN -Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
3. Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)
4. Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan)
5. Department of Physics, Yamagata University, Yamagata 990-8560 (Japan)

Proton resonant states in {sup 23}Al have been investigated for the first time by the resonant elastic and inelastic scattering of {sup 22}Mg+p with a {sup 22}Mg beam at 4.38 MeV/nucleon bombarding a thick (CH{sub 2}){sub n} target. The low-energy {sup 22}Mg beam was separated by the CNS radioactive ion beam separator (CRIB). The energy spectra of recoiled protons were measured at average scattering angles of {theta}{sub lab}{approx_equal} 4 deg., 17 deg. and 23 deg. A new state has been observed at E{sub x}=3.00 MeV with a spin-parity assignment of (3/2{sup +}). In addition, resonant inelastic scattering has populated three more states at excitation energies of 3.14, 3.26, and 3.95 MeV, with proton decay to the first excited state in {sup 22}Mg being observed. The new state at 3.95 MeV has been assigned a spin-parity of J{sup {pi}}=(7/2{sup +}). The resonant parameters were determined by an R-matrix analysis of the excitation functions with a SAMMY-M6-BETA code. The core-excited structure of {sup 23}Al is discussed within a shell-model picture. The stellar reaction rate of the {sup 22}Mg(p,{gamma}){sup 23}Al reaction has been reevaluated, and the revised total reaction rate is about 40% greater than the previous result for temperatures beyond T{sub 9}=0.3.

• OSTI ID: 21067933
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 76; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM 23
ASTROPHYSICS
ENERGY SPECTRA
EXCITATION
EXCITATION FUNCTIONS
EXCITED STATES
HEAVY ION REACTIONS
INELASTIC SCATTERING
MAGNESIUM 22
MEV RANGE
NUCLEAR REACTION KINETICS
NUCLEAR STRUCTURE
PARITY
PROTON REACTIONS
PROTON-EMISSION DECAY
PROTONS
R MATRIX
RADIOACTIVE ION BEAMS
SHELL MODELS
SPIN