Comparison of a digital and an analog signal processing system for neutron inelastic gamma-ray spectrometry

We compared the value of using a digital signal processing unit for gamma-ray spectroscopy with that of an analog one for in situ measurements of gamma-rays generated by inelastic neutron scattering reactions with soil elements. A large cylindrical NaI(Tl) scintillation detector, 15.24 cm high by 15.24 cm diameter was used to measure carbon (C) and oxygen (O). The performance of the systems was assessed as a function of input count rate (ICR) by monitoring the peak areas of the C, 4.43 MeV, and O, 6.13 MeV, gamma-rays. In separate experiments, the digital and the analog systems were also compared using an intense 10.3 mCi 137Cs source to vary the ICR, and the 1.17 MeV peak area of 60Co was used as the reference.