Design and Characterization of a Phonon-Mediated Cryogenic Particle Detector with an eV-Scale Threshold and 100 keV-Scale Dynamic Range

TL;DR

This paper reports the development of a cryogenic silicon detector with eV-scale sensitivity and a 100 keV dynamic range, suitable for dark matter and neutrino detection, achieving high energy resolution and low thresholds.

Contribution

The paper introduces a novel phonon-sensitive detector exploiting the Neganov-Trofimov-Luke effect with record low energy threshold and high resolution at cryogenic temperatures.

Findings

Achieved 2.65 eV phonon energy resolution without bias

Demonstrated 9.2 eV detection threshold with offline filtering

Calibrated energy scale up to 120 keV

Abstract

We present the design and characterization of a cryogenic phonon-sensitive 1-gram Si detector exploiting the Neganov-Trofimov-Luke effect to detect single-charge excitations. This device achieved 2.65(2)~eV phonon energy resolution when operated without a voltage bias across the crystal and a corresponding charge resolution of 0.03 electron-hole pairs at 100~V bias. With a continuous-readout data acquisition system and an offline optimum-filter trigger, we obtain a 9.2~eV threshold with a trigger rate of the order of 20~Hz. The detector's energy scale is calibrated up to 120~keV using an energy estimator based on the pulse area. The high performance of this device allows its application to different fields where excellent energy resolution, low threshold, and large dynamic range are required, including dark matter searches, precision measurements of coherent neutrino-nucleus scattering, and ionization yield measurements.