You need JavaScript to view this

Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes

Abstract

The application of CdTe and CdZnTe detectors to medical X-ray Computed Tomography have been investigated. Different electrodes (Au, Pt, In) have been deposited on CdZnTe HPBM and on CdTe:ClTHM. Their injection properties have been determined with Current-Voltage characteristics. Under X-ray in CT conditions, injection currents measurements reveal trapped carriers space-charges formation. The same way, the comparisons of the responses to X-beam cut-off with various injection possibilities enable to follow the space-charges evolutions and then to determine the predominant traps types. Nevertheless, both hole and electron traps are responsible for the memory effect e.g. the currents levels dependence with irradiation history. This effect is noticed in particular on responses to fast flux variations that simulate scanner's conditions. Trap levels probably corresponding to native defects are responsible for these limitations. In order to make such detectors suitable for X-ray Computed Tomography, significant progresses in CdTe for CdZnTe crystal growth with an important defects densities reduction (factor 10), or possibly counting mode operation, seem necessary. (author)
Authors:
Publication Date:
Sep 28, 1999
Product Type:
Thesis/Dissertation
Report Number:
FRCEA-TH-757
Reference Number:
EDB-00:114329
Resource Relation:
Other Information: TH: These physique; PBD: 28 Sep 1999
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CDTE SEMICONDUCTOR DETECTORS; COMPUTERIZED TOMOGRAPHY; IMAGE SCANNERS; TRAPS; X-RAY DETECTION
OSTI ID:
20089073
Research Organizations:
CEA/Grenoble, Lab. d'Electronique, de Technologie et d'Instrumentation (LETI), 38 (France); Grenoble-1 Univ., 38 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR0002211040767
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
169 pages
Announcement Date:
Dec 19, 2000

Citation Formats

Ricq, St. Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes. France: N. p., 1999. Web.
Ricq, St. Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes. France.
Ricq, St. 1999. "Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes." France.
@misc{etde_20089073,
title = {Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes}
author = {Ricq, St}
abstractNote = {The application of CdTe and CdZnTe detectors to medical X-ray Computed Tomography have been investigated. Different electrodes (Au, Pt, In) have been deposited on CdZnTe HPBM and on CdTe:ClTHM. Their injection properties have been determined with Current-Voltage characteristics. Under X-ray in CT conditions, injection currents measurements reveal trapped carriers space-charges formation. The same way, the comparisons of the responses to X-beam cut-off with various injection possibilities enable to follow the space-charges evolutions and then to determine the predominant traps types. Nevertheless, both hole and electron traps are responsible for the memory effect e.g. the currents levels dependence with irradiation history. This effect is noticed in particular on responses to fast flux variations that simulate scanner's conditions. Trap levels probably corresponding to native defects are responsible for these limitations. In order to make such detectors suitable for X-ray Computed Tomography, significant progresses in CdTe for CdZnTe crystal growth with an important defects densities reduction (factor 10), or possibly counting mode operation, seem necessary. (author)}
place = {France}
year = {1999}
month = {Sep}
}