CdTe detectors responses to pulsed X-rays : comparison of different materials

1993 ◽  
Vol 302 ◽  
Author(s):  
L. Verger ◽  
M. Cuzin ◽  
F. Glasser ◽  
J. Lajzerowicz ◽  
F. Mathy ◽  
...  
Keyword(s):  
High Pressure ◽  
Dynamic Range ◽  
Transient Behavior ◽  
Bridgman Method ◽  
X Rays ◽  
Transient Responses ◽  
X Ray ◽  
Energy Beam ◽  
Photoconductive Detectors ◽  
Vertical Bridgman

ABSTRACTThe goal of this work is to compare and analyze the transient responses to X-ray pulses of different cadmium telluride detectors:- CdTe: Cl grown by the vertical Bridgman method (B.).- CdTe: Cl grown by the Travelling Heater Method (T.H.M.).- Cd0,8 Zn0,2 Te grown by the High Pressure Bridgman method (H.P.B.).Photoconductive detectors were subjected to very short (20 ns) 100 keV X-ray pulses and short (4 µs) 2 MeV pulses. The transient response of the photoconductors CdTe: Cl and CdZnTe under high X-ray energy beam were characterized in terms of sensitivity, linearity and dynamic range vs different parameters such as bias voltage and X-ray beam fluence. Bridgman and T.H.M. detectors show similar behaviors while H.P.B. detectors which are highly resistance show shorter transient behavior after the 20 ns pulses irradiations and larger afterglow after the 4 µs pulses irradiations.

Thermoelectric Properties of Pb1-xCdxSe Crystals Grown by Vertical Bridgman Method

2012 ◽  
Vol 194 ◽  
pp. 148-152
Author(s):  
Horng Jyh Gau ◽  
Yih Jye Chiou ◽  
Ching Cherng Wu ◽  
Yung Kang Kuo ◽  
Ching Hwa Ho
Keyword(s):  
Figure Of Merit ◽  
Carrier Transport ◽  
Sem Analysis ◽  
Bridgman Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vertical Bridgman Method ◽  
Temperature Dependences ◽  
Type Semiconductor ◽  
Vertical Bridgman

Single crystals of Pb1-xCdxSe compounds with x = 0, 0.01, 0.03, 0.05, 0.07 and 0.1 were grown by vertical Bridgman method. The crystalline phase and stochiometry for these crystals were investigated by X-ray diffraction, SEM and electron-probe microanalysis (EPMA). The thermoelectric behaviors for the Pb1-xCdxSe crystals were studied by means of thermal and carrier transport measurements in the temperature range between 50K and 400K. X-ray diffraction and SEM analysis confirmed that as-grown Pb1-xCdxSe crystals are simgle phase. The experimental results showed that the PbTe sample is p-type semiconductor but Pb1-xCdxSe samples with x = 0.01, 0.03, 0.05, 0.07 and 0.1 are n-type semiconductors. Temperature dependences of resistivity, Seebeck coefficient, and thermal conductivity for the various compositions of Pb1-xCdxSe were analyzed. The dimensionless thermoelectric figure of merit ZT for these compounds was evaluated and discussed. It was found that Pb0.95Cd0.05Se exhibits the best thermoelectric performance. The maximum figure of merit (ZT) of Pb0.95Cd0.05Se is about 0.47 at 290 K.

Crystal growth of CuInSe2 by the Bridgman method

1989 ◽  
Vol 67 (4) ◽  
pp. 294-297 ◽  
Author(s):  
W. S. Weng ◽  
L. S. Yip ◽  
I. Shih ◽  
C. H. Champness
Keyword(s):  
Crystal Growth ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Bridgman Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vertical Bridgman ◽  
Hall Effect Measurements ◽  
Rotation Technique ◽  
Crucible Rotation

Single crystals of CuInSe2 have been fabricated by the vertical Bridgman method. A conventional Czochralski crystal-pulling system was adapted for this purpose. An accelerated crucible-rotation technique was employed for a better mixing of the melt during the growth. Void- and crack-free crystal grains with an area as large as 50 mm2 and a thickness of more than 5 mm could be selectively cut from the ingots. From room-temperature Hall-effect measurements, mobility values as large as 73 cm2 ∙ V−1 ∙ s−1 were obtained for the present samples. X-ray diffraction studies suggested that abrasive polishing might create an amorphous layer on the surface of the CuInSe2 crystals.

