Speaker
Description
Transition-edge sensors (TESs) are highly sensitive detectors capable of measuring extremely small energy depositions with excellent energy resolution in the sub-eV to eV range. However, the target material of the COSINUS experiment, sodium iodide (NaI), is incompatible with standard TES fabrication processes. To overcome this limitation, the COSINUS collaboration has developed the remoTES design. In this configuration, the TES is fabricated on a separate wafer and thermally coupled to the absorber via a gold link. This physical separation between absorber and sensor offers several advantages, including compatibility with a wider range of materials that could not previously be employed as cryogenic calorimeters. Furthermore, this approach enables scalable and reproducible TES fabrication on a dedicated wafer material, facilitating the mass production required for next-generation large-scale rare-event searches. In this contribution, we present recent R&D results demonstrating that the remoTES design achieves an energy resolution comparable to conventional TES detectors, reaching the eV scale. This performance opens the possibility to probe the low-energy excess using the remoTES design.
