Alvaro Chavarria (U. Chicago) “Solid-State Imaging Detectors for Low-Energy Particle Physics”

Abstract:
The low noise, high spatial resolution and reliable performance of charge-coupled devices (CCDs) and complementary metal-oxide-semiconductor (CMOS) active-pixel sensors have made them detectors of choice for digital imaging. Although the slow time response of these devices has limited their application in high-energy particle physics, for the case of rare-event searches, where the particle interaction rate is extremely low, their properties can be fully exploited to build detectors that outperform in many aspects the traditional technologies of the field. I will present recent results from the DAMIC experiment, a low-mass dark matter search consisting of low-noise CCDs deployed in the SNOLAB laboratory. I will show how the exquisite spatial resolution of the detector allows for particle identification, and provides the unique capability to reject sequences of radioactive decay with utmost efficiency. These techniques can be extended to the search for neutrinoless double beta decay. I will present a recent proposal where we argue that a large array of amorphous Se-82 imagers based on CMOS technology could achieve the background levels necessary to test if neutrinos are Majorana fermions even in the case of a normal hierarchy of neutrino masses.