POSITION-SENSITIVE X-RAY DETECTOR SYSTEM FOR HIGH RESOLUTION PIXE MEASUREMENTS

1992 ◽  
Vol 02 (03) ◽  
pp. 263-268 ◽  
Author(s):  
H. Hamanaka ◽  
K. Hasegawa ◽  
Y. Yamamoto
Keyword(s):  
High Resolution ◽  
Delay Line ◽  
Detection Efficiency ◽  
X Rays ◽  
Good Position ◽  
X Ray ◽  
Sensitivity Distribution ◽  
Order Of Magnitude ◽  
New Type ◽  
Position Sensitive

A position-sensitive proportional counter with a carbon fiber anode, a goniometer and its associated electronics have been constructed to measure particle induced X-rays. The counter is easy to construct and its volume is about one order of magnitude smaller than a commercially available delay-line PSPC. This counter has good position linearity and uniform sensitivity distribution. Comparison is made between the new type of PSPC and an older one previously reported. It is shown that an enlargement of the X-ray window of the PSPC is effective for improving the detection efficiency.

A new high-resolution small-angle X-ray scattering apparatus using a fine-focus rotating anode, point-focusing collimation and a position-sensitive proportional counter

1984 ◽  
Vol 17 (5) ◽  
pp. 337-343 ◽  
Author(s):  
O. Yoda
Keyword(s):  
High Resolution ◽  
Small Angle ◽  
Proportional Counter ◽  
Anisotropic Scattering ◽  
Photon Flux ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Position Sensitive ◽  
Ray Scattering

A high-resolution small-angle X-ray scattering camera has been built, which has the following features. (i) The point collimation optics employed allows the scattering cross section of the sample to be directly measured without corrections for desmearing. (ii) A small-angle resolution better than 0.5 mrad is achieved with a camera length of 1.6 m. (iii) A high photon flux of 0.9 photons μs−1 is obtained on the sample with the rotating-anode X-ray generator operated at 40 kV–30 mA. (iv) Incident X-rays are monochromated by a bent quartz crystal, which makes the determination of the incident X-ray intensity simple and unambiguous. (v) By rotation of the position-sensitive proportional counter around the direct beam, anisotropic scattering patterns can be observed without adjusting the sample. Details of the design and performance are presented with some applications.

A high-resolution X-ray diffractometer for the study of imperfect materials

2002 ◽  
Vol 35 (5) ◽  
pp. 606-614 ◽  
Author(s):  
A. Boulle ◽  
O. Masson ◽  
R. Guinebretière ◽  
A. Lecomte ◽  
A. Dauger
Keyword(s):  
High Resolution ◽  
Optical Element ◽  
Strong Increase ◽  
Rocking Curve ◽  
One Dimensional ◽  
X Ray ◽  
Rapid Acquisition ◽  
Order Of Magnitude ◽  
Position Sensitive ◽  
The One

A high-resolution X-ray diffractometer devoted to the study of imperfect materials (mainly oxides and ceramics) is presented. It is based on a rotating anode generator, a four-bounce monochromator, a five-movement sample holder and a curved position-sensitive detector (PSD). This setup allows rapid acquisition of a reciprocal-space map (in less than 10 h) even for very poorly diffracting materials. The two-dimensional instrumental profile is calculated taking into account each optical element in the beam path. The one-dimensional instrumental profiles corresponding to widely used scans (ω scan, θ–2θ scan, rocking curve and powder scan) are also calculated. In the three former cases, the setup exhibits an excellent angular resolution (0.003°), whereas in the latter case the resolution is lowered by one order of magnitude at the benefit of a strong increase in the collected intensity. The possibilities of this diffractometer are illustrated with three examples: an epitaxic layer, a microstructured single crystal and a powder.

