Calibration Studies of HPGe Detectors with Differing Source Geometries — 28a — Haylee Busch, Archer Sagaskie, Zachariah Thomas, Brianna Mount Kansas Wesleyan University, Grand Valley State University, University of Michigan- Dearborn, Black Hills State University 

The LUX-ZEPLIN (LZ) experiment, located at the Sanford Underground Research Facility (SURF), aims to detect proposed interactions between ordinary matter and dark matter. In order to understand the backgrounds in LZ, it was necessary to measure the content of radionuclides in its construction materials. This is accomplished through low background counting using gamma-ray spectroscopy with High Purity Germanium (HPGe) detectors that are at Black Hills Underground Campus (BHUC) on the 4850L of SURF. The HPGe detectors were used to measure the gamma rays emitted from the LZ construction materials to determine the level of background radiation present in LZ and make adjustments to the experiment design if needed. 

Table Mountain Lattite (TML) is a loose gravel with known U,Th, and K content that is used to calibrate the BHUC’s ultra-sensitive HPGe detectors. However, it is not a perfect calibration tool as the BHUC currently uses a Marinelli beaker geometry to approximate most samples’ configuration around the HPGe crystals. 3-D printing offers an interesting avenue to explore as a 3-D model can be generated, which can then be printed as a container for TML in many different kinds of geometries. To test this, a sample of titanium slabs was selected to replicate. A series of 3D printed boxes made of PLA (Polylactic Acid) filament were printed to house TML. 

In this poster, we will compare calibration data obtained from a Marinelli beaker filled with TML with data obtained from a custom, 3-D-printed replica of the Ti plates filled with TML. Separately, a PLA filament sample was also analyzed for its U,Th,K content.

Black Hills State University
Brianna Mount