Dark Matter Detection with the Snowball Chamber

The Snowball Chamber is an R&D project investigating the use of supercooled water as the target medium for dark matter detectors. The water is in a metastable state, and nucleation followed by freezing can be triggered by nuclear recoils from neutrons or dark matter. Additionally, the detector will be insensitive to electron and gamma backgrounds. Freezing is an exothermic reaction, making it entropically favorable. The detector has an expected sensitivity to low-mass dark matter in the sub-GeV energy range. We have assembled a detector prototype consisting of a quartz vessel with 3 calibrated temperature sensors (RTDs), cooled in an ethanol bath using a cryocooler, and a borescope camera, which captures when freezing occurs. An electrical panel was built to power the sensors and readout modules, and a custom LabVIEW code was created to read and log the data. Background data has been taken by cooling down the chamber to -10ºC and then waiting for spontaneous freezing, and the analysis results will be presented in the poster. In the future, data using neutron and gamma sources will be taken and compared to the background data.