DD neutron generator calibration in LUX-ZEPLIN dark matter search experiment

Nuclear recoil (NR) calibration is critical to understanding the response of a detector searching for dark matter candidates through direct interaction with normal matter. The LUX-ZEPLIN (LZ) Experiment is one such direct detection experiment. Monoenergetic 2.45 MeV neutrons from Adelphi Technologies’ DD 109 neutron generator were used for absolute NR calibration. DD neutrons can also serve as a unique low monoenergetic source by reflecting generated neutrons off a deuterium- or hydrogen-loaded target, reducing the neutron energy to 350 keV, or to 10-100 keV, respectively. Here, scintillation light from the reflector allows for a direct measurement of the energy using the time of flight of tagged neutrons between the reflector and the target. DD neutrons can provide an in-situ measurement of LZ’s NR band, an independent light and charge yield calibration, and an understanding of other various aspects of detector behavior. In this talk, I will discuss NR calibration using both direct and reflected DD neutrons in addition to its physical implementation.