Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

$$$$\alpha $$$$-event characterization and rejection in point-contact HPGe detectors

Journal Article · · European Physical Journal. C, Particles and Fields
Abstract

P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector’s response to $$$$\alpha $$$$ α particles incident on the sensitive passivated and p $$^+$$ + surfaces, a previously poorly-understood source of background. The detector studied is identical to those in the Majorana Demonstrator experiment, a search for neutrinoless double-beta decay ( $$$$0\nu \beta \beta $$$$ 0 ν β β ) in $$$$^{76}$$$$ 76 Ge. $$$$\alpha $$$$ α decays on most of the passivated surface exhibit significant energy loss due to charge trapping, with waveforms exhibiting a delayed charge recovery (DCR) signature caused by the slow collection of a fraction of the trapped charge. The DCR is found to be complementary to existing methods of $$$$\alpha $$$$ α identification, reliably identifying $$$$\alpha $$$$ α background events on the passivated surface of the detector. We demonstrate effective rejection of all surface $$$$\alpha $$$$ α events (to within statistical uncertainty) with a loss of only 0.2% of bulk events by combining the DCR discriminator with previously-used methods. The DCR discriminator has been used to reduce the background rate in the $$$$0\nu \beta \beta $$$$ 0 ν β β region of interest window by an order of magnitude in the Majorana Demonstrator   and will be used in the upcoming LEGEND-200 experiment.

Research Organization:
Duke Univ., Durham, NC (United States). Triangle Universities Nuclear Laboratory; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); University of North Carolina, Chapel Hill, NC (United States)
Sponsoring Organization:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), High Energy Physics (HEP); USDOE Office of Science (SC), Nuclear Physics (NP)
Contributing Organization:
Majorana Collaboration
Grant/Contract Number:
89233218CNA000001; AC02-05CH11231; AC02-76SF00515; AC05-00OR22725; AC05-76RL01830; FG02-97ER41020; FG02-97ER41033; FG02-97ER41041; SC0012612; SC0014445; SC0018060
OSTI ID:
1854947
Alternate ID(s):
OSTI ID: 1862683
OSTI ID: 1864992
OSTI ID: 1867256
OSTI ID: 1870698
OSTI ID: 1887675
OSTI ID: 1670140
OSTI ID: 1896677
OSTI ID: 23132882
OSTI ID: 1907797
Report Number(s):
LA-UR-20-24209; PNNL-SA-153353; 226; PII: 10161
Journal Information:
European Physical Journal. C, Particles and Fields, Journal Name: European Physical Journal. C, Particles and Fields Journal Issue: 3 Vol. 82; ISSN 1434-6044
Publisher:
Springer Science + Business MediaCopyright Statement
Country of Publication:
Germany
Language:
English

References (30)

Review of the Shockley–Ramo theorem and its application in semiconductor gamma-ray detectors journal May 2001
ROOT — An object oriented data analysis framework journal April 1997
Nuclear Data Sheets for A = 237 journal August 2006
Limits and confidence intervals in the presence of nuisance parameters
  • Rolke, Wolfgang A.; López, Angel M.; Conrad, Jan
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 551, Issue 2-3 https://doi.org/10.1016/j.nima.2005.05.068
journal October 2005
Computational models of germanium point contact detectors
  • Mullowney, Paul; Lin, Ming-Chieh; Paul, Kevin
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 662, Issue 1 https://doi.org/10.1016/j.nima.2011.09.061
journal January 2012
Characteristics of signals originating near the lithium-diffused N+ contact of high purity germanium p-type point contact detectors
  • Aguayo, E.; Amman, M.; Avignone, F. T.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 701 https://doi.org/10.1016/j.nima.2012.11.004
journal February 2013
Impact of ADC non-linearities on the sensitivity to sterile keV neutrinos with a KATRIN-like experiment
  • Dolde, Kai; Mertens, Susanne; Radford, David
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 848 https://doi.org/10.1016/j.nima.2016.12.015
journal March 2017
Alpha-event and surface characterisation in segmented true-coaxial HPGe detectors
  • Abt, I.; Garbini, L.; Gooch, C.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 858 https://doi.org/10.1016/j.nima.2017.03.057
journal June 2017
Pulse shape discrimination performance of inverted coaxial Ge detectors
  • Domula, A.; Hult, M.; Kermaïdic, Y.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 891 https://doi.org/10.1016/j.nima.2018.02.056
journal May 2018
Characterization of high purity germanium point contact detectors with low net impurity concentration
  • Mertens, S.; Hegai, A.; Radford, D. C.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 921 https://doi.org/10.1016/j.nima.2018.09.012
journal March 2019
SRIM – The stopping and range of ions in matter (2010)
  • Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
  • Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12 https://doi.org/10.1016/j.nimb.2010.02.091
journal June 2010
Background-free search for neutrinoless double-β decay of 76Ge with GERDA journal April 2017
Large-mass ultralow noise germanium detectors: performance and applications in neutrino and astroparticle physics journal September 2007
MAJORANA Collaboration's Experience with Germanium Detectors journal May 2015
Pulse shape discrimination studies with a Broad-Energy Germanium detector for signal identification and background suppression in the GERDA double beta decay experiment journal October 2009
Search for neutrinoless double- β decay in Ge 76 with 26 kg yr of exposure from the Majorana Demonstrator journal August 2019
Multisite event discrimination for the majorana demonstrator journal June 2019
Neutrinoless double- β decay in SU(2)×U(1) theories journal June 1982
Review of Particle Physics journal August 2018
Publisher’s Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett.117, 082503 (2016)] journal September 2016
New Limits on Bosonic Dark Matter, Solar Axions, Pauli Exclusion Principle Violation, and Electron Decay from the Majorana Demonstrator journal April 2017
Improved Limit on Neutrinoless Double- β Decay of Ge 76 from GERDA Phase II journal March 2018
Final Results of GERDA on the Search for Neutrinoless Double- β Decay journal December 2020
Low capacitance large volume shaped-field germanium detector journal January 1989
Probing Majorana neutrinos with double-β decay journal September 2019
Pulse shape discrimination for Gerda Phase I data journal October 2013
Neutrinoless Double-Beta Decay: Status and Prospects journal October 2019
Pulse Shape Analysis for the GERDA Experiment to Set a New Limit on the Half-life of Neutrinoless Double Beta Decay of Ge-76 text January 2017
Possibilities of Future Double Beta Decay Experiments to Investigate Inverted and Normal Ordering Region of Neutrino Mass journal January 2019
Surface Characterization of P-Type Point Contact Germanium Detectors journal October 2021

Similar Records

Latest Results from the CUORE Experiment
Journal Article · Fri Oct 07 20:00:00 EDT 2022 · Journal of Low Temperature Physics · OSTI ID:1891536

Final results on the $$0\nu \beta \beta $$ decay half-life limit of $$^{100}$$Mo from the CUPID-Mo experiment
Journal Article · Mon Nov 14 19:00:00 EST 2022 · European Physical Journal. C, Particles and Fields (Online) · OSTI ID:1898240

Search for double-beta decay of $$\mathrm {^{130}Te}$$ to the $$0^+$$ states of $$\mathrm {^{130}Xe}$$ with CUORE
Journal Article · Wed Jun 30 20:00:00 EDT 2021 · European Physical Journal. C, Particles and Fields · OSTI ID:1804918