Niobium-Based Kinetic Inductance Detectors for High-Energy Applications

Masato NARUSE  Masahiro KUWATA  Tomohiko ANDO  Yuki WAGA  Tohru TAINO  Hiroaki MYOREN  

IEICE TRANSACTIONS on Electronics   Vol.E103-C   No.5   pp.204-211
Publication Date: 2020/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.2019SEI0001
Type of Manuscript: INVITED PAPER (Special Section on Recent Progress in Superconductor Sensors and Detectors for Cutting-Edge Technologies)
Category: Superconducting Electronics
lumped element kinetic inductance detectors,  superconducting sensors,  high energy applications,  

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A lumped element kinetic inductance detector (LeKID) relying on a superconducting resonator is a promising candidate for sensing high energy particles such as neutrinos, X-rays, gamma-rays, alpha particles, and the particles found in the dark matter owing to its large-format capability and high sensitivity. To develop a high energy camera, we formulated design rules based on the experimental results from niobium (Nb)-based LeKIDs at 1 K irradiated with alpha-particles of 5.49 MeV. We defined the design rules using the electromagnetic simulations for minimizing the crosstalk. The neighboring pixels were fixed at 150 µm with a frequency separation of 250 MHz from each other to reduce the crosstalk signal as low as the amplifier-limited noise level. We examined the characteristics of the Nb-based resonators, where the signal decay time was controlled in the range of 0.5-50 µs by changing the designed quality factor of the detectors. The amplifier noise was observed to restrict the performance of our device, as expected. We improved the energy resolution by reducing the filling factor of inductor lines. The best energy resolution of 26 for the alpha particle of 5.49 MeV was observed in our device.