Novel technique for the study of pile-up events in cryogenic bolometers

TL;DR

This paper introduces a new method to generate controlled pile-up events in cryogenic bolometers, enabling better benchmarking of pile-up rejection techniques crucial for neutrinoless double-beta decay experiments.

Contribution

It presents a novel approach using a programmable waveform generator to produce reproducible pile-up events for detector analysis.

Findings

Achieved 90% rejection efficiency for pile-up events with 2ms separation.

Demonstrated the technique with a detector array at Gran Sasso.

Optimized analysis strategies for background discrimination.

Abstract

Precise characterization of detector time resolution is of crucial importance for next-generation cryogenic-bolometer experiments searching for neutrinoless double-beta decay, such as CUPID, in order to reject background due to pile-up of two-neutrino double-beta decay events. In this paper, we describe a technique developed to study the pile-up rejection capability of cryogenic bolometers. Our approach, which consists of producing controlled pile-up events with a programmable waveform generator, has the benefit that we can reliably and reproducibly control the time separation and relative energy of the individual components of the generated pile-up events. The resulting data allow us to optimize and benchmark analysis strategies to discriminate between individual and pile-up pulses. We describe a test of this technique performed with a small array of detectors at the Laboratori Nazionali del Gran Sasso, in Italy; we obtain a 90% rejection efficiency against pulser-generated pile-up events with rise time of ~15ms down to time separation between the individual events of about 2ms.