Simulation of a Gas Electron Multiplier Detector for Hard X-Ray Imaging with a Novel Nano Converter

2013 ◽  
Vol 829 ◽  
pp. 227-230 ◽  
Author(s):  
Elham Edalatkhah ◽  
Shahyar Saramad ◽  
Shahab Sheibani
Keyword(s):  
Medical Imaging ◽  
Detection Efficiency ◽  
Electron Multiplier ◽  
Gas Electron Multiplier ◽  
X Ray ◽  
X Ray Imaging ◽  
Gas Detector ◽  
Order Of Magnitude ◽  
Position Sensitive ◽  
Simulation Results

One of the most marvelous applications of GEM is hard X-ray imaging. For increasing the detection efficiency, a photoconverter is usually required. In this work a novel nanostructure photo converter is proposed. Simulation results show that the combination of fast position sensitive gas detector with nanophoto converter can be improved the detection efficiency by one order of magnitude in comparison to the bulk one, which is more benefic for hard X-ray medical imaging applications.

One-Dimensional, Curved, Position-Sensitive Detector for X-Ray Diffractometry

1982 ◽  
Vol 26 ◽  
pp. 269-274 ◽  
Author(s):  
B. Sleaford ◽  
V. Perez-Mendez ◽  
C.N.J. Wagner
Keyword(s):  
Delay Line ◽  
Position Sensitive Detector ◽  
Gas Mixture ◽  
X Rays ◽  
Angular Range ◽  
Sensitive Detector ◽  
Crystalline Materials ◽  
One Dimensional ◽  
X Ray ◽  
Position Sensitive

AbstractA curved, one-dimensional position-sensitive detector has been designed and constructed for the measurement of the scattering patterns from non-crystalline materials. The chamber is a one-dimensional, pressurized, gas-filled detector with delay line readout for position encoding. It covers an angular range of 45° in 2θ, and its quantum efficiency is 80% and 50% for 17.5 and 60 KeV x-rays, respectively, when using a Xe-20%CO2 gas mixture at 7 atm.

Cryogenic high-resolution X-ray spectrometers for SR-XRF and microanalysis

1998 ◽  
Vol 5 (3) ◽  
pp. 515-517 ◽  
Author(s):  
M. Frank ◽  
C. A. Mears ◽  
S. E. Labov ◽  
L. J. Hiller ◽  
J. B. le Grand ◽  
...  
Keyword(s):  
High Resolution ◽  
Energy Resolution ◽  
Superconducting Tunnel Junction ◽  
Semiconductor Detectors ◽  
X Rays ◽  
X Ray ◽  
Sr Xrf ◽  
Demonstration Experiment ◽  
Near Future ◽  
Stj Detector

Experimental results are presented obtained with a cryogenically cooled high-resolution X-ray spectrometer based on a 141 × 141 µm Nb-Al-Al2O3-Al-Nb superconducting tunnel junction (STJ) detector in an SR-XRF demonstration experiment. STJ detectors can operate at count rates approaching those of semiconductor detectors while still providing a significantly better energy resolution for soft X-rays. By measuring fluorescence X-rays from samples containing transition metals and low-Z elements, an FWHM energy resolution of 6–15 eV for X-rays in the energy range 180–1100 eV has been obtained. The results show that, in the near future, STJ detectors may prove very useful in XRF and microanalysis applications.

Applications of High-Resolution Powder X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 7-14 ◽  
Author(s):  
Andrew N. Fitch
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Structural Characterisation ◽  
Pdf Analysis

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.

HIGH-RESOLUTION PIXE USING BRAGG’S SPECTROMETER

1991 ◽  
Vol 01 (03) ◽  
pp. 251-258 ◽  
Author(s):  
M. TERASAWA
Keyword(s):  
High Resolution ◽  
Heavy Ions ◽  
X Rays ◽  
Light Elements ◽  
Element Analysis ◽  
X Ray ◽  
Peak Intensity ◽  
Moderate Energy ◽  
Practical Analysis ◽  
Wavelength Selectivity

K, L, and M X-rays in the wavelengths between 6Å and 130Å generated by the bombardment of 200 keV protons and other heavy ions were measured by means of a wavelength dispersive Bragg’s spectrometer. The X-ray peak intensity was fairly high in general, while the background was very low. The technique was favorably applied to a practical analysis of several light elements (Be, B, C, N, O, and F). Use of moderate-energy heavy ions considering the wavelength selectivity in X-ray generation was effective for the element analysis. The high-resolution spectrometry in the analytical application of ion-induced X-ray generation was found to be useful for the study of fine electronic structure, e.g. satellite and hypersatellite X-ray study, and of the chemical state of materials.

