High-precision Si-28(p,t)Si-26 reaction to determine Mg-22(alpha, p)Al-25 reaction rates

作者：Matic A^*; van den Berg A M; Harakeh M N; Wortche H J; Beard M; Berg G P A; Goerres J; LeBlanc P; O'Brien S; Wiescher M; Fujita K; Hatanaka K; Sakemi Y; Shimizu Y; Tameshige Y; Tamii A; Yosoi M; Adachi T; Fujita Y; Shimbara Y; Fujita H; Wakasa T; Greene J P; Crowter R; Schatz H

来源：Physical Review C, 2011, 84(2): 025801.

DOI：10.1103/PhysRevC.84.025801

The rise time of stellar x-ray bursts is a signature of thermonuclear runaway processes in the atmosphere of neutron stars and is highly sensitive to a series of (alpha, p) reactions via high-lying resonances in sd-shell nuclei. Lacking data for the relevant resonance levels, the stellar reaction rates have been calculated using statistical, Hauser-Feshbach models, assuming a high-level density. This assumption may not be correct in view of the selectivity of the (alpha, p) reaction to natural parity states. We measured the Si-28(p,t)Si-26 reaction with a high-resolution spectrometer to identify resonance levels in Si-26 above the alpha-emission threshold at 9.164 MeV excitation energy. These resonance levels are used to calculate the stellar reaction rate of the Mg-22(alpha,p)Al-25 reaction and to test the validity of the statistical assumption.

• 出版日期2011-8-24