Theoritical Considerations in the Design of Dead Time and Pileup Corrections in a Simple Two-Channel Digital Nuclear Radiation Measurement System

The sources of errors associated with the measurement of nuclear radiations includethe noise associated with the radiation pulse, the dead time required for the processing of the incident radiation pulse and the pileup of pulses. In analogue processing, these errors are often downplayed leading to appreciable errors in the observed results. Some digital processors have been designed and built aimed at solving these problems to a large extent but their complexities and high costs make them inaccessible for most laboratories especially in the developing countries. In this work, we have designed and implemented a cheaper digital nuclear radiation processing system that will significantly reduce these problems of errorsin nuclear spectroscopy. The processing scheme is based on digital pulse processing in both slow (energy) and fast (inspection) channels. The output of the fast channel is used for pileup inspection and slow channel peak capture while the slow channel provides for anaccurate pulse peak determination required for good energy resolution. The dead time effect is only restricted to the slow channel processing time which is the same as the pileup inspection time. The system functions in a non paralysable dead time effect manner with an appropriately derived dead time and pile-up error correction function.