A Spherically Bent Crystal X-Ray Spectrometer with Variable Curvature

1974 ◽  
pp. 521-530
Author(s):  
Donald L. Parker
Keyword(s):  
X Ray ◽  
Bent Crystal ◽  
Variable Curvature

A Spherically Bent Crystal X-Ray Specteometer with Variable Curvature

1973 ◽  
Vol 17 ◽  
pp. 521-530
Author(s):  
Donald L. Parker
Keyword(s):  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
High Signal ◽  
X Rays ◽  
X Ray ◽  
Bent Crystal ◽  
Variable Curvature ◽  
The Face ◽  
Low Levels ◽  
And Performance

AbstractThe design and performance of a spherically bent crystal x-ray spectrometer with variable curvature are given. A thin crystal with the diffracting planes parallel to the face is mounted on a vacuum chuck consisting of an O-ring in a brass mounting. A controlled partial vacuum is applied behind the crystal to cause spherical deformation of the lattice. Thus, rays from a point source on the focusing circle are diffracted to a line image also on the focusing circle. The differential pressure is automatically varied such that the source-to-crystal and crystal-to-image distances are equal and constant for all Bragg angles and hence the simple θ-2θ motion of a one flat crystal spectrometer is used.The data are accumulated by a scanning proportional counter tube placed behind a vertical slit (perpendicular to the scattering plane) located at the image line. The fixed chord length is 22 cm and the instrument is designed to scan from zero up to 120° 2θ. Crystals are easily interchanged and the automatic vacuum regulator has sufficient flexibility to allow tailoring the spherical bending to crystals of materials of various thicknesses. The resolution is easily adjusted by either the size of the x-ray source or the width of the detector slit. The performance of the spectrometer has been evaluated by characteristic x-rays produced by various samples placed in a demountable x-ray tube. The main advantages of this three-dimensional focusing instrument are the very high signal-to-noise ratio and the very low levels of x-ray flux required.

X-ray diffraction properties of curved crystal diffractors

1992 ◽  
Vol 50 (2) ◽  
pp. 1734-1735
Author(s):  
W. Z. Chang ◽  
D. B. Wittry
Keyword(s):  
Diffraction Theory ◽  
X Rays ◽  
Diffraction Image ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Bent Crystal ◽  
Diffraction Geometry ◽  
Crystal Parameter ◽  
Quantitative Procedure

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.

Bent Crystal X‐Ray Monochromators

1950 ◽  
Vol 21 (1) ◽  
pp. 102-102 ◽  
Author(s):  
B. E. Warren
Keyword(s):  
X Ray ◽  
Bent Crystal

scholarly journals Bent crystal x-ray mirrors for time-resolved experiments with femtosecond laser-produced x-ray pulses

2005 ◽  
Vol 21 ◽  
pp. 207-210 ◽  
Author(s):  
M Nicoul ◽  
U Shymanovich ◽  
S Kähle ◽  
T Caughey ◽  
D Sampat ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Time Resolved ◽  
X Ray ◽  
Bent Crystal

Characterization and on-line adjustment of the sagittal-bent Laue crystal profile

2018 ◽  
Vol 25 (5) ◽  
pp. 1346-1353
Author(s):  
Weiwei Dong ◽  
Quan Cai ◽  
Fugui Yang ◽  
Xu Liu ◽  
Jiaowang Yang ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Crystal Surface ◽  
Great Influence ◽  
High Energy ◽  
Double Crystal ◽  
X Ray ◽  
Bent Crystal ◽  
On Line ◽  
Condition Adjustment ◽  
Anticlastic Curvature

The sagittal-bent Laue monochromator can provide an ideal way to focus high-energy X-ray beams. However, the anticlastic curvature induced by sagittal bending has a great influence on the crystal performance. Thus, characterizing the bent-crystal shape is very important for predicting the performance of the bent-crystal monochromator. In this paper the crystal profile is measured by off-line optical metrology and on-line X-ray experiments. The off-line results showed that the bent-crystal surface could be well fitted to a saddle surface apart from a redundant cubic term which was related to the different couples applied on the crystal. On-line characterization of the meridional and the sagittal radius of the bent crystal includes double-crystal topography and ray-tracing measurement. In addition, the double-crystal topography experiment could be used as a quick diagnostic method for the bending condition adjustment. The sagittal radius of the bent crystal was characterized through a ray-tracing experiment by using a particularly designed tungsten mask. Moreover, rocking curves under different bending conditions were measured as well. The results were highly consistent with analytical results derived from the elastic theory. Furthermore, radii along different vertical positions under various bending conditions were measured and showed a quadratic relationship between the vertical positions and the meridional radii.

