GAMMA-WIDTH OF O-14-ASTERISK(5.17 MEV) AND THE STELLAR N-13(P, GAMMA)O-14 REACTION-RATE

We have determined the gamma-ray branching ratio GAMMA(gamma)/GAMMA(to t) for the first excited state in O-14 (E(x) = 5.17 MeV) to be (3.1 +/ - 1.7) X 10(-4), corresponding to a gamma width of 12 +/- 7 eV. This v alue was determined by measuring the ratio of the N-14(p, n)O-14(0) to N-14(p, n)O-14(1) cross sections via neutron time of flight, and the ratio of N-14(p, n)O-14(0) to N-14(p, n)O-14(1)(gamma)O-14(0) cross se ctions at the same center-of-mass energy by bombarding a hydrogen targ et with a N-14 beam and kinematically distinguishing the O-14(0) recoi ls from the two reaction channels. The present value for GAMMA(gamma) is consistent with other measurements at the 2-sigma level; a weighted mean of all measurements is used to calculate the stellar N-13(p, gam ma)O-14 reaction rate, and thereby determine the temperatures and dens ities at which the stellar carbon-nitrogen-oxygen (CNO) cycle is conve rted to the hot CNO cycle.