scholarly journals New Slit System for Stationary Crystal and Film X‐Ray Topography Technique

1968 ◽  
Vol 39 (5) ◽  
pp. 774-775 ◽  
Author(s):  
A. Lindegaard Andersen
Keyword(s):  
X Ray ◽  
Slit System

Diffracted Beam Monochromators for Powder Diffractometry

1970 ◽  
Vol 14 ◽  
pp. 38-56
Author(s):  
E. M. Proctor ◽  
T. C. Furnas ◽  
W. F. Loranger
Keyword(s):  
Preferred Orientation ◽  
Signal To Noise ◽  
X Ray ◽  
Direct Beam ◽  
Vertical Divergence ◽  
Oriented Samples ◽  
Efficiency And Effectiveness ◽  
Slit System ◽  
Bent Crystals ◽  
Selection Of

AbstractThe efficiency and effectiveness of diffracted beam x-ray monochromators used in powder diffractometry have been described in so many ways that much confusion exists regarding their true performance. Although significant improvements in signal to noise ratios are readily achievable, and they offer a solution to the sample fluorescence problem, it is not without sacrifice to total intensity or achievable resolution or both. This paper discusses and describes a series of comparisons between filtered direct beam, LiF and graphite monochromators.These comparisons include the considerations necessary for the appropriate selection of diffracted beam slit system, the effect of vertical divergence as a function of two theta for singly bent crystals, the effects of a non-uniformity of contribution over the length of the crystal, and the geometry necessary for the singly bent and doubly bent crystals. The total intensity and the resolution of LiF and graphite are discussed, in particular, it is noted that the performance of monochromators with randomly oriented samples is quite different than their performance with samples showing preferred orientation or grain effects.A new diffracted beam monochromator based on the Rowland focusing geometry is described.

Quantitative characterization of the X-ray beam at the Australian Synchrotron Imaging and Medical Beamline (IMBL)

2017 ◽  
Vol 24 (1) ◽  
pp. 110-141 ◽  
Author(s):  
Andrew W. Stevenson ◽  
Jeffrey C. Crosbie ◽  
Christopher J. Hall ◽  
Daniel Häusermann ◽  
Jayde Livingstone ◽  
...  
Keyword(s):  
Detailed Knowledge ◽  
Quantitative Characterization ◽  
X Ray ◽  
Slit System ◽  
Synchrotron Imaging ◽  
Reliability And Robustness ◽  
Parameter Values ◽  
The Magnetic Field ◽  
Better Than

A critical early phase for any synchrotron beamline involves detailed testing, characterization and commissioning; this is especially true of a beamline as ambitious and complex as the Imaging & Medical Beamline (IMBL) at the Australian Synchrotron. IMBL staff and expert users have been performing precise experiments aimed at quantitative characterization of the primary polychromatic and monochromatic X-ray beams, with particular emphasis placed on the wiggler insertion devices (IDs), the primary-slit system and any in vacuo and ex vacuo filters. The findings from these studies will be described herein. These results will benefit IMBL and other users in the future, especially those for whom detailed knowledge of the X-ray beam spectrum (or `quality') and flux density is important. This information is critical for radiotherapy and radiobiology users, who ultimately need to know (to better than 5%) what X-ray dose or dose rate is being delivered to their samples. Various correction factors associated with ionization-chamber (IC) dosimetry have been accounted for, e.g. ion recombination, electron-loss effects. A new and innovative approach has been developed in this regard, which can provide confirmation of key parameter values such as the magnetic field in the wiggler and the effective thickness of key filters. IMBL commenced operation in December 2008 with an Advanced Photon Source (APS) wiggler as the (interim) ID. A superconducting multi-pole wiggler was installed and operational in January 2013. Results are obtained for both of these IDs and useful comparisons are made. A comprehensive model of the IMBL has been developed, embodied in a new computer program named spec.exe, which has been validated against a variety of experimental measurements. Having demonstrated the reliability and robustness of the model, it is then possible to use it in a practical and predictive manner. It is hoped that spec.exe will prove to be a useful resource for synchrotron science in general, and for hard X-ray beamlines, whether they are based on bending magnets or insertion devices, in particular. In due course, it is planned to make spec.exe freely available to other synchrotron scientists.

