Speaker
Description
Transition Edge Sensors (TES) are superconducting microcalorimeters that can be used for
single-photon detection at extremely low backgrounds. When they are within their supercon-
ducting transition region ($\sim140~$mK for the TES in this work) small temperature fluctuations
- like the energy deposited by single photons - lead to large variations in resistance. These
variations can be measured using Superconducting Quantum Interference Devices (SQUIDs).
This exciting technology will be used as a single-photon detector for the upcoming ALPS II
experiment, a light-shining-through-walls experiment at DESY Hamburg, searching for Axion-
Like Particles (ALPs), which are possible Dark Matter (DM) candidates. At ALPS II, the
detector needs to detect single photons with a wavelength of $1064~$nm at a rate of $\sim10^{-5}~$Hz
leading to very stringent dark count requirements. Therefore, the main challenges in com-
missioning a TES for ALPS II involve determining and increasing its detection efficiency and
reducing dark counts as well as backgrounds introduced by e.g. black-body radiation. Due to
the very low dark count rates in our setup, our TES system might be viable for direct DM
searches at sub-MeV masses using electron-scattering of DM in the superconducting material,
as well.
In this work, the commissioning of a TES for the ALPS II experiment will be outlined, followed
by an outlook on the possible application of TESs as detectors for direct DM searches.
Category | Particle / Astroparticle / Cosmology (Experiment) |
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