Speaker
Description
In collaboration between the Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches (COSINUS)—a dual-channel dark-matter direct-detection experiment employing sodium iodide (NaI) as target material—and the Observatory for Neutrino and Dark Matter Electron Scattering (OνDES) project, we developed a cryogenic scintillating calorimeter that enables photon-number-resolved measurements of scintillation light from NaI. The detector module comprises a NaI crystal with a remote Transition Edge Sensor (remoTES) for phonon readout, complemented by multiple silicon light absorbers instrumented with Transition Edge Sensors (TESs) to detect the scintillation signal. The improved light resolution is achieved by using several small silicon absorbers rather than a single large light detector; the reduced heat capacity enhances sensitivity and enables lower detection thresholds. This capability allows a precise characterization of the scintillation light yield of ultrapure NaI crystals, an essential input for the analysis of forthcoming COSINUS data. Moreover, the demonstrated technology provides the basis for future studies of dark matter-electron interactions within OνDES. This contribution presents the detector design and results from a prototype measurement.
| Main Contribution topic | Direct detection |
|---|---|
| Secondary contribution topic | Instrumentation for Dark Matter |