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
- Center for Nuclear Study (CNS), University of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
- RIKEN -Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
- Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)
- Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan)
- 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, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevC.76.055802; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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