Studies of local and intermediate range structure in crystalline and amorphous materials at high pressure using high-energy X-rays

2007 ◽  
Vol 22 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Lars Ehm ◽  
Sytle M. Antao ◽  
Jiuhua Chen ◽  
Darren R. Locke ◽  
F. Marc Michel ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Atomic Structure ◽  
Amorphous Materials ◽  
High Energy ◽  
Liquid Gallium ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Current State

The method of high-energy total elastic X-ray scattering to determine the atomic structure of nanocrystalline, highly disordered, and amorphous materials is presented. The current state of the technique, its potential, and limitations are discussed with two successful studies on the pressure induced phase transition in mackinawite (FeS) and the high-pressure behavior of liquid gallium.

The Hunt for Hydrogen in the High-Pressure Phase of Ca(OH)2 and Ca(OD)2: Neutrons Versus X-Rays

2004 ◽  
Vol 443-444 ◽  
pp. 341-344
Author(s):  
Robert J. Papoular ◽  
Martin Kunz
Keyword(s):  
High Pressure ◽  
High Pressure Phase ◽  
Recent Measurement ◽  
X Rays ◽  
Neutron Data ◽  
Neutron Measurement ◽  
X Ray ◽  
The Us ◽  
Deuterated Sample ◽  
Pressure Phase

A recent measurement on the high-pressure phase of Ca(OH)2using high-resolution synchrotron X-ray powder diffraction has been carried out on a hydrogenated sample at high-temperature. It complements an earlier time-of-flight neutron measurement carried out in the US on a deuterated sample at low temperature. The two protons are found by Rietveld refinement using a new suitable non-Fourier based strategy, for which GSAS and FullProf yield very similar results. Our X-ray result agrees with the previous neutron study for one proton site only, prompting us to reinvestigate the neutron data. A second new and distinct non Fourier-based strategy coupled with GSAS is used to tackle the latter data and indeed confirms the US results. Whilst the reasons for this X-Ray vs Neutron discrepancy can only be guessed at this stage, the use of the two related proton-finding strategies could be extended beyond our specific study.

scholarly journals Pixel detectors for diffraction-limited storage rings

2014 ◽  
Vol 21 (5) ◽  
pp. 1006-1010 ◽  
Author(s):  
Peter Denes ◽  
Bernd Schmitt
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Dynamic Range ◽  
State Of The Art ◽  
Storage Rings ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Pixel Detectors ◽  
Radiation Sources

Dramatic advances in synchrotron radiation sources produce ever-brighter beams of X-rays, but those advances can only be used if there is a corresponding improvement in X-ray detectors. With the advent of storage ring sources capable of being diffraction-limited (down to a certain wavelength), advances in detector speed, dynamic range and functionality is required. While many of these improvements in detector capabilities are being pursued now, the orders-of-magnitude increases in brightness of diffraction-limited storage ring sources will require challenging non-incremental advances in detectors. This article summarizes the current state of the art, developments underway worldwide, and challenges that diffraction-limited storage ring sources present for detectors.

scholarly journals Different modes of runaway electron beams generated in high-pressure gases

2021 ◽  
Vol 2064 (1) ◽  
pp. 012001
Author(s):  
V F Tarasenko ◽  
D A Sorokin ◽  
D V Beloplotov ◽  
M I Lomaev ◽  
E Kh Baksht ◽  
...  
Keyword(s):  
High Pressure ◽  
Runaway Electron ◽  
Experimental Studies ◽  
Beam Current ◽  
Current Amplitude ◽  
X Rays ◽  
X Ray ◽  
Beam Current Amplitude ◽  
The One ◽  
Direction Opposite

Abstract This article presents the results of experimental studies of different modes of a runaway electron beam (RAEB) generation in high-pressure gases as well as X-rays caused by it. In particular, the mode with the greatest beam current amplitude, the one with two current pulses, that with the X-ray pulse duration of 100s ns, the mode in which a RAEB propagates in the direction opposite from an anode, and some others are described. The effect of the cathode design and material on the RAEB current amplitude and duration in atmospheric-pressure air is shown. When analyzing the most common modes, the features of the gap breakdown are used.

