Open AccessDevelopment of new CdZnTe detectors for room‐temperature high‐flux radiation measurements
Author(s) -
Abbene Leonardo,
Gerardi Gaetano,
Raso Giuseppe,
Principato Fabio,
Zambelli Nicola,
Benassi Giacomo,
Bettelli Manuele,
Zappettini Andrea
Publication year - 2017
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577517000194
Subject(s) - full width at half maximum , preamplifier , detector , optoelectronics , materials science , anode , semiconductor detector , particle detector , planar , x ray detector , optics , physics , electrode , amplifier , cmos , computer graphics (images) , quantum mechanics , computer science
Recently, CdZnTe (CZT) detectors have been widely proposed and developed for room‐temperature X‐ray spectroscopy even at high fluxes, and great efforts have been made on both the device and the crystal growth technologies. In this work, the performance of new travelling‐heater‐method (THM)‐grown CZT detectors, recently developed at IMEM‐CNR Parma, Italy, is presented. Thick planar detectors (3 mm thick) with gold electroless contacts were realised, with a planar cathode covering the detector surface (4.1 mm × 4.1 mm) and a central anode (2 mm × 2 mm) surrounded by a guard‐ring electrode. The detectors, characterized by low leakage currents at room temperature (4.7 nA cm −2 at 1000 V cm −1 ), allow good room‐temperature operation even at high bias voltages (>7000 V cm −1 ). At low rates (200 counts s −1 ), the detectors exhibit an energy resolution around 4% FWHM at 59.5 keV ( 241 Am source) up to 2200 V, by using commercial front‐end electronics (A250F/NF charge‐sensitive preamplifier, Amptek, USA; nominal equivalent noise charge of 100 electrons RMS). At high rates (1 Mcounts s −1 ), the detectors, coupled to a custom‐designed digital pulse processing electronics developed at DiFC of University of Palermo (Italy), show low spectroscopic degradations: energy resolution values of 8% and 9.7% FWHM at 59.5 keV ( 241 Am source) were measured, with throughputs of 0.4% and 60% at 1 Mcounts s −1 , respectively. An energy resolution of 7.7% FWHM at 122.1 keV ( 57 Co source) with a throughput of 50% was obtained at 550 kcounts s −1 (energy resolution of 3.2% at low rate). These activities are in the framework of an Italian research project on the development of energy‐resolved photon‐counting systems for high‐flux energy‐resolved X‐ray imaging.