Performance of a large area photon detector for rare event search applications
C. W. Fink, S. L. Watkins, T. Aramaki, P. L. Brink, J. Camilleri, X. Defay, S. Ganjam, Yu. G. Kolomensky, R. Mahapatra, N. Mirabolfathi, W. A. Page, R. Partridge, M. Platt, M. Pyle, B. Sadoulet, B. Serfass, S. Zuber, (CPD Collaboration)
Abstract
We present the design and characterization of a large-area Cryogenic PhotoDetector designed for active particle identification in rare event searches, such as neutrinoless double beta decay and dark matter experiments. The detector consists of a 45.6 cm2 surface area by a 1-mm-thick 10.6 g Si wafer. It is instrumented with a distributed network of Quasiparticle-trap-assisted Electrothermal feedback Transition-edge sensors with superconducting critical temperature Tc=41.5 mK to measure athermal phonons released from interactions with photons. The detector is characterized and calibrated with a collimated 55Fe x-ray source incident on the center of the detector. The noise equivalent power is measured to be 1×10−17 W/Hz in a bandwidth of 2.7 kHz. The baseline energy resolution is measured to be σE=3.86±0.04 (stat.)−0.00+0.19 (syst.) eV. The detector also has an expected timing resolution of σt=2.3 μs for 5 σE events.