Determination of the E1 component of the low-energy C-12(alpha,gamma)O-16 cross section

A measurement of the beta-delayed alpha decay of N-16 using a set of twin ionization chambers is described. Sources were made by implantation, using a N-16 beam produced via the In-Flight Technique. The energies and emission angles of the C-12 and alpha particles were measured in coincidence and very clean alpha spectra, down to energies of 450 keV, were obtained. The structure of the spectra from this experiment is in good agreement with results from previous measurements. An analysis of our data with the same input parameters as used in earlier studies gives S-E1(300) = 86 +/- 22 keVb for the E1 component of the S-factor. This value is in excellent agreement with results obtained from various direct and indirect measurements. In addition, the influence of new measurements including the phase shift data from Tischhauser et al. on the value of S-E1(300) is discussed.