Bent Crystal X‐Ray Monochromators

1950 ◽  
Vol 21 (1) ◽  
pp. 102-102 ◽  
Author(s):  
B. E. Warren
Keyword(s):  
X Ray ◽  
Author(s):  
W. Z. Chang ◽  
D. B. Wittry

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.


2005 ◽  
Vol 21 ◽  
pp. 207-210 ◽  
Author(s):  
M Nicoul ◽  
U Shymanovich ◽  
S Kähle ◽  
T Caughey ◽  
D Sampat ◽  
...  

2018 ◽  
Vol 25 (5) ◽  
pp. 1346-1353
Author(s):  
Weiwei Dong ◽  
Quan Cai ◽  
Fugui Yang ◽  
Xu Liu ◽  
Jiaowang Yang ◽  
...  

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.


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 ◽  
...  

2019 ◽  
Vol 90 (1) ◽  
pp. 013106 ◽  
Author(s):  
Evan P. Jahrman ◽  
William M. Holden ◽  
Alexander S. Ditter ◽  
Stosh A. Kozimor ◽  
Scott L. Kihara ◽  
...  

2014 ◽  
Vol 21 (4) ◽  
pp. 762-767 ◽  
Author(s):  
Ari-Pekka Honkanen ◽  
Roberto Verbeni ◽  
Laura Simonelli ◽  
Marco Moretti Sala ◽  
Ali Al-Zein ◽  
...  

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.


2004 ◽  
Vol 22 (1) ◽  
pp. 25-28 ◽  
Author(s):  
O. RENNER ◽  
I. USCHMANN ◽  
E. FÖRSTER

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.


2015 ◽  
Vol 54 (16) ◽  
pp. 5147 ◽  
Author(s):  
Marius S. Schollmeier ◽  
Matthias Geissel ◽  
Jonathon E. Shores ◽  
Ian C. Smith ◽  
John L. Porter

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