Speaker
Description
BULLKID-DM is a new experiment designed to search for low-mass WIMP-like dark matter particles (1 GeV/c or below) with nucleon cross-sections below 10 cm. The device consists of an 800 g array of over 2000 silicon dice, each acting as a particle absorber instrumented with multiplexed Kinetic Inductance Detectors (KIDs). Background rejection is achieved through a fully active structure, enabling fiducialization and anti-coincidence techniques.
A 20 g prototype, consisting of 60 voxels 5.4x5.4x5 mm in size diced from a 3'' silicon wafer, demonstrated the feasibility of this approach. Following its success, we present the first operation, in a surface laboratory equipped with a lead and copper radiation shield, of a 60 g demonstrator with 180 dice. This demonstrator setup acts as a proof of concept for the final 800 g array. The recorded backgrounds are compared to Geant4 simulations performed by the collaboration.
We also discuss ongoing R&D activities, including low-radioactivity detector mounting, a cryogenic scintillating veto readout with KIDs, in situ calibration techniques, and detector upgrades such as KIDs with dedicated phonon-collecting structures and germanium substrates for multi-target capabilities.
Finally, we outline the deployment plan of the setup at the Gran Sasso underground laboratory (LNGS). The demonstrator will be installed at LNGS by late 2026; following successful validation, the full experiment is expected to be commissioned in 2027.