scholarly journals Characterization of Chromium Compensated GaAs Sensors with the Charge-Integrating JUNGFRAU Readout Chip by Means of a Highly Collimated Pencil Beam

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1550
Author(s):  
Dominic Greiffenberg ◽  
Marie Andrä ◽  
Rebecca Barten ◽  
Anna Bergamaschi ◽  
Martin Brückner ◽  
...  

Chromium compensated GaAs or GaAs:Cr sensors provided by the Tomsk State University (Russia) were characterized using the low noise, charge integrating readout chip JUNGFRAU with a pixel pitch of 75 × 75 µm2 regarding its application as an X-ray detector at synchrotrons sources or FELs. Sensor properties such as dark current, resistivity, noise performance, spectral resolution capability and charge transport properties were measured and compared with results from a previous batch of GaAs:Cr sensors which were produced from wafers obtained from a different supplier. The properties of the sample from the later batch of sensors from 2017 show a resistivity of 1.69 × 109 Ω/cm, which is 47% higher compared to the previous batch from 2016. Moreover, its noise performance is 14% lower with a value of (101.65 ± 0.04) e− ENC and the resolution of a monochromatic 60 keV photo peak is significantly improved by 38% to a FWHM of 4.3%. Likely, this is due to improvements in charge collection, lower noise, and more homogeneous effective pixel size. In a previous work, a hole lifetime of 1.4 ns for GaAs:Cr sensors was determined for the sensors of the 2016 sensor batch, explaining the so-called “crater effect” which describes the occurrence of negative signals in the pixels around a pixel with a photon hit due to the missing hole contribution to the overall signal causing an incomplete signal induction. In this publication, the “crater effect” is further elaborated by measuring GaAs:Cr sensors using the sensors from 2017. The hole lifetime of these sensors was 2.5 ns. A focused photon beam was used to illuminate well defined positions along the pixels in order to corroborate the findings from the previous work and to further characterize the consequences of the “crater effect” on the detector operation.

2014 ◽  
Vol 21 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Jan Wernecke ◽  
Christian Gollwitzer ◽  
Peter Müller ◽  
Michael Krumrey

A dedicated in-vacuum X-ray detector based on the hybrid pixel PILATUS 1M detector has been installed at the four-crystal monochromator beamline of the PTB at the electron storage ring BESSY II in Berlin, Germany. Owing to its windowless operation, the detector can be used in the entire photon energy range of the beamline from 10 keV down to 1.75 keV for small-angle X-ray scattering (SAXS) experiments and anomalous SAXS at absorption edges of light elements. The radiometric and geometric properties of the detector such as quantum efficiency, pixel pitch and module alignment have been determined with low uncertainties. The first grazing-incidence SAXS results demonstrate the superior resolution in momentum transfer achievable at low photon energies.


2021 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Lalu A. Didik ◽  
Muh. Wahyudi

The synthesis of CuCrO2 crystals by mixing CuO and Cr2O3 has been carried out using the solid reaction method at a temperature of 1200 0C. The characterization of the structure used XRD and analyzed using GSAS software. The results of characterization using XRD showed that no other phase occurred. This is evidenced by the absence of other phases from the results of refinement of measurement data with reference data and a value of χ 2 which is 1.222. The lattice parameter values resulting from the refinement of the CuCrO2 X-ray diffraction pattern are a = b = 2.9715 Å and c = 17.1104 Å with a cell volume of 130.584 Å 3. In addition to the lattice parameter values, the distance between atoms was also obtained, both Cu - O, Cr - Cr, and Cr - O.


1993 ◽  
Vol 37 ◽  
pp. 145-151
Author(s):  
N. Loxley ◽  
S. Cockerton ◽  
B. K. Tanner

AbstractWe show that a very low noise, high dynamic range scintillation detector has major advantages over conventional detectors for characterization of pseudomorphic HEMT structures by high resolution X-ray diffraction. We show that the reduced background enables a second modulation period to be detected, enabling the thickness and composition to be determined independently. Using a conventional X-ray generator and diffractometer we demonstrate that, in a single scan taking only 10 seconds, we are able to obtain sufficiently good data to provide quality assurance.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Rodrigo Heleno Alves ◽  
Thais Vitória da Silva Reis ◽  
Suzimara Rovani ◽  
Denise Alves Fungaro

In this study, ash from sugarcane waste was used in the synthesis of biosilica using alkaline extraction followed by acid precipitation. Different parameters that could influence the silica particle synthesis were evaluated. The ash and synthesized biosilica were characterized by a combination of spectroscopic and chemical techniques such as XRD, XRF, SEM, particle size analyser, N2 adsorption analysis, TGA, and FTIR. The best condition for biosilica production was achieved with fusion method and aging temperature of 80°C for 1 h during gel formation. X-ray powder diffraction pattern confirms the amorphous nature of synthesized silica. The purity of the prepared silica was 99% silica which was confirmed by means of XRF. The experimental data suggest that the sugarcane waste ash could be converted into a value-added product, minimizing the environmental impact of disposal problems.


