Alignment of the aberration-free XUV Raman spectrometer at FLASH

2019 ◽  
Vol 26 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Mykola Biednov ◽  
Günter Brenner ◽  
Benjamin Dicke ◽  
Holger Weigelt ◽  
Barbara Keitel ◽  
...  

An extreme-ultraviolet (XUV) double-stage Raman spectrometer is permanently installed as an experimental end-station at the PG1 beamline of the soft X-ray/XUV free-electron laser