X‐Ray Slit System for Crystals with Small Angle Boundaries

1971 ◽  
Vol 42 (8) ◽  
pp. 1267-1268 ◽  
Author(s):  
C. Eubig ◽  
C. T. Tomizuka
Keyword(s):  
Small Angle ◽  
X Ray ◽  
Slit System

X-Ray examination of aramayoite

1926 ◽  
Vol 21 (115) ◽  
pp. 163-168 ◽  
Author(s):  
Kathleen Yardley
Keyword(s):  
Photographic Method ◽  
Circular Aperture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical Reflection ◽  
First Case ◽  
Slit System ◽  
Cleavage Face

An attempt was made to determine the true symmetry of the cleavage flakes of aramayoite by means of the Laue photographic method. Since X-ray diffraction takes place within the crystal, the lack of welldeveloped faces other than main cleavage faces was no disadvantage. One feature, however, which did prove a difficulty, was the pliability of thin clevage flakes referred to by Dr. Spencer. It was essential that the whole of the main cleavage face upon which the X-ray beam was incident should be strictly perpendicular to that beam. In order to ensure this, only those flakes were used which gave a single optical reflection, and two distinct methods of setting were resorted to. In the first case the slit (circular aperture) was used vertically ; the flat end of the slit system was ground truly perpendicular to the slit itself and was thus horizontal.

A satellite-borne X-ray spectroheliograph

1971 ◽  
Vol 321 (1547) ◽  
pp. 493-502 ◽  
Keyword(s):  
Temporal Variation ◽  
Pulse Height ◽  
Grazing Incidence ◽  
Spatial And Temporal Variation ◽  
X Ray ◽  
Proportional Counters ◽  
Slit System ◽  
Wavelength Discrimination

A grazing incidence X-ray telescope for the study of the spatial and temporal variation of solar X-radiation in the region 0.8 to 1.6 nm, with proportional counters and pulse height wavelength discrimination, is described in some detail. An accompanying slit system covering the 0.3 to 0.9 nm region provides a more rapid coverage of flares than the spacecraft raster period would otherwise allow. Results are given illustrating the types of data being received from this instrument, which has been operating correctly for 18 months.

scholarly journals Pyrolitic Graphite Mosaic Crystal Thickness and Mosaicity Optimization for an Extended Source Von Hamos X-ray Spectrometer

2019 ◽  
Vol 4 (2) ◽  
pp. 38 ◽  
Author(s):  
Alessandro Scordo ◽  
Catalina Curceanu ◽  
Marco Miliucci ◽  
Florin Sirghi ◽  
Johann Zmeskal
Keyword(s):  
High Energy ◽  
High Energy Resolution ◽  
Crystal Thickness ◽  
Special Role ◽  
Extended Source ◽  
X Ray ◽  
Peak Resolution ◽  
Slit System ◽  
Bragg Spectroscopy ◽  
Effective Source

Bragg spectroscopy, one of the best established experimental techniques for high energy resolution X-ray measurements, has always been limited to the measurement of photons produced from well collimated (tens of microns) or point-like sources; recently, the VOXES collaboration at INFN National Laboratories of Frascati developed a prototype of a high resolution and high precision X-ray spectrometer working also with extended isotropic sources. The realized spectrometer makes use of Highly Annealed Pyrolitic Graphite (HAPG) crystals in a “semi”-Von Hamos configuration, in which the position detector is rotated with respect to the standard Von Hamos one, to increase the dynamic energy range, and shows energy resolutions at the level of 0.1% for photon energies up to 10 keV and effective source sizes in the range 400–1200 μ m in the dispersive plane. Such wide effective source dimensions are achieved using a double slit system to produce a virtual point-like source between the emitting target and the crystal. The spectrometer performances in terms of reflection efficiency and peak resolution depend on several parameters, among which a special role is played by the crystal mosaicity and thickness. In this work, we report the measurements of the Cu(K α 1 , 2 ) and the Fe(K α 1 , 2 ) lines performed with different mosaicity and thickness crystals in order to investigate the influence of the parameters on the peak resolution and on the reflection efficiency mentioned above.

X-ray intensity patterns from finite perfect crystals

1999 ◽  
Vol 55 (6) ◽  
pp. 1000-1013
Author(s):  
Gunnar Thorkildsen ◽  
Helge B. Larsen
Keyword(s):  
Theoretical Study ◽  
Plane Waves ◽  
X Ray ◽  
Characteristic Lines ◽  
Different Types ◽  
Infinite Crystal ◽  
Lateral Crystal ◽  
Slit System ◽  
Green Technique ◽  
The Waves

A theoretical study dealing with intensity interference patterns from the exit surfaces of finite perfect t\times l crystals has been undertaken using the Takagi–Taupin equations and the Riemann–Green technique. Numerical simulations have been performed for the 220 reflection in diamond allowing for different types of amplitude-modulated incoming plane waves. The effects caused by limiting the waves by a slit system are also discussed. The results show strong influence of the lateral crystal boundaries and are closely related to the geometrical region structures formed by the characteristic lines associated with the equations. In the limit of a semi-infinite crystal, the Borrmann–Lehmann interference patterns are retrieved.

