O17andO19Lifetimes by a Particle-Gamma Coincidence Technique

Lifetimes of the 96-keV and 1.47-MeV levels in ${\mathrm{O}}^{19}$ produced by the ${\mathrm{O}}^{18}(d, p){\mathrm{O}}^{19}$ reaction have been measured from the distribution of time delays between protons and the appropriate decaying gamma rays. A solid-state detector was used both as a timing and as an energy-measuring device for the protons. The time-delay distributions were obtained with a time-to-height converter in the normal fast-slow coincidence arrangement. The measured half-lives of the 96-keV and 1.47-MeV levels in ${\mathrm{O}}^{19}$ are 1.39±0.05 nsec and ≤75 psec, respectively. These results are compared with intermediate-coupling shell-model calculations. Using this particle-gamma coincidence technique a remeasurement of the lifetime for the 871-keV level in ${\mathrm{O}}^{17}$ produced by the ${\mathrm{O}}^{16}(d, p){\mathrm{O}}^{17}$ reaction resulted in a half-life of 182±5 psec.