scholarly journals High-Precision X-ray Total Scattering Measurements Using a High-Accuracy Detector System

2021 ◽  
Vol 7 (1) ◽  
pp. 2
Author(s):  
Kenichi Kato ◽  
Kazuya Shigeta
Keyword(s):  
High Precision ◽  
Dynamic Range ◽  
Atomic Displacement ◽  
High Accuracy ◽  
Detector System ◽  
Scattering Method ◽  
X Rays ◽  
Total Scattering ◽  
X Ray ◽  
Scattering Measurements

The total scattering method, which is based on measurements of both Bragg and diffuse scattering on an equal basis, has been still challenging even by means of synchrotron X-rays. This is because such measurements require a wide coverage in scattering vector Q, high Q resolution, and a wide dynamic range for X-ray detectors. There is a trade-off relationship between the coverage and resolution in Q, whereas the dynamic range is defined by differences in X-ray response between detector channels (X-ray response non-uniformity: XRNU). XRNU is one of the systematic errors for individual channels, while it appears to be a random error for different channels. In the present study, taking advantage of the randomness, the true sensitivity for each channel has been statistically estimated. Results indicate that the dynamic range of microstrip modules (MYTHEN, Dectris, Baden-Daettwil, Switzerland), which have been assembled for a total scattering measurement system (OHGI), has been successfully restored from 104 to 106. Furthermore, the correction algorithm has been optimized to increase time efficiencies. As a result, the correcting time has been reduced from half a day to half an hour, which enables on-demand correction for XRNU according to experimental settings. High-precision X-ray total scattering measurements, which has been achieved by a high-accuracy detector system, have demonstrated valence density studies from powder and PDF studies for atomic displacement parameters.

scholarly journals Zur Kenntnis von Ammoniumchrom(III)-fluorid NH4CrF4 / On Ammonium Chromium (III) Fluoride NH4CrF4

1979 ◽  
Vol 34 (7) ◽  
pp. 934-938 ◽  
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
X Rays ◽  
X Ray

Abstract The hitherto unreported compound NH4CrF4 could be prepared by applying hydrothermal high pressure techniques. X-ray powder data show NH4CrF4 to crystallize tetragonally with a = 743.2, c = 650.4 pm, similar to CsFeF4 and other TIAIF4-related structures. The magnetic behaviour was studied below room temperature and proved NH4CrF4 to become antiferromagnetic (TN = 34 K ) within the range known from other AICrF4 compounds. The thermolysis of NH4CrF4, as investigated by X-rays and TG/DTA, begins at about 400 °C and yields CrF3 and also Cr2F5, if extended to 1000 °C

Versatile Lithium Fluoride Luminescent Detectors for High Resolution Imaging Applications from Extreme Ultraviolet to Soft and Hard X-Rays

2016 ◽  
Vol 98 ◽  
pp. 54-63
Author(s):  
Francesca Bonfigli ◽  
Enrico Nichelatti ◽  
Maria Aurora Vincenti ◽  
Rosa Maria Montereali
Keyword(s):  
Spatial Resolution ◽  
Lithium Fluoride ◽  
Dynamic Range ◽  
High Spatial Resolution ◽  
Extreme Ultraviolet ◽  
Large Field ◽  
X Rays ◽  
X Ray ◽  
Research Fields ◽  
X Ray Imaging

X-ray imaging represents a very relevant tool in basic and applied research fields due to the possibility of performing non-destructive investigations with high spatial resolution. We present innovative X-ray imaging detectors based on visible photoluminescence from aggregate electronic defects locally created in lithium fluoride (LiF) during irradiation. Among the peculiarities of these detectors, noteworthy ones are their very high spatial resolution (intrinsic ∼2 nm, standard ∼300 nm) across a large field of view (>10 cm2), wide dynamic range (>103) and their insensitivity to ambient light. The material photoluminescence response can be enhanced through the proper choice of reflecting substrates and multi-layer designs in the case of LiF films. The present investigation deals with the most appealing X-ray imaging applications, from simple lensless imaging configurations with commonly-available laboratory polychromatic X-ray sources to X-ray imaging-dedicated synchrotron beamlines in absorption and phase contrast experiments.

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