Digital pulse processing and optimization of the front-end electronics for nuclear instrumentation

C. Bobin (1) , J. Bouchard (1) , C. Thiam (1) , Y. Ménesguen (1)

1 LNHB - Laboratoire National Henri Becquerel

This article describes an algorithm developed for the digital processing of signals provided by a high efficiency well-type NaI(Tl) detector used to apply the 4$\pi \gamma$ technique. In order to achieve a low-energy threshold, a new front-end electronics has been specifically designed to optimize the coupling to an analog-to-digital converter (14 bit, 125 MHz) connected to a digital development kit produced by Altera (c) . The digital pulse processing is based on an IIR (Infinite Impulse Response) approximation of the Gaussian filter (and its derivatives) that can be applied to the real-time processing of digitized signals. Based on measurements obtained with the photon emissions generated by an $^{241}$Am source, the energy threshold is estimated to be equal to ~2 keV corresponding to the physical threshold of the NaI (Tl) detector. An algorithm developed for a Silicon Drift Detector used for low-energy x-ray spectrometry is also described. In that case, the digital pulse processing is specifically designed for signals provided by a reset-type preamplifier (${55}$Fe source).

Keywords: Digital pulse processing; Front-end electronics; Gaussian filter; Radionuclide metrology

Domains: Instrumentation and Detectors [physics.ins-det]; Nuclear Experiment [nucl-ex]; Micro and nanotechnologies/Microelectronics

C. Bobin, J. Bouchard, C. Thiam, Y. Ménesguen. Digital pulse processing and optimization of the front-end electronics for nuclear instrumentation. Applied Radiation and Isotopes, 2014, 87, pp.195 - 199. ⟨10.1016/j.apradiso.2013.11.090⟩. ⟨cea-01828386⟩