Laser-driven tritium beams to study nuclear reactions between light nuclei*

A controllable tritium beam makes accessible rarely studied di-neutron transfer reactions with light nuclei. These reactions are of high interest to fundamental nuclear physics for several reasons, including the generation of exotic, neutron-rich isotopes like ⁹Li or ¹¹Be, and the potential correlation of neutrons during transfer. After several decades, accelerator facilities become increasingly willing to tackle the challenges associated with tritium handling again to address these scientific questions. Laser-accelerated triton beams can fill in an important gap in the low energy (<3 MeV) regime that is of high interest to nuclear astrophysics and currently not covered by accelerators. In addition, laser-accelerated tritons are delivered within nanoseconds, enabling more statistically significant activation experiments compared to accelerators. Currently, an OMEGA/OMEGA-EP platform exists that produces approximately 10¹³ tritons with an energy spectrum peaked at 1.5 MeV and an appreciable tail to about 4.5 MeV, which has been successfully used in nuclear reaction benchmarking experiments.

 

Experiments with this beam are proposed on the new NSF-OPAL facility that is currently being designed, taking advantage of a higher rep-rate of 5 mins per shot vs 90 mins per shot. These experiments are expected to deliver much improved statistics compared to the existing data, enabling an effective deconvolution of the measured cross section from the triton energy spectrum to study reactions like ⁷Li(t, p)⁹Li and ⁹Be(t, p)¹¹Be. Data from previous experiments and will be discussed in the context of the NSF-OPAL platform.