Speaker
Description
The TESSERACT experiment is a collection of detectors searching for sub-GeV particle dark matter using sensitive transition-edge sensors. The complementary target materials include superfluid helium-4, polar crystals, and semiconductor crystals, each focusing on various low mass dark matter models. Superfluid helium-4 is an interesting target because of its light atomic mass, three signal channels, and more. Using a dilution refrigerator, SQUIDs, and multiple sensors with resolution down to ~400 meV, we collect both atomic signals and quasiparticle excitations, allowing study of helium behavior and low energy excess. I will present recent R&D progress, detector modeling, and calibrations of the helium target as we look towards moving underground at Modane Underground Laboratory in 2028.