Study of the beta-delayed alpha-particle emission of 16N.

The beta-delayed alpha-particle emission of [sup 16]N has been studied, with [sup 16]N nuclei produced using 80 MeV/nucleon [sup 18]O beams on [sup 9]Be targets. The [sup 16]N secondary nuclei were mass analyzed and separated from the reaction products using the Michigan State University A1200 isotope separator. A detector array, including four thin surface barrier detectors, a [ital p]-[ital i]-[ital n] diode, a Ge gamma-ray detector, and a two-dimensional position sensitive parallel plate avalanche counter, was used for implantation and study of the separated nuclei. A beta-decay branching ratio of (1.3[plus minus]0.3)[times]10[sup [minus]5] to the 1[sup [minus]] state at 9.6 MeV and a centroid of 2.35[plus minus]0.05 MeV for the beta-delayed alpha-particle emission were measured. These results are essential for the analysis of a high sensitivity measurement at Yale University of the low-energy beta-delayed alpha-particle emission of [sup 16]N, and for understanding the [sup 12]C([alpha],[gamma])[sup 16]O reaction in the helium burning process in massive stars.