A recently discovered resonance at 193 keV determines the thermonuclear rates of the ${}^{17}\mathrm{O}$ $+p$ reactions at temperatures important for the nucleosynthesis in classical novae ($T=0.1-0.4$ GK). We report on a remeasurement of this resonance in the ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ reaction by using a different kind of target compared to the previous study. Special emphasis is placed on Monte Carlo simulations of the experiment in order to better understand certain effects that have been disregarded previously. Our measured value of the resonance strength amounts to $(\omega \gamma ){}_{p\alpha }=(1.66\pm 0.17)\times {10}^{-3}$ eV, in agreement with the previously reported result. As a byproduct of our study, we find that the inhomogeneity of the foil placed in front of the α-particle detector determines the resolution in the pulse-height spectrum, and thus constrains the signal-to-noise ratio in searches of very weak ($p,\alpha$) resonances.

• Received 16 February 2007

DOI:https://doi.org/10.1103/PhysRevC.75.055808