Screening materials with the XIA UltraLo alpha particle counter at Southern Methodist University

Abstract

Southern Methodist University houses one of five existing commercially available UltraLo 1800 production model alpha counters made by XIA LLC. The instrument has an electron drift chamber with a 707 cm 2 or 1800 cm 2 counting region which is determined by selecting the inner electrode size. The SMU team operating this device is part of the SuperCDMS screening working group, and uses the alpha counter to study the background rates from the decay of radon in materials used to construct the SuperCDMS experiment. We have studied four acrylic samples obtained from the MiniCLEAN direct dark matter search with the XIA instrument demonstrating its utility in low background experiments by investigating the plate-out of 210 Pb and comparing the effectiveness of cleaning procedures in removing 222 Rn progenies from the samples.

Radioassay facilities at the STFC Boulby Underground Laboratory

“…A comparison between signals from these two readout planes can be used to veto any signals not originating from the sample. The UltraLo-1800 has been used in a number of assay programmes [17][18][19].…”