Pile-up corrections for high-precision superallowed beta decay half-life measurements via gamma-ray photopeak counting

G. F. Grinyer*, C. E. Svensson, C. Andreoiu, A. N. Andreyev, R. A. E. Austin, G. C. Ball, D. Bandyopadhyay, R. S. Chakrawarthy, P. Finlay, P. E. Garrett, G. Hackman, B. Hyland, W. D. Kulp, K. G. Leach, J. R. Leslie, A. C. Morton, C. J. Pearson, A. A. Phillips, F. Sarazin, M. A. SchumakerM. B. Smith, J. J. Valiente-Dobon, J. C. Waddington, S. J. Williams, J. Wong, J. L. Wood, E. F. Zganjar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A general technique that corrects gamma-ray gated beta decay-curve data for detector pulse pile-up is presented. The method includes corrections for non-zero time-resolution and energy-threshold effects in addition to a special treatment of saturating events due to cosmic rays. This technique is verified through a Monte Carlo simulation and experimental data using radioactive beams of Na-26 implanted at the center of the 8 pi gamma-ray spectrometer at the ISAC facility at TRIUMF in Vancouver, Canada. The P-decay half-life of Na-26 obtained from counting 1809-keV gamma-ray photopeaks emitted by the daughter Mg-26 was determined to be T-1/2 = 1.07167 +/- 0.00055 s following a 27 sigma correction for detector pulse pile-up. This result is in excellent agreement with the result of a previous measurement that employed direct beta counting and demonstrates the feasibility of high-precision beta-decay half-life measurements through the use of high-purity germanium gamma-ray detectors. The technique presented here, while motivated by superallowed-Fermi P decay studies, is general and can be used for all half-life determinations (e.g. alpha-, beta-, X-ray, fission) in which a gamma-ray photopeak is used to select the decays of a particular isotope. (c) 2007 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)1005-1033
Number of pages29
JournalNuclear instruments & methods in physics research section a-Accelerators spectrometers detectors and associated equipment
Issue number3
Publication statusPublished - 11 Sept 2007


  • high-precision half-life measurements
  • detector pulse pile-up
  • O-14
  • gamma-ray counting

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