Extraordinary improvement in scintillation detectors via post-processing with ASEDRA—solution to a 50-year-old problem

摘要

We have developed a ground-breaking algorithm, ASEDRA, to post-process scintillator detector spectra to renderphotopeaks with high accuracy. The post-processed spectrum is comparable with resolved full energy peaks rendered byhigh resolution HPGe semiconductor detectors. ASEDRA, or Advanced Synthetically Enhanced Detector ResolutionAlgorithm, is currently applied to NaI(Tl) detectors, which are robust, but suffer from poor energy resolution.ASEDRA rapidly post-processes a NaI(1) detector spectrum over a few seconds on a standard laptop without priorknowledge of sources or spectrum features. ASEDRA incorporates a novel denoising algorithm based on an adaptiveChi-square methodology called ACHIP, or Adaptive Chi-quare Processed denoising. Application of ACHIP isnecessary to remove stochastic noise, yet preserve fine detail, and can be used as an independent tool for general noisereduction. Following noise removal, ASEDRA sequentially employs an adaptive detector response algorithm to removethe spectrum attributed to specific gammas. Tests conducted using a 2"x2" NaI(Tl) detector, along with a HPGedetector demonstrate the accuracy of ASEDRA; in this paper, we present results using a (152)usource. Analysis ofASEDRA results show correct identification of at least 15 photopeaks from (152)Eu,with relative yield ratios of majorlines to better than a factor of two for most cases (referencing the (152)u344 keV photopeak), enabling better than afactor of four improvement in resolving peaks compared with unprocessed NaI(Tl). Moreover, denoising and syntheticresolution enhancement algorithms can be adapted to any detector. ACHIP and ASEDRA are covered under aProvisional Patent, Registration Number #60/971,770, 9/12/2007, USPO.