Search results for "CDT"
showing 10 items of 32 documents
The Efficacy of an Experimental Single Solution versus Alternate Use of Multiple Irrigants on Root Dentin Microhardness
2013
The objective of this work was to use fnite element analysis to compare the effect of forces coming to bear on abutments 4.1 or 5.0 mm in diameter connThis study was carried-out to evaluate and compare the efficacy of various irrigants when used singly or in combination on the microhardness of root canal dentin. Study Design: A total of 50 root-halves were randomly divided into 5 groups immediately after the initial baseline microhardness measurements and treated with: Group-1; 7.5%Ethylenediaminetetraaceticacid (EDTA)+ 2.5%sodium hypochlorite (NaOCl), Group-2; 7.5%ethyleneglycol-bis[b-aminoethylether]-N, N,N0,N0-tetraaceticacid (EGTA)+ 2.5%NaOCl, Group-3; 7.5%trans1,2diaminocyclohexane NNN…
Recent trends in the development of CdTe and CdZnTe semiconductor detectors for astrophysical applications
2010
Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) offer great promise as x-ray and gamma ray detectors. Due to the high detection efficiency, the good room temperature performance and the recent improvements on crystal growth technology, CdTe and CdZnTe detectors have obtained an increasing interest in the field of hard x-ray and gamma ray astronomy. In this paper, we report on the R&D activities on CdTe and CdZnTe detectors for high energy space instrumentation. Our group has been involved in the design of new multilayer hard x and soft gamma ray Laue lens telescopes and, in particular on the development of focal plane detectors based on CdTe and CdZnTe. Here we present the acti…
Aspetti medico legali dei "nuovi" biomarkers dell'abuso cronico di alcool in vivente e cadavere
2008
gli Autori analizzano gli aspetti medico legali dei "nuovi" biomarkers dell'abuso cronico di alcool in vivente e cadavere. Fra questi, l'utilizzo del dosaggio della CDT, potrebbe trovare una importante valenza in tema di accertamenti idoneativi alla guida in soggetti assuntori periodici o cronici di alcool
Charge Sharing and Cross Talk Effects in High-Z and Wide-Bandgap Compound Semiconductor Pixel Detectors
2023
Intense research activities have been made in the development of high-Z and wide-bandgap compound semiconductor pixel detectors for the next generation X-ray and gamma ray spectroscopic imagers. Cadmium telluride (CdTe) and cadmium-zinc-telluride (CdZnTe or CZT) pixel detectors have shown impressive performance in X-ray and gamma ray detection from energies of few keV up to 1 MeV. Charge sharing and cross-talk phenomena represent the typical drawbacks in sub-millimeter pixel detectors, with severe distortions in both energy and spatial resolution. In this chapter, we review the effects of these phenomena on the response of CZT/CdTe pixel detectors, with particular emphasis on the current st…
Ballistic Deficit Pulse Processing in Cadmium-Zinc-Telluride Pixel Detectors for High-Flux X-ray Measurements.
2022
High-flux X-ray measurements with high-energy resolution and high throughput require the mitigation of pile-up and dead time effects. The reduction of the time width of the shaped pulses is a key approach, taking into account the distortions from the ballistic deficit, non-linearity, and time instabilities. In this work, we will present the performance of cadmium–zinc–telluride (CdZnTe or CZT) pixel detectors equipped with digital shapers faster than the preamplifier peaking times (ballistic deficit pulse processing). The effects on energy resolution, throughput, energy-linearity, time stability, charge sharing, and pile-up are shown. The results highlight the absence of time instabilities …
CDTE AND CDZNTE PIXEL DETECTORS FOR X-RAY SPECTROSCOPIC IMAGING
2012
Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors for x-ray detectors have experienced a rather rapid development in the last few years. Among the traditional x-ray detectors based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show higher detection efficiency at high energies and good room temperature performance and are well suited for the development of compact detection systems and pixel arrays for simultaneous measurements of photon interaction position and energy. This chapter is an introduction to the physics and the technology of CdTe and CdZnTe pixel detectors for x-ray spectroscopy and imaging. The physical properties of CdTe …
Time-dependent current-voltage characteristics of Al/p-CdTe/Pt x-ray detectors
2012
Current-voltage (I-V) characteristics of Schottky Al/p-CdTe/Pt detectors were investigated in dark and at different temperatures. CdTe detectors with Al rectifying contacts, very appealing for high resolution x-ray and gamma ray spectroscopy, suffer from bias-induced polarization phenomena which cause current increasing with the time and severe worsening of the spectroscopic performance. In this work, we studied the time-dependence of the I-V characteristics of the detectors, both in reverse and forward bias, taking into account the polarization effects. The I-V measurements, performed at different time intervals between the application of the bias voltage and the measurement of the current…
Fenomeni di polarizzazione in rivelatori Al/CdTe/Pt per spettroscopia X e gamma
2014
L’uso dei rivelatori a semiconduttore ha avuto, negli anni, un’importanza strategica nella spettroscopia X e gamma (1 keV – 2 MeV), con eccellenti risultati sia in applicazioni mediche che astrofisiche. L’imaging medicale (mammografia, tomografia computerizzata), il monitoraggio ambientale (radiazione di fondo), rivelatori da piano focale per telescopi X in astrofisica e sistemi di fluorescenza a raggi X nei Beni Culturali ne rappresentano alcune importanti applicazioni. I rivelatori a semiconduttore hanno trovato largo impiego grazie alle loro interessanti proprietà soprattutto se confrontate con i sistemi di rivelazione tradizionali (a gas e scintillatori); un migliore rapporto segnale-ru…
Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications
2009
Over the last decade, cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector…
Crystal growth of functional materials by using CSVS and MOCVD:The AIIMnBVI and II-oxides case
2021
En esta tesis se presenta un estudio en profundidad del crecimiento cristalino y la caracterización de algunos materiales funcionales de la familia II-VI. Las propiedades estructurales, morfológicas, ópticas y eléctricas estudiadas se han correlacionado con la metodología y condiciones de crecimiento cristalino utilizadas. Entre la variedad de materiales II-VI, se han elegido 2 familias de semiconductores debido a sus propiedades singulares. El primero incluye los óxidos del grupo II, con elementos como el Zinc y el Cadmio, con una alta transparencia en el rango óptico visible. Estos compuestos se pueden usar en diversas aplicaciones en optoelectrónica, incluyendo su uso como óxidos conduct…