Pile-up corrections for high-precision superallowed β decay half-life measurements via γ-ray photopeak counting
A general technique that corrects γ-ray gated β 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 26Na implanted at the center of the 8 π γ-ray spectrometer at the ISAC facility at TRIUMF in Vancouver, Canada. The β-decay half-life of 26Na obtained from counting 1809-keV γ-ray photopeaks emitted by the daughter 26Mg was determined to be T1 / 2 = 1.07167 ± 0.00055 s following a 27 σ correction for detector pulse pile-up. This result is in excellent agreement with the result of a previous measurement that employed direct β counting and demonstrates the feasibility of high-precision β-decay half-life measurements through the use of high-purity germanium γ-ray detectors. The technique presented here, while motivated by superallowed-Fermi β decay studies, is general and can be used for all half-life determinations (e.g. α-, β-, X-ray, fission) in which a γ-ray photopeak is used to select the decays of a particular isotope. © 2007 Elsevier B.V. All rights reserved.
Publication Source (Journal or Book title)
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Grinyer, G., Svensson, C., Andreoiu, C., Andreyev, A., Austin, R., Ball, G., Bandyopadhyay, D., Chakrawarthy, R., Finlay, P., Garrett, P., Hackman, G., Hyland, B., Kulp, W., Leach, K., Leslie, J., Morton, A., Pearson, C., Phillips, A., Sarazin, F., Schumaker, M., Smith, M., Valiente-Dobón, J., Waddington, J., Williams, S., Wong, J., Wood, J., & Zganjar, E. (2007). Pile-up corrections for high-precision superallowed β decay half-life measurements via γ-ray photopeak counting. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 579 (3), 1005-1033. https://doi.org/10.1016/j.nima.2007.05.323