Pulse shape discrimination studies with a Broad-Energy Germanium detector for signal identification and background suppression in the GERDA double beta decay experiment

Abstract

First studies of event discrimination with a Broad-Energy Germanium (BEGe) detector are presented. A novel pulse shape method, exploiting the characteristic electrical field distribution inside BEGe detectors, allows to identify efficiently single-site events and to reject multi-site events. The first are typical for neutrinoless double beta decays (0-nu-2-beta) and the latter for backgrounds from gamma-ray interactions. The obtained survival probabilities of backgrounds at energies close to Q(76Ge) = 2039 keV are 0.93% for events from 60Co, 21% from 226Ra and 40% from 228Th. This background suppression is achieved with 89% acceptance of 228Th double escape events, which are dominated by single site interactions. Approximately equal acceptance is expected for 0-nu-2-beta-decay events. Collimated beam and Compton coincidence measurements demonstrate that the discrimination is largely independent of the interaction location inside the crystal and validate the pulse-shape cut in the energy range of Q(76Ge). The application of BEGe detectors in the GERDA and the Majorana double beta decay experiments is under study.

22 pages, 16 figures, submitted to JINST: JINST_018P_0809

References in corpus (12)

• Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics
• A New 76Ge Double Beta Decay Experiment at LNGS
• Identification of photons in double beta-decay experiments using segmented germanium detectors - studies with a GERDA Phase II prototype detector
• The Majorana Project
• Pulse shapes from electron and photon induced events in segmented high-purity germanium detectors
• Background reduction and sensitivity for germanium double beta decay experiments
• LArGe: Background suppression using liquid argon (LAr) scintillation for 0$\nu \beta \beta$ decay search with enriched germanium (Ge) detectors
• TThe {\sc Majorana} Project
• MaGe - a Geant4-based Monte Carlo framework for low-background experiments
• Test of pulse shape analysis using single Compton scattering events
• Pulse Shape Analysis with a Broad-Energy Germanium Detector for the GERDA experiment
• Search for neutrinoless double-beta decay of Ge-76 with GERDA

Cited by in corpus (49)

• Neutrinoless Double-Beta Decay: Status and Prospects
• Results on neutrinoless double beta decay of 76Ge from GERDA Phase I
• Final Results of GERDA on the Search for Neutrinoless Double-$\beta$ Decay
• Background free search for neutrinoless double beta decay with GERDA Phase II
• The GERDA experiment for the search of 0νββ decay in ^{76}Ge
• Final Result of the MAJORANA DEMONSTRATOR's Search for Neutrinoless Double-$\beta$ Decay in ${}^{76}$Ge
• Recent Progress in Double Beta Decay
• Pulse shape discrimination for GERDA Phase I data
• Production, characterization and operation of ${}^{76}$Ge enriched BEGe detectors in GERDA
• Sense and sensitivity of double beta decay experiments
• Neutrinoless Double Beta-Decay
• The Majorana Experiment
• An Improved Limit on Pauli-Exclusion-Principle Forbidden Atomic Transitions
• Characterization of a broad energy germanium detector and application to neutrinoless double beta decay search in Ge-76
• Mitigation of ${}^{42}$Ar/${}^{42}$K background for the GERDA Phase II experiment
• Characterization of 30 ${}^{76}$Ge enriched Broad Energy Ge detectors for GERDA Phase II
• Initial Results from the MAJORANA DEMONSTRATOR
• Off-line data processing and analysis for the GERDA experiment
• Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge-76
• Determining the Drift Time of Charge Carriers in P-Type Point-Contact HPGe Detectors
• Ge Detectors and $0\nu \beta \beta$: The Search for Double Beta Decay with Germanium Detectors: Past, Present and Future
• Pulse shape analysis in GERDA Phase II
• HEROICA: an Underground Facility for the Fast Screening of Germanium Detectors
• GELATIO: a general framework for modular digital analysis of high-purity Ge detector signals
• $\alpha$-event Characterization and Rejection in Point-Contact HPGe Detectors
• Improving Photoelectron Counting and Particle Identification in Scintillation Detectors with Bayesian Techniques
• Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector
• Search for Neutrinoless Double-Beta Decay of ${}^{76}$Ge with a Natural Broad Energy Germanium Detector
• Neutrinoless Double Beta Decay with Germanium Detectors: 10${}^{26}$ yr and Beyond
• Characterization of inverted coaxial ${}^{76}$Ge detectors in GERDA for future double-$\beta$ decay experiments
• Pulse shape discrimination for the CONUS experiment in the keV and sub-keV regime
• Charge-carrier collective motion in germanium detectors for ββ-decay searches
• Searching for ${}^{76}$Ge neutrinoless double beta decay with the CDEX-1B experiment
• Isotopically modified Ge detectors for {\sc Gerda}: from production to operation
• Neutrinoless double beta decay
• Status of double beta decay experiments using isotopes other than Xe-136
• Double Beta Decay Experiments at Canfranc Underground Laboratory
• Background Rejection of n${}^{+}$ Surface Events in GERDA Phase II
• The Status and Initial Results of the MAJORANA DEMONSTRATOR Experiment
• Neutrinoless double beta decay: searching for new physics with comparison of different nuclei
• Characterization study of a broad-energy germanium detector at CJPL
• A feasibility study of multi-electrode high-purity germanium detector for Ge-76 neutrinoless double beta decay searching
• The Majorana Demonstrator search for neutrinoless double beta decay
• Topologies of ${}^{76}$Ge double-beta decay events and calibration procedure biases
• Radiopurity screening of materials for rare event searches by neutron activation at the TRIGA reactor of Pavia
• Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR
• GeFRO: a New Charge Sensitive Amplifier Design with a Minimal Number of Front-end Components
• Compton suppression in BEGe detectors by digital pulse shape analysis
• Status Update of the MAJORANA DEMONSTRATOR Neutrinoless Double Beta Decay Experiment