First Spectral Measurement Of Deuterium-Tritium Fusion Gamma Rays In Inertial Fusion Experiments

The R-matrix analysis of A = 5 nuclear systems has been partially validated by applying the technique to the Li-5 system and comparing the predicted gamma-ray spectrum with historical data. R-matrix analysis of the similar He-5 system was then used to predict the gamma-ray spectral shape for the deuterium-tritium (DT) reaction. The resulting spectra have been used in the analysis of DT implosions on the Omega laser where the gamma-ray interaction rate was measured by a gas Cherenkov detector. Comparison of predictions to experiment confirmed the presence of both 16.75 and approximate to 13 MeV gamma-ray contributions; analysis, using R-matrix spectra, yielded a ratio of gamma-ray emission from a transition to the intermediate excited state to that from a transition to the ground state of (2.1 +/- 0.4) : 1, substantiating the first spectral measurement of the DT fusion gamma ray in an inertial fusion environment.