Absorber-coupled lumped element kinetic inductance detectors for gamma-rays

We propose gamma-ray detectors based on superconducting resonators that can be largely multiplexed and show potential for quick response time, high spatial resolution, and high energy resolution. The resonators were fabricated with a niobium film on a silicon wafer. Eight out of ten detectors could be operated at 0.3 K. The detectors were coupled to a 2-mm-thick lead absorber and examined with a cesium 137 source. The pulse decay time was 3.6 µs and energy resolution was 3.8 keV at 662 keV. We also describe the resonant properties of each detector. The proposed detectors are suitable for use as food-screening systems.