ABSTRACT
The He3(α,γ)Be7 reaction has been investigated using gaseous helium targets behind thin nickel foils and using monoenergetic alpha-particle beams with energies from 0.42 to 5.80 MeV. The prompt gamma rays were detected using NaI(Tl) scintillation spectrometers, and the resulting pulse-height spectra were analyzed to determine both the total capture cross section and the branching ratio between the cascade and the crossover transitions as functions of energy. These cross-section measurements have been used to obtain a new value for the zero-energy intercept of the cross-section factor S(E) for this reaction: S 0 = 0.47 ±0.05 keV-b, and (dS/dE)0 = −2.8×10−4 b.
