Measurements of the ¹³⁴Xe Neutron Capture Cross-section Between 0.43 and 5.5 MeV

In the study of rare event physics, such as neutrinoless double beta decay, it is important to understand potential background events. Events such as cosmic rays and stray alpha particles can lead to neutron-induced events even in experiments deep underground. Experiments that study neutrinoless double beta decay of ¹³⁶Xe use material enriched in ¹³⁶Xe. However, a substantial fraction of the enriched material is ¹³⁴Xe. One neutron-induced event of interest is neutron capture on ¹³⁴Xe, which can emit gamma rays that have the potential to Compton scatter into the Q-value region of interest for double-beta decay of ¹³⁶Xe. In this study, we investigate neutron capture on ¹³⁴Xe by looking for gamma rays emitted from both the de-excitation of resultant metastable excited states of ¹³⁵Xe, and the subsequent decay to ¹³⁵Cs. Highly enriched xenon gas was irradiated in the neutron beam at Triangle Universities Nuclear Laboratory, and the resultant decays were counted in the low-background counting facility located in the Duke Physics Building. We will report our results for the neutron capture cross-section for incident neutron energies of 0.43, 0.8, 1.5, 2.0, 4.2, and 5.5 MeV.