While the BULLKID-DM collaboration is currently developing the detector array, the readout electronics, and the particle shields and the veto system, plenty of Reseach and Development efforts are currently ongoing to further improve the sensitivity of the Kinetic Inductance Detectors. These include:
Kinetic Indutance Detectors on Ge-substrates.
Germanium is a semiconductor quite like Silicon, but Ge nuclei are much heavier than Si nuclei. The elastic-scattering cross-section is depends quadratically on the neutron number N thus changing the target material from silicon (14) to germanium (41) increases the cross-section by a factor ∼ 9. More can be found here
Kinetic Indutance Detectors with Phonon collectors
In order to maximise the signal-to-noise ratio of the detectors that are meant to detect such rare and faint signals, it is important to maximise the number of phonons collected from the Silicon substrate. One possible attempt has been the development of large-area phonon collectors made of a different superconductor than the detectors so to act as a phonon-funnel. More can be found here
