Improvement of contact-less KID design using multilayered Al/Ti material for resonator

TL;DR

This paper presents advancements in contact-less KID detector technology using multilayered Al/Ti materials, achieving improved energy resolution and position independence, crucial for scalable rare event search experiments.

Contribution

The work introduces a flexible, contact-less KID detector design with multilayered Al/Ti films, demonstrating significant improvements in energy resolution and event discrimination.

Findings

Achieved keV-scale energy resolution with contact-less KID detectors.

Demonstrated ability to distinguish surface and bulk events.

Improved understanding of phonon and quasiparticle dynamics.

Abstract

The necessity to increase exposure in rare event searches experiments by maintaining a low energy threshold and a good energy resolution leads to segmented detectors as in EDELWEISS (Dark Matter), CUORE (0{\nu}\b{eta}\b{eta}) or RICOCHET (CE{\nu}NS) for example. However, the large number of sub-elements can dramatically increase the complexity of such detector arrays. In this work we report on our progress towards designing a flexible detector technology based on KID resonators evaporated on massive target crystals readout by a contact-less feed-line. Providing that we achieve O(100) eV energy threshold, such approach could easily be scaled to tens of kilogram detector arrays thanks to the intrinsic multiplexing capability of mKIDs. Using a 30 g silicon target absorber with Al/Ti multilayers for the KID resonator, we report a significant improvement of our detector response exhibiting a keV-scale energy resolution combined with the absence of position dependence on the event location. Indeed, compared to our previous work, we are now able to properly identify calibration lines from surface (20 keV X-rays) and bulk events (60 keV gamma rays). This significant improvement is an important step toward a better understanding of phonons and quasiparticles dynamics which is pivotal in optimizing this technology.