Digital beta counting and pulse-shape analysis for high-precision nuclear beta decay half-life measurements: Tested on 26Alm

A digital beta-counting method has been developed for high-precision nuclear p decay half-life experiments that use a gas proportional counter. An 8-bit, 1-GS/s sampling-rate digitizer was used to record the waveforms from the detector and a software filter was designed, tested and applied successfully to discriminate genuine beta-decay events from spurious signals by pulse-shape analysis. The method of using a high-speed digitizer for precision p counting is described in detail. We have extensively tested the digitizer and the off-line filter by analyzing saved waveforms from the decay of Al-26(m) acquired at rates up to 10,000 per second. The half-life we obtain for Al-26(m) is 6345.30 +/- 0.90 ms, which agrees well with previous published measurements and is as precise as the best of them. This work demonstrates the feasibility of applying a high-speed digitizer and off-line digital signal processing techniques for highprecision nuclear beta-decay half-life measurements. (C) 2013 Elsevier B.V. All rights reserved.