title: Development of new CdZnTe detectors for room-temperature high-flux radiation measurements.
abstract: 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-2at 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 (241Am 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 (241Am 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 (57Co 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.
authors.affiliation: Dipartimento di Fisica e Chimica, University of Palermo, Viale delle Scienze, Edificio 18, Palermo 90128, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Abbene
authors.affiliation: Dipartimento di Fisica e Chimica, University of Palermo, Viale delle Scienze, Edificio 18, Palermo 90128, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Gerardi
authors.affiliation: Dipartimento di Fisica e Chimica, University of Palermo, Viale delle Scienze, Edificio 18, Palermo 90128, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Raso
authors.affiliation: Dipartimento di Fisica e Chimica, University of Palermo, Viale delle Scienze, Edificio 18, Palermo 90128, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Principato
authors.affiliation: Due2Lab srl, Via Paolo Borsellino 2, Scandiano, Reggio Emilia 42019, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Zambelli
authors.affiliation: Due2Lab srl, Via Paolo Borsellino 2, Scandiano, Reggio Emilia 42019, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Benassi
authors.affiliation: IMEM/CNR, Parco Area delle Scienze 37/A, Parma 43100, Italy.
authors.forename: Manuele
authors.initials: M
authors.lastname: Bettelli
authors.affiliation: IMEM/CNR, Parco Area delle Scienze 37/A, Parma 43100, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zappettini
keywords: CdZnTe detectors; X-ray and γ-ray detectors; digital pulse shape analysis; energy-resolved photon-counting detectors; gold electroless contact; high flux; travelling heater method