Position and energy-resolved particle detection using phonon-mediated microwave kinetic inductance detectors

Abstract

We demonstrate position and energy-resolved phonon-mediated detection of particle interactions in a silicon substrate instrumented with an array of microwave kinetic inductance detectors (MKIDs). The relative magnitude and delay of the signal received in each sensor allows the location of the interaction to be determined with 1 mm resolution at 30 keV. Using this position information, variations in the detector response with position can be removed, and an energy resolution of σ E = 0.55 keV at 30 keV was measured. Since MKIDs can be fabricated from a single deposited film and are naturally multiplexed in the frequency domain, this technology can be extended to provide highly-pixelized athermal phonon sensors for ∼1 kg scale detector elements. Such high-resolution, massive particle detectors would be applicable to rare-event searches such as the direct detection of dark matter, neutrinoless double-beta decay, or coherent neutrino-nucleus scattering.Next generation rare-event searches such as the direct detection of dark matter require large target masses (∼10 3 kg) with sub-keV energy resolution. This requires increasing the mass of current solid-state, cryogenic experiments 1,2 by 2 orders of magnitude, while maintaining the background-free operation of existing detectors. Reducing the cost and time needed to fabricate and test each detector element is necessary for such large cryogenic experiments to be feasible.Detectors that measure both the athermal phonons and ionization created by a particle interaction have demonstrated sufficient background rejection to enable next-generation experiments 3 . Microwave kinetic inductance detectors (MKIDs) 4,5 offer several advantages for providing athermal phonon sensors in large experiments relative to the transition edge sensor (TES)-based designs currently in use 1,2,6 . MKIDs can be patterned from a single deposited aluminum film, with large (>10 µm) features, significantly reducing fabrication time and complexity. Since MKIDs are naturally multiplexed in the frequency domain, hundreds of sensors can be read out on a single coaxial cable, enabling a more granular phonon sensor that is expected to provide enhanced background rejection. In addition to dark matter direct detection, high-resolution, massive particle detectors are applicable to the detection of neutrinoless double-beta decay 7 and coherent neutrino-nucleus scattering 8 .Previous designs 9-11 attempted to absorb the incident energy in large-area collectors coupled to smaller volume, distributed MKIDs. Although separating the absorber and sensor allowed increased sensitivity by concentrating the absorbed energy, test devices suffered from poor transmission of quasiparticles from the absorber to sensor. Here we present a simplified design that eliminates the absorber by directly collecting the energy using large-area MKIDs. A similar design developed independently by Swenson et al. 12 has been used a) Electronic mail: davidm@caltech.edu to demonstrate time-resolved phonon-mediated detection of high-energy int...

Electrothermal model of kinetic inductance detectors

“…Kinetic Inductance Detectors (KIDs) [1,2,3,4] comprise a superconducting thin-film microwave resonator connected to an optical or submillimetre-wave absorber of some kind. The resonator operates at a temperature T well below the superconducting transition temperature T C : T /T C ≈ 0.1.…”

X-ray photon detection using superconducting resonators in thermal quasi-equilibrium

“…We attribute these pulses primarily to absorption of photons in the SiN membrane with subsequent generation of athermal phonons. These athermal phonons are energetic enough to generate a large number of non-equilibrium quasiparticles, which results in a large response [10,11] and a very short decay time in tungsten silicide. For the tantalum device on the perforated SiN membrane, these pulses have a second decay time, which is likely due to phonon trapping or thermalization in the SiN, given the very weak thermal link to bath.…”

Design and Fabrication of Microwave Kinetic Inductance Detectors using NbN Symmetric Spiral Resonator Array

“…2 shows the simulated transmission (S 21 ) response of a spiral resonator for the spiral-MKID. We observed a sharp resonance around 4.498 GHz and obtained maximum attenuation (A max ) of over 20 dB and an unloaded quality factor (Q u ) of over 5×10 4 . Fig.…”

“…Furthermore, they can be easily made with a single layer of superconducting film deposited on a substrate and patterned using conventional optical lithography. Research groups have been developing MKIDs for sub-millimeter astronomy [2], optical astronomy [3], and dark matter detection experiments [4] in recent years. These MKIDs require an operating temperature of 0.1 K, which is attained using expensive dilution refrigerators or adiabatic demagnetization refrigerators.…”