scholarly journals Micrometer-resolution imaging using MÖNCH: towards G2-less grating interferometry

2016 ◽  
Vol 23 (6) ◽  
pp. 1462-1473 ◽  
Author(s):  
Sebastian Cartier ◽  
Matias Kagias ◽  
Anna Bergamaschi ◽  
Zhentian Wang ◽  
Roberto Dinapoli ◽  
...  
Keyword(s):  
High Resolution ◽  
Silicon Detector ◽  
Limiting Factor ◽  
X Rays ◽  
X Ray ◽  
Charge Cloud ◽  
High Resolution Images ◽  
Resolution Imaging ◽  
Hybrid Silicon ◽  
Small Pixel

MÖNCH is a 25 µm-pitch charge-integrating detector aimed at exploring the limits of current hybrid silicon detector technology. The small pixel size makes it ideal for high-resolution imaging. With an electronic noise of about 110 eV r.m.s., it opens new perspectives for many synchrotron applications where currently the detector is the limiting factor,e.g.inelastic X-ray scattering, Laue diffraction and soft X-ray or high-resolution color imaging. Due to the small pixel pitch, the charge cloud generated by absorbed X-rays is shared between neighboring pixels for most of the photons. Therefore, at low photon fluxes, interpolation algorithms can be applied to determine the absorption position of each photon with a resolution of the order of 1 µm. In this work, the characterization results of one of the MÖNCH prototypes are presented under low-flux conditions. A custom interpolation algorithm is described and applied to the data to obtain high-resolution images. Images obtained in grating interferometry experiments without the use of the absorption grating G2are shown and discussed. Perspectives for the future developments of the MÖNCH detector are also presented.

scholarly journals Synchrotron and Laboratory Studies Utilizing a New Powder Diffraction Technique

1992 ◽  
Vol 36 ◽  
pp. 653-661 ◽  
Author(s):  
G. S. Knapp ◽  
M. A. Beno ◽  
G. Jennings ◽  
M. Engbretson ◽  
M. Ramanathan
Keyword(s):  
Powder Diffraction ◽  
Sample Surface ◽  
X Rays ◽  
High Count ◽  
Synchrotron Source ◽  
Bent Crystal ◽  
Capillary Sample ◽  
Order Of Magnitude ◽  
New Type ◽  
Large Improvement

AbstractWe have developed a new type of powder diffractometer. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument can achieve an order of magnitude improvement in count rate over existing methods with proper optics. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3° to 4° instead of one angle at a time thereby providing a large improvement over conventional diffractometers.

scholarly journals The Effect of Image Resolution on Automated Classification of Chest X-rays

2021 ◽  
Author(s):  
Md Inzamam Ul Haque ◽  
Abhishek K Dubey ◽  
Jacob D Hinkle
Keyword(s):  
High Resolution ◽  
Automated Analysis ◽  
Image Resolution ◽  
Free Text ◽  
X Rays ◽  
Training Time ◽  
X Ray ◽  
Radiology Reports ◽  
Chest X Ray ◽  
High Resolution Images

Deep learning models have received much attention lately for their ability to achieve expert-level performance on the accurate automated analysis of chest X-rays. Although publicly available chest X-ray datasets include high resolution images, most models are trained on reduced size images due to limitations on GPU memory and training time. As compute capability continues to advance, it will become feasible to train large convolutional neural networks on high-resolution images. This study is based on the publicly available MIMIC-CXR-JPG dataset, comprising 377,110 high resolution chest X-ray images, and provided with 14 labels to the corresponding free-text radiology reports. We find, interestingly, that tasks that require a large receptive field are better suited to downscaled input images, and we verify this qualitatively by inspecting effective receptive fields and class activation maps of trained models. Finally, we show that stacking an ensemble across resolutions outperforms each individual learner at all input resolutions while providing interpretable scale weights, suggesting that multi-scale features are crucially important to information extraction from high-resolution chest X-rays.

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