Author(s):  
S. L. Hill ◽  
K. Krishnan ◽  
J. R. Ferraro

Certain classes of organic charge-transfer salts demonstrate superconducting behavior at liquid helium temperatures. Single crystal x-ray diffraction and infrared microreflectance analysis have been performed on several conducting systems to associate the nature of the crystalline structure with the electrical conductivity. The infrared spectrum for a single crystal salt exhibits absorptions which correlate with superconducting behavior.Discussion Williams and coworkers have performed x-ray Crystallography experiments to demonstrate the presence of an anion cavity between radical cation stacks- of bis(ethylenedithio)- tetrathiafulvalene (ET). The sulfur…sulfur interstack distance in a beta or kappa phase salt assumes a value less than the Vanderwaals distance and exhibit a superconducting (two dimensional) metal behavior (verified by Fermi surface calculations) at 1-20K. The structures of alpha and beta phase ET2I3 suggest the potential for several potential intermolecular interaction modes. It may be observed that the beta phase permits both interstack as well as H … X anionic interactions, whereas these interactions are less likely to occur in the alpha phase.


2014 ◽  
Vol 893 ◽  
pp. 69-74
Author(s):  
Johar Banjuraizah ◽  
Mohd. Haziq Che Ani ◽  
A.R. Mohamed

Transition metal oxide-doped CCTO (CaCu3Ti4O12) ceramics were prepared by a conventional solgel synthesis method and the effects of pure CCTO and CCTO doped with Mn, Fe, Co, Ni to the crystal structure, microstructures and dielectrical properties of samples were investigated. The phase composition and microstructure were studied by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis reveals that all samples exhibited multiphases with the pseudo-perovskite cubic CCTO phase with space group Im-3 as the main phase in undoped and doped CCTO samples. Peaks of monoclinic CuO and peroveskite CaTiO3 could also be seen in all samples which indicate that solid solution of CuO in CaTiO3 lattice was incomplete.SEM results show that doping effectively enhanced densification. SEM micrographs also suggested that the morphologies of doped CCTO ceramics had showed a matrix consisting of large grains wherein the small grains were embedded between the larger grains. Dielectric properties of pure and doped CCTO were investigated in a broad frequency range of the dielectric constant reached a value as high as εr = 29.4 at room temperature for CCTO doped with Ni at frequency (1000 Hz). Besides the sintering conditions, the microstructure and the dielectric properties of the CCTO are strongly influenced by type of doping elements.


2021 ◽  
pp. 3858-3870
Author(s):  
M. F. A. Alias ◽  
H. A. Abdulrahman

In this work, a (CdO)0.94:(In2O3)0.06 film was developed on a glass substrate using Q- switching pulse laser beam (Nd:YAG; wavelength 1064 nm). The quantitative elemental analysis of the (CdO)0.94:(In2O3)0.06 thin film was achieved using energy dispersive X- ray diffraction (EDX). The topological and morphological properties of the deposited thin film were investigated using atomic force microscope (AFM) and field emission scan electron microscopy (FESEM). The I-V characteristic and Hall effect of (CdO)0.94 :(In2O3)0.06 thin films were used  to  study the electrical properties. The gas sensor properties of the film prepared on n-Si were investigated for oxidization and reduction gases.


Molekul ◽  
2010 ◽  
Vol 5 (2) ◽  
pp. 105 ◽  
Author(s):  
Bilalodin Bilalodin

Study on magnetic properties of iron sand on the Logending beach sand has been done. The research aims to identify the mineral content and characterization of magnetic properties on the Logending beach sand. The irond sand samples taken from the Logending beach with several lokation. Sand then dried, determined density and magnetic content is separated using a permanen magnet. The iron sand were analyzed using XRD ( X-ray difraction) and characterization of magnetic properties using the VSM (Vibrating sample magnetometer). The research shows that minerals are contained hematit (Fe2O3), with a value of susceptibility is 0.43 x10-6 m3/kg. The main magnetic mineral of iron sand from logending beach is paramagnetic.


2011 ◽  
Vol 691 ◽  
pp. 15-22
Author(s):  
Rosalba Esquivel ◽  
Miguel A. Suárez ◽  
Juan.A. Alcántara ◽  
J. Federico Chávez

The microstructural changes of six Al-Cu-Fe alloys; A)Al62Cu25.5Fe12.5, B) Al65Cu20Fe15, C)Al68Cu20Fe12, D)Al61Cu26Fe13, E) Al65Cu22.5Fe12.5, F)Al64Cu25.5Fe13.5, where the icosahedral phase is present, have been experimentally studied in both as-cast and annealed conditions by X-ray diffractometry, optical metallography, scanning electron microscopy and hardness tests. The resulting microstructures were characterized to investigate the effect of chemical composition on percentage of icosahedral phase and the changes in hardness obtained in this composition range. It was found that the B) Al65Cu20Fe15alloy showed the microstructure with major amount of icosahedral phase in as-cast condition with a value of 50 area%, while the A) alloy showed the highest amount of icosahedral phase. The hardness of phases after heat treatment increased with respect to alloys in as-cast condition, the hardness of y-Al65Cu20Fe15phase increased between 20-25%, while the l-Al13Fe4 phase increased 9%.


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