MODERN PERFORMANCE CONTROL OF GAMMA-RAY SPECTROMETERS FOR INAA

An approach is presented for the performance control of gamma-ray spec trometers allowing for the identification of sources of malfunctioning . The traditional check consists of inspection of the FWHM of the peak s of the control source, their peak positions and areas followed by an energy calibration. The resolution and shape of a peak in the spectru m originating from an applied pulse generator are more responsive to t he electronic noise than the gamma-ray peaks. At the laboratory for IN AA in Delft, the traditional energy calibration has been replaced by a spectrometer performance control which complements the traditional me thod by (1) an analysis of the shape of the pulser peak, (2) an inspec tion of the low energy and high energy tails of the peaks, (3) specifi cation of quantified criteria for approval of the performance, (4) gen eration of control charts for visual inspection of the parameters dete rmined and (5) extensive documentation of all operational characterist ics for eventual correlations. This paper demonstrates how this approa ch to SPC enables to identify sources which cause malfunctioning of th e spectrometer.