Title :
A scalable enhanced implementation of pulse shape analysis for 76Ge double-beta decay
Author :
Hossbach, Todd W. ; Aalseth, Craig E. ; Miley, Harry S.
Author_Institution :
Pacific Northwest Nat. Lab., Richland, WA, USA
Abstract :
Recent evidence for neutrino mass has resulted from numerous neutrino oscillation experiments. These results have prompted increased interest in neutrinoless double-beta decay (0ν ββ-decay). Unlike neutrino oscillation experiments, 0ν ββ-decay can probe the effective neutrino mass range suggested by oscillation results as well as the Majorana or Dirac nature of the neutrino. Searching for 0ν ββ-decay using HPGe spectrometers made of enriched (86%) 76Ge is a technique favored by current and next-generation experiments. The long half-lives of ββ decay makes detection challenging and low background levels necessary. With important remaining backgrounds due to cosmogenic activation products in the germanium itself (60Co,68Ge), techniques for discriminating background events from 0ν ββ-decay are critical. Previous work resulted in a technique which, by extracting interaction multiplicity from the shape of the current pulse evolved in an HPGe spectrometer, allowed discrimination of 0ν ββ-decay events with low interaction multiplicity from the expected background events having much higher interaction multiplicity. This work describes an enhanced implementation with faster algorithms and a scalable C++ architecture more suitable for next-generation experiments. The performance of this new implementation of a self-calibrating 3-D parametric discriminator is demonstrated and compared to the previous work.
Keywords :
beta-ray detection; beta-ray spectrometers; double beta decay; germanium radiation detectors; pulse analysers; 60Co; 68Ge; 76Ge double-beta decay; Dirac neutrino; HPGe spectrometers; Majorana neutrino; background event discrimination; cosmogenic activation products; current pulse shape analysis; effective neutrino mass; interaction multiplicity; long half-lives; low background levels; neutrino oscillation experiments; neutrinoless double-beta decay; scalable C++ architecture; self-calibrating 3-D parametric discriminator; Building materials; Germanium; Inductors; Laboratories; Neutrino sources; Physics; Probes; Pulse shaping methods; Shape; Spectroscopy;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2004 IEEE
Print_ISBN :
0-7803-8700-7
Electronic_ISBN :
1082-3654
DOI :
10.1109/NSSMIC.2004.1462399