scholarly journals Implementation of a crossed-slit system for fast alignment of sealed polycapillary X-ray optics

2020 ◽  
Vol 27 (6) ◽  
pp. 1730-1733
Author(s):  
Anna Zymaková ◽  
Krishna Khakurel ◽  
Alessandra Picchiotti ◽  
Wojciech Błachucki ◽  
Jakub Szlachetko ◽  
...  
Keyword(s):  
X Rays ◽  
Acceptance Angle ◽  
Ray Optics ◽  
X Ray ◽  
Starting Point ◽  
User Facility ◽  
3D Printed ◽  
Good Starting Point ◽  
Slit System ◽  
Jet Plasma

A new modification of a table-top laser-driven water-jet plasma X-ray source has been successfully implemented and commissioned at the Extreme Light Infrastructure (ELI) Beamlines user facility. In order to preserve the broadband nature of the source for spectroscopic experiments, a polycapillary lens was initially chosen as the focusing element. Generally, polycapillary X-ray optics have a narrow photon acceptance angle and small field of view, making alignment complicated and time-consuming. This contribution demonstrates a straightforward, reliable and reproducible procedure for aligning polycapillary focusing optics with broadband X-rays. The method involves a pre-alignment step where two X-ray slits are mounted orthogonally on opposite sides of a 3D-printed cylindrical polycapillary holder. This helps to precisely determine the optical axis of the X-ray beam. Subsequent mounting of the polycapillary in the pre-aligned holder with the slits removed allowed for immediate transmission of the X-ray photons through the optics and has provided a good starting point for fine alignment.

Rapid Recording of Powder Diffraction Patterns With Si(Li) X-Ray Energy Analysis System: W and Cu Targets and Error Analysis

1971 ◽  
Vol 15 ◽  
pp. 240-253 ◽  
Author(s):  
Cullie J. Sparks
Keyword(s):  
Energy Analysis ◽  
Energy Calibration ◽  
X Ray Diffraction ◽  
Recording Time ◽  
X Ray ◽  
Characteristic Lines ◽  
Slit System ◽  
Diffraction Peaks ◽  
Diffraction Patterns ◽  
Analysis System

X-ray diffraction patterns using continuous radiation from copper and tungsten target x-ray tubes and detected with a Si(Li) energy analysis system are presented. Errors caused by a misaligned diffractometer and x-ray penetration into the sample are shown to be more difficult to correct and larger in magnitude than errors arising from energy calibration. All these errors can be minimized by mixing a standard with the unknown sample.The energy resolution of the detector influences the breadth of the diffraction peaks more strongly than the standard slit systems available with commercial diffractometers. Thus, to reduce the recording time and maintain the same standard deviation for the data, one should increase the sizes of the front and receiving slits including the Soller slits. X-ray energy diffraction patterns can be recorded with standard deviations less than +0.001 Å in the d spacing with only 200 sec measurement time using the standard diffractometer slit system. Copper targets are probably as useful as tungsten even though the continuous intensity is about three times.less. Copper has fewer interfering characteristic lines, and its use permits convenient conversion to normal θ scanning diffractometer operation.

A New Absolute-Scale Small-Angle X-Ray Scattering Instrument

1969 ◽  
Vol 13 ◽  
pp. 618-631
Author(s):  
H. Pessen ◽  
T. F. Kumosinski ◽  
S. N. Timasheff ◽  
R. R. Calhoun ◽  
J. A. Connelly
Keyword(s):  
Small Angle ◽  
Mechanical Stability ◽  
Horizontal Tube ◽  
X Ray ◽  
X Ray Scattering ◽  
Fine Focus ◽  
Slit System ◽  
Ease Of Access ◽  
Surface Plate ◽  
Ray Scattering

A small-angle X-ray scattering apparatus is described which is based on a Guinier focusing arrangement, utilizing a fine-focus tube, a Johann-type curved-crystal monochromator, two goniometermounted beam-defining slits and proportional detection. It differs from previously described instruments in important respects. Using a horizontal goniometer, it affords ease of access and mechanical stability to mounted parts, such as slits and beam stop. The major instrument assemblies--the horizontal tube housing producing the vertical line-shaped beam, and the goniometer table--are mounted on a granite surface plate for stability. For ease, precision and reproducibility in alignment, fine adjustments, with micrometer heads or dial indicators where advisable, are provided for all pertinent rotational and translational motions of the various subassemblies. In particular, provision is made for fine adjustment of the goniometer as a whole with respect to the X-ray source, to facilitate threading the monochromator-focused beam through the slit system and the center of rotation of the detector arm.

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