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

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.

1997 ◽  
Vol 15 (1) ◽  
pp. 133-138 ◽  
Author(s):  
A.M. Buyko ◽  
O.M. Burenkov ◽  
V.K. Chernyshev ◽  
S.F. Garanin ◽  
S.D. Kuznetsov ◽  
...  

Powerful pulse installations are usually used to produce large yields of X-ray radiation. With an increase of the stored energy up to 100 MJ, the costof a single experiment on these installations becomes comparable to the cost of a shot with explosive magnetic generators (EMG), according to expert estimates. The physical scheme of a device with a changeable mass liner forlarge soft X-ray (in the range of 0.3 to 0.5 keV) yields eneration is investigated. The scheme investigated is substantially free from difficulties connected with high precision liners and fast switches for current pulse sharpening.


2020 ◽  
Vol 53 (3) ◽  
pp. 671-678 ◽  
Author(s):  
Satoshi Hiroi ◽  
Koji Ohara ◽  
Satoru Ohuchi ◽  
Yukihiro Umetani ◽  
Takashi Kozaki ◽  
...  

Total scattering measurements enable understanding of the structural disorder in crystalline materials by Fourier transformation of the total structure factor, S(Q), where Q is the magnitude of the scattering vector. In this work, the direct calculation of total scattering from a crystalline structural model is proposed. To calculate the total scattering intensity, a suitable Q-broadening function for the diffraction profile is needed because the intensity and the width depend on the optical parameters of the diffraction apparatus, such as the X-ray energy resolution and divergence, and the intrinsic parameters. X-ray total scattering measurements for CeO2 powder were performed at beamline BL04B2 of the SPring-8 synchrotron radiation facility in Japan for comparison with the calculated S(Q) under various optical conditions. The evaluated Q-broadening function was comparable to the full width at half-maximum of the Bragg peaks in the experimental total scattering pattern. The proposed calculation method correctly accounts for parameters with Q dependence such as the atomic form factor and resolution function, enables estimation of the total scattering factor, and facilitates determination of the reduced pair distribution function for both crystalline and amorphous materials.


2020 ◽  
Vol 10 (11) ◽  
pp. 2745-2753
Author(s):  
Jimin Cheon ◽  
Dongmyung Lee ◽  
Hojong Choi

An active pixel sensor (APS) in a digital X-ray detector is the dominant circuitry for a CMOS image sensor (CIS) despite its lower fill factor (FF) compared to that of a passive pixel sensor (PPS). Although the PPS provides higher FF, its overall signal-to-noise ratio (SNR) is lower than that of the APS. The required high resolution and small focal plane can be achieved by reducing the number of transistors and contacts per pixel. We proposed a novel passive pixel array and a high precision current amplifier to improve the dynamic range (DR) without minimizing the sensitivity for diagnostic compact digital X-ray detector applications. The PPS can be an alternative to improve the FF. However, size reduction of the feedback capacitor causes degradation of SNR performance. This paper proposes a novel PPS based on readout and amplification circuits with a high precision current amplifier to minimize performance degradation. The expected result was attained with a 0.35-μm CMOS process parameter with power supply voltage of 3.3 V. The proposed PPS has a saturation signal of 1.5 V, dynamic range of 63.5 dB, and total power consumption of 13.47 mW. Therefore, the proposed PPS readout circuit improves the dynamic range without sacrificing the sensitivity.


1986 ◽  
Vol 82 ◽  
Author(s):  
B. C. Larson ◽  
S. Iida ◽  
J. Z. Tischler ◽  
J. D. Lewis ◽  
G. E. Ice ◽  
...  

ABSTRACTLarge-angle diffuse scattering has been investigated for the purpose of studying coherent precipitates in a crystal lattice. Detailed calculations have been made of the scattering near Bragg reflections from cobalt precipitates in a copper host lattice. These calculations have been compared to x-ray diffuse scattering measurements made on aged (570°C for 17 hr.) Cu-0.95%Co crystals with x-rays of three different wavelengths at the NSLS. The results indicate that the size distribution, the concentration, and the internal strain of the precipitates can be determined from such diffuse scattering measurements.


2014 ◽  
Vol 21 (5) ◽  
pp. 1006-1010 ◽  
Author(s):  
Peter Denes ◽  
Bernd Schmitt

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.


2020 ◽  
Vol 22 (34) ◽  
pp. 18860-18867 ◽  
Author(s):  
Matthew E. Potter ◽  
Mark E. Light ◽  
Daniel J. M. Irving ◽  
Alice E. Oakley ◽  
Stephanie Chapman ◽  
...  

Novel in situ synchrotron total scattering measurements probe the assembly of primary building units into templated hierarchically porous aluminophosphate catalysts, providing unique insights to understanding crystallisation kinetics.


2019 ◽  
Vol 4 (2) ◽  
pp. 59 ◽  
Author(s):  
Alessandro Scordo
Keyword(s):  
X Rays ◽  

Since their discovery in 1895, the detection of X-rays has had a strong impact and various applications in several fields of science and human life [...]


2016 ◽  
Vol 98 ◽  
pp. 54-63
Author(s):  
Francesca Bonfigli ◽  
Enrico Nichelatti ◽  
Maria Aurora Vincenti ◽  
Rosa Maria Montereali

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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