A new determination of the astrophysical S-factor S{sub E1} of the {sup 12}C({alpha},{gamma}){sup 16}O reaction

A new measurement of the {beta}-delayed {alpha} decay of {sup 16}N has been performed using a set of high efficiency ionization chambers. Sources were made by implantation of a {sup 16} beam, yielding very clean {alpha} spectra down to energies as low as 400 keV. Our data are in good agreement with earlier results. For the S factor SE1, we obtain a value of 74{+-}21 keV b. In spite of improvements in the measurement, the error in SE1 remains relatively large because of the correlations among the fit parameters and the uncertainties inherent to the extrapolation.