July 29, 2019 to August 2, 2019
Northeastern University
US/Eastern timezone

Estimating Si-32 and tritium in the SuperCDMS SNOLAB detectors

Jul 30, 2019, 5:25 PM
West Village G 102 (Northeastern University)

West Village G 102

Northeastern University

Oral Presentation Dark Matter Dark Matter


John Orrell (Pacific Northwest National Laboratory)


The SuperCDMS SNOLAB experiment will search for low-mass (< 10 GeV/c^2) dark matter employing germanium and silicon crystals instrumented with cryogenic phonon and ionization detectors. The expected dominant backgrounds are due to long-lived radioactive isotopes present and/or produced in the natural environment. Specifically, Si-32 is cosmogenically created in the atmosphere and is incorporated into silicon ‘ore’ through natural precipitation (rain) processes. This pure beta-decay background from Si-32 (and progeny P-32) is only significant in silicon-based detectors. However, both germanium and silicon crystals accumulate tritium – another pure beta emitter – due to nuclear spallation as a result of exposure to cosmic-ray secondaries. This presentation will overview the SuperCDMS SNOLAB experiment and review calculation assumptions and background rate expectations for Si-32 and tritium levels which are expected to be the primary backgrounds for the experiment.

Primary author

John Orrell (Pacific Northwest National Laboratory)


SuperCDMS Collaboration

Presentation materials