Digital Stabilization Algorithm for the Gamma Spectra of Scintillator Detectors in PGNAA

The drift of the acquired gamma spectra used in prompt gamma neutron activation analysis (PGNAA) has a large influence on the analysis accuracy. To address this problem, a set of digital algorithms for wide-region spectral stabilization was investigated. The spectra were first calibrated by using the nonlinear method, and the counts in each channel were corrected with cubic spline interpolation. Then, the corrected spectra were used for stabilization according to the established stabilization method. The experimental results showed a significant reduction in the maximum relative deviation of the peak position for both sodium iodide [NaI(Tl)] (7.26%–1.25%) and bismuth germanate oxide (BGO) (20.15%–2.91%) detectors.