Polycell: the elementary detection unit of the ISGRI CdTe gamma-ray camera

Citation
O. Limousin et al., Polycell: the elementary detection unit of the ISGRI CdTe gamma-ray camera, NUCL INST A, 458(1-2), 2001, pp. 551-557
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
ISSN journal
0168-9002 → ACNP
Volume
458
Issue
1-2
Year of publication
2001
Pages
551 - 557
Database
ISI
SICI code
0168-9002(20010201)458:1-2<551:PTEDUO>2.0.ZU;2-X
Abstract
A basic component called Polycell has been developed for the ISGRI CdTe gam ma -ray camera of the IBIS telescope on board the INTEGRAL satellite. This imager is an assembly of 16384 CdTe detectors (4 x 4 mm large, 2 mm thick) operating at room temperature. ISGRI covers the lower part (20 keV-l MeV) o f the IBIS energy range (20 keV-10 MeV). Detectors are arranged 4 x 4 on Po lycells, where they are connected to their front-end electronics. The front -end electronics is based on radiation tolerant 4-channel analog-digital AS ICs. The ASICs contain a low-noise charge-sensitive preamplifier (160e(-) r ms; 1 pF load) and a pulse rise-time measurement in addition to the standar d pulse-height measurement. This permits to compute a charge loss correctio n based on the charge drift time. The digital part includes the internal ac quisition timing sequence as well as the dialogue with external electronics . After a description of the front-end electronics, we will present the imp rovements made on the new and final version of this hybrid mini CdTe gamma -ray cameras. In conclusion, we will present the spectometric performance o btained owing to this modular device. A spectral resolution around 7% at 12 2keV is obtained with this last generation of ASICs. (C) 2001 Elsevier Scie nce B.V. All rights reserved.