Implementation of a conditioning circuit for radiation detectors

In this paper are presented the results achieved in the implementation of a measurement and conditioning circuit for solid-state radiation detectors used in measurement/monitoring of neutrons/gamma radiation fluxes generated by nuclear plants or other radioactive sources. In comparison with other implementations, the proposed detector has the advantage of a compact realization and an improved sensitivity. Also, the circuit is designed to be integrated in a distributed radiation monitoring system with wireless transmission. The conditioning circuit makes the primary processing of the signal from detector and is compose by a low noise transconductance preamplifier followed by a band-pass active filter and a comparator for pulses discrimination. The transconductance preamplifier realizes the charge-to-voltage conversion, for different values of charge variation that correspond to different energy ranges of nuclear radiations. The behavior of the proposed conditioning circuit was simulated in Pspice simulator and was analyzed relative to various operation conditions. Also, the conditioning circuit was implemented in SMD technology and the prototype was extensively tested taking into consideration different radiation energy levels and ambient temperature changes.