Large bent crystal vacuum x-ray spectrograph

Vacuum ◽  
1953 ◽  
Vol 3 (4) ◽  
pp. 459
Keyword(s):  
X Ray ◽  
Bent Crystal

Elliptically Bent Crystal Spectrometer for Z-Pinch Plasma X-Ray

2009 ◽  
Vol 36 (1) ◽  
pp. 115-118
Author(s):  
王洪建 Wang Hongjian ◽  
肖沙里 Xiao Shali ◽  
施军 Shi Jun ◽  
黄显宾 Huang Xianbin ◽  
杨礼兵 Yang Libing ◽  
...  
Keyword(s):  
Crystal Spectrometer ◽  
X Ray ◽  
Pinch Plasma ◽  
Bent Crystal ◽  
Z Pinch

Vacuum formed temporary spherically and toroidally bent crystal analyzers for x-ray absorption and x-ray emission spectroscopy

2019 ◽  
Vol 90 (1) ◽  
pp. 013106 ◽  
Author(s):  
Evan P. Jahrman ◽  
William M. Holden ◽  
Alexander S. Ditter ◽  
Stosh A. Kozimor ◽  
Scott L. Kihara ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
X Ray ◽  
Bent Crystal ◽  
X Ray Absorption

scholarly journals Improving the energy resolution of bent crystal X-ray spectrometers with position-sensitive detectors

2014 ◽  
Vol 21 (4) ◽  
pp. 762-767 ◽  
Author(s):  
Ari-Pekka Honkanen ◽  
Roberto Verbeni ◽  
Laura Simonelli ◽  
Marco Moretti Sala ◽  
Ali Al-Zein ◽  
...  
Keyword(s):  
High Resolution ◽  
Internal Stress ◽  
Photon Energy ◽  
Energy Resolution ◽  
Preceding Paper ◽  
X Ray ◽  
Bent Crystal ◽  
Position Sensitive ◽  
Position Sensitive Detectors ◽  
Bent Crystals

Wavelength-dispersive high-resolution X-ray spectrometers often employ elastically bent crystals for the wavelength analysis. In a preceding paper [Honkanenet al.(2014).J. Synchrotron Rad.21, 104–110] a theory for quantifying the internal stress of a macroscopically large spherically curved analyser crystal was presented. Here the theory is applied to compensate for the corresponding decrease of the energy resolution. The technique is demonstrated with a Johann-type spectrometer using a spherically bent Si(660) analyser in near-backscattering geometry, where an improvement in the energy resolution from 1.0 eV down to 0.5 eV at 9.7 keV incident photon energy was observed.

scholarly journals Diagnostic potential of advanced X-ray spectroscopy for investigation of hot dense plasmas

2004 ◽  
Vol 22 (1) ◽  
pp. 25-28 ◽  
Author(s):  
O. RENNER ◽  
I. USCHMANN ◽  
E. FÖRSTER
Keyword(s):  
Dense Plasma ◽  
X Ray ◽  
Dense Plasmas ◽  
Plasma Diagnosis ◽  
Bent Crystal ◽  
Complex Information ◽  
Diagnostic Potential ◽  
Vertical Dispersion ◽  
Fundamental Research

Modern experimental methods and instruments for X-ray spectral investigation of hot dense plasma provide complex information on environmental conditions in extreme states of matter. The basic spectroscopic conceptions for K-shell plasma diagnosis are outlined, the main characteristics of toroidally bent crystal spectrometers and vertical-dispersion instruments are briefly reviewed. Selected applications (monitoring and optimization of the emission from the femtosecond-laser-produced plasmas, characterization of colliding laser-exploded foils, spectral line merging, and continuum lowering in constrained-flow plasmas) demonstrate the usefulness of advanced spectroscopic methods for plasma diagnostics and fundamental research.

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