Cross sections and thermonuclear reaction rates for the 28Si(α, p)31P and 54Fe(α, p)57Co reactions

Abstract

Absolute cross sections for the 28Si(α, p)31P and 54Fe(α, p)57Co reactions have been measured for laboratory bombarding energies over the range 5.52 ≤ Eα ≤ 12.00 MeV, using targets of approximately 4-keV thickness. Ground state reaction rates were then deduced from these cross sections and stellar rates were deduced by multiplying by the ratio of stellar-to-ground state rates obtained from statistical model calculations. Stellar rates for the reverse reactions have been determined and are fitted by a parametric equation for ease of interpolation. The experimental cross sections and rates have been compared with statistical model calculations and are in reasonable agreement for the 54Fe(α, p)57Co reaction but deviate by as much as a factor of three for the 28Si(α, p)31P reaction.