Quick Shot

The nuclear science community has an increased interest in the structure of light nuclei and their interactions at energies approaching 1 MeV. Many of these reactions have been previously measured in this energy range using accelerators; however, experimental results disagree and have large uncertainties. In addition, several of these product half-lives are too short (100 ms to 10 s) for removing samples and conducting activation measurements. Therefore, a technique using target normal sheath acceleration (TNSA) was developed on the Multi-Terawatt (MTW) laser to measure light-ion reactions at MeV energies that allows access to these short-lived half-lives. In July 2023, a successful measurement from a joint MTW experimental campaign between SUNY Geneseo, Houghton University, and LLE took place using the Houghton–Geneseo short-lived isotope counting system and the Geneseo particle time-of-flight detector. This Phoswich detector is designed to detect low-intensity, low-energy beta particles efficiently in a higher-energy ambient background. For this design, there is a combination of scintillators with dissimilar pulse shape characteristics optically coupled to each other and to a common photomultiplier tube(s). Pulse-shape analysis distinguishes the signals from the two scintillators, identifying in which scintillator the event occurred. The reaction was used to show that the proof-of-principle was ⁷Li(d,p)⁸Li, for which the ⁸Li product has a half-life of 840 ms that was measured to well within the accepted uncertainty from past measurements. The next goal is to use this detector on OMEGA to diagnose the ⁷Li(t,α)⁶He* reaction.