A novel technique of particle identification with bolometric detectors

TL;DR

This paper demonstrates that pulse shape analysis in scintillating bolometers can effectively distinguish between different particle types, aiding background reduction in rare event searches like neutrinoless double beta decay.

Contribution

It introduces a novel application of pulse shape analysis in bolometers with scintillating crystals for particle identification, which was not previously established.

Findings

Pulse shape analysis can differentiate electrons/gammas from alphas in bolometers.

Discrimination capability varies with absorber material.

Results support improved background rejection in rare event experiments.

Abstract

We report in this paper the proofs that the pulse shape analysis can be used in some bolometers to identify the nature of the interacting particle. Indeed, while detailed analyses of the signal time development in purely thermal detectors have not produced so far interesting results, similar analyses on bolometers built with scintillating crystals seem to show that it is possible to distinguish between an electron or gamma-ray and an alpha particle interaction. This information can be used to eliminate background events from the recorded data in many rare process studies, especially Neutrinoless Double Beta decay search. Results of pulse shape analysis of signals from a number of bolometers with absorbers of different composition (CaMoO4, ZnMoO4, MgMoO4 and ZnSe) are presented and the pulse shape discrimination capability of such detectors is discussed.