A Pulse Height Analyzer (PHA) is an instrument used in nuclear and elementary particle physics research which accepts electronic pulses of varying heights from particle and event detectors, digitizes the pulse heights, and saves the number of pulses of each height in registers or channels for later spectral analysis. Synonymous terms for 'Pulse Height Analysis' are; "pulse height spectrum" or "pulse height distribution." A PHA is a specific modification to MultiChannel Analyzers os Spectrometer.
A pulse height analyzer is also used as integrated into particle counters, or as a discrete module to calibrate particle counters.
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Pulse height analyzer Wikipedia(Text) CC BY-SA