RSC Seminar

概要

“Title: Development of Radiation Detectors and Signal Processing Techniques Speaker: M. Nakhostin, Department of Physics, University of Surrey, UK

Abstract: In this talk, I will present the results of my research on the development of radiation detectors and signal processing techniques in the following areas: • First, the results of the calculations of output pulses from semiconductor detectors by using the Shockley-Ramo theorem are described. We particularly focus on the inclusion of the length of ionization track inside the detectors to the calculation of output pulses from diamond and compound semiconductor detectors [1,2]. The effects of front-end electronics and various sources of electronic noise (thermal, shot, and 1/f noise) are also included in the simulations. • The second part of this talk is about the development of digital signal processing techniques. Computationally economic algorithms for CR-(RC)n pulse shaping, gated integrators, timing with fast scintillators as well as slow semiconductor detectors, and high-rate operation of scintillators will be described [3-9]. • In the third part, I will describe a method for the identification of low intensity γ-ray peaks in the energy spectra of low energy resolution scintillation detectors such as NaI(Tl). Such scintillator detectors are widely used in environmental monitoring applications and portal monitors, where the limited number of events can impose a serious challenge for the identification of radioisotopes. • The last part of this talk is devoted to the development of neutron and gamma-ray detectors by employing new scintillator crystals such as GAGG and SrI2:Eu, coupled to silicon photomultipliers (SiPMs). The spectroscopic performance of the SrI2:Eu/SiPM was particularly studied for the development of a drone deployable radiation detection system. The GAGG scintillator was also studied for the detection of thermal neutrons due to its large content of gadolinium. The GAGG scintillator in a phoswich dual-mode neutron/gamma detector is described as well.

References [1] M. Nakhostin, Charged particle response of transmission diamond detectors, Nucl. Instrum. and Meth. A Vol. 703 (2013) 199. [2] M. Nakhostin, A Esmaili-Torshabi, The influence of electron track lengths on the γ-ray response of compound semiconductor detectors, Nucl. Instrum. and Meth. A Vol. 797 (2015) 255. [3] M. Nakhostin, Recursive Algorithms for Real-Time Digital Pulse Shaping, IEEE Trans. on Nucl. Sci. Vol. 58 (2011) 2378. [4] M. Nakhostin, Recursive algorithms for digital implementation of neutron/gamma discrimination in liquid scintillation detectors, Nucl. Instrum. and Meth. A, Vol. 672 (2012) 1. [5] M. Nakhostin, et al., Digital processing of signals from LaBr3:Ce scintillation detectors, J. of Instrumentation, Vol. 9 (2014) C12049. [6] M. Nakhostin, A comparison of digital zero-crossing and charge-comparison methods for neutron/γ-ray discrimination with liquid scintillation detectors, Nucl. Instrum. and Meth. A Vol.797 (2015) 77. [7] M. Nakhostin, A digital pulse shortening method for the mitigation of pulse pile-up effect in scintillation radiation detectors, J. of Instrumentation, Vol. 14 (2019) P04012 [8] M. Nakhostin, A General-Purpose Digital Pulse Shape Discrimination Algorithm, IEEE Trans. on Nucl. Sci. Vol. 66 (2019) 838. [9] M. Nakhostin, Digital pulse timing with semiconductor gamma-ray detectors using a wavelet transform technique, Rev. of Sci. Instrum., Vol. 89 (2018) 103303