High sensitivity phonon-mediated kinetic inductance detector with combined amplitude and phase read-out

L. Cardani, N. Casali, I. Colantoni, A. Cruciani, F. Bellini, M. G. Castellano, C. Cosmelli, A. D'Addabbo, S. Di Domizio, M. Martinez, C. Tomei, M. Vignati
2017 Applied Physics Letters  
The development of wide-area cryogenic light detectors with good energy resolution is one of the priorities of next generation bolometric experiments searching for rare interactions, as the simultaneous read-out of the light and heat signals enables background suppression through particle identification. Among the proposed technological approaches for the phonon sensor, the naturally-multiplexed Kinetic Inductance Detectors (KIDs) stand out for their excellent intrinsic energy resolution and
more » ... roducibility. To satisfy the large surface requirement (several cm^2) KIDs are deposited on an insulating substrate that converts the impinging photons into phonons. A fraction of phonons is absorbed by the KID, producing a signal proportional to the energy of the original photons. The potential of this technique was proved by the CALDER project, that reached a baseline resolution of 154±7 eV RMS by sampling a 2×2 cm^2 Silicon substrate with 4 Aluminum KIDs. In this paper we present a prototype of Aluminum KID with improved geometry and quality factor. The design improvement, as well as the combined analysis of amplitude and phase signals, allowed to reach a baseline resolution of 82±4 eV by sampling the same substrate with a single Aluminum KID.
doi:10.1063/1.4974082 fatcat:ysfbwse46bbfbhwl4rqpdymn64