Speaker
Description
The ALPS II light-shining-through-walls experiment at DESY in Hamburg plans to use Transition Edge Sensors (TESs) to detect low-energy single-photons originating from axion(ALP)-photon conversion with rates as low as $10^{-5}~$s$^{-1}$. Even beyond ALPS II, these superconducting microcalorimeters, operated at cryogenic temperatures, could help search for further particle-DM candidates. Much of the work to ensure the viability of the TES detector for use in ALPS II, such as calibrating the detector and mitigating external sources of backgrounds, also leads to the ability to utilize the TES for an independent direct-DM search. For this purpose, the superconducting sensor, sensitive to sub-eV energy depositions, can be used as a simultaneous target and sensor for DM-electron scattering for sub-MeV DM. Hence, direct DM searches with TES could explore parameter space as of yet inaccessible by nucleon-scattering experiments. The first calibration of the TES for sub-eV energies demonstrates promising results in the pursuit of this goal, alongside the dedicated background measurements and ensuing analysis.
