Comparison of monochromators with a bent parabolic mirror and a varied-spacing grating for the 2.0 GeV high-brilliance synchrotron radiation source (VSX)

1998 ◽  
Vol 5 (3) ◽  
pp. 817-819
Author(s):  
K. Mashima ◽  
N. Kihara ◽  
E. Ishiguro

A design study of monochromators for a 2.0 GeV electron/positron storage ring for high-brilliance synchrotron radiation in the vacuum ultraviolet (VUV) and the soft X-ray regions is described. Two types of VUV/soft X-ray grazing-incidence monochromators, one with a bent parabolic mirror and the other with a varied-spacing grating, are designed. Without any slope error, the expected resolving power of the former is much higher, but the latter is less affected by slope errors of the optical elements.

2011 ◽  
Vol 19 (1) ◽  
pp. 30-38 ◽  
Author(s):  
O. H. Seeck ◽  
C. Deiter ◽  
K. Pflaum ◽  
F. Bertam ◽  
A. Beerlink ◽  
...  

The new third-generation synchrotron radiation source PETRA III located at the Deutsches Elektronen-Synchrotron DESY in Hamburg, Germany, has been operational since the second half of 2009. PETRA III is designed to deliver hard X-ray beams with very high brilliance. As one of the first beamlines of PETRA III the high-resolution diffraction beamline P08 is fully operational. P08 is specialized in X-ray scattering and diffraction experiments on solids and liquids where extreme high resolution in reciprocal space is required. The resolving power results in the high-quality PETRA III beam and unique optical elements such as a large-offset monochromator and beryllium lens changers. A high-precision six-circle diffractometer for solid samples and a specially designed liquid diffractometer are installed in the experimental hutch. Regular users have been accepted since summer 2010.


1998 ◽  
Vol 5 (5) ◽  
pp. 1243-1249 ◽  
Author(s):  
José I. Espeso ◽  
Peter Cloetens ◽  
José Baruchel ◽  
Jürgen Härtwig ◽  
Trevor Mairs ◽  
...  

The lateral coherence length is of the order of 100 µm at the `long' (145 m) ID19 beamline of the ESRF, which is mainly devoted to imaging. Most of the optical elements located along the X-ray path can thus act as `phase objects', and lead to spurious contrast and/or to coherence degradation, which shows up as an enhanced effective angular size of the source. Both the spurious contrast and the coherence degradation are detrimental for the images (diffraction topographs, tomographs, phase-contrast images) produced at this beamline. The problems identified and the way they were solved during the commissioning of ID19 are reported. More particularly, the role of the protection foils located in the front end, the beryllium windows, the filters and the monochromator defects (scratches, dust, small vibrations) is discussed.


2009 ◽  
Vol 36 (No. 4) ◽  
pp. 133-139 ◽  
Author(s):  
S.Z. Xin ◽  
Y.J. Song ◽  
C. Lv ◽  
Y.K. Rui ◽  
F.S. Zhang ◽  
...  

Consumption of vegetables is one of the most important ways of providing the body with mineral elements. However, it is not clear how mineral elements are distributed in different organs of vegetables, especially vegetables grown in greenhouses. The distribution of mineral elements in the root and leaves of greenhouse spinach was determined using synchrotron radiation XRF, the results indicated that the amount of various elements in different parts of the leaves, roots and stems were inequable. Generally, the content of the elements in the root base were slightly higher than in the other parts. The amounts in the root apices were much lower than those in the other parts while the amount of every element decreased gradually from the root base to the root apices. In stems, the amount of K, Ca, Fe, Ni, and Zn were higher in the base of the stem than in the top of stem while the amounts of Co and Cu were higher in the top of the stem than in the base of stem. From all the elements detected in the stem, Mn was at the lowest concentration. In leaves, Co and Zn were primarily accumulated around the main veins and the amount of Mn in the tip of the leaf was higher than in the other parts. In contrast, K, Ca, Ni, and Cu were higher in the center of the leaf.


2002 ◽  
Vol 09 (02) ◽  
pp. 937-941 ◽  
Author(s):  
P. LUCHES ◽  
C. GIOVANARDI ◽  
T. MOIA ◽  
S. VALERI ◽  
F. BRUNO ◽  
...  

CoO layers have been grown by exposing to oxygen the (001) body-centered-tetragonal (bct) surface of a Co ultrathin film epitaxially grown on Fe(001). Different oxide thicknesses in the 2–15 ML range have been investigated by means of synchrotron-radiation-based techniques. X-ray photoelectron spectroscopy has been used to check the formation of the oxide films; X ray photoelectron diffraction has given information concerning the symmetry of their unit cell; grazing incidence X-ray diffraction has allowed to evaluate precisely their in-plane lattice constant. The films show a CoO(001) rocksalt structure, rotated by 45° with respect to the bct Co substrate, with the [100] direction parallel to the substrate [110] direction. Their in-plane lattice constant increases as a function of thickness, to release the in-plane strain due to the 3% mismatch between the bulk CoO phase and the underlying substrate.


1998 ◽  
Vol 5 (3) ◽  
pp. 239-245 ◽  
Author(s):  
A. Erko ◽  
M. Veldkamp ◽  
W. Gudat ◽  
N. V. Abrosimov ◽  
S. N. Rossolenko ◽  
...  

Using X-ray diffractometry and spectral measurements, the structure and properties of graded X-ray optical elements have been examined. Experimental and theoretical data on X-ray supermirrors, which were prepared by the magnetron sputtering technique using precise thickness control, are reported. Measurements on graded aperiodic Si1−x Ge x single crystals, which were grown by the Czochralski technique, are also presented. The lattice parameter of such a crystal changes almost linearly with increasing Ge concentration. The measurements indicate that Si1−x Ge x crystals with concentrations up to 7 at.% Ge can be grown with a quality comparable to that of pure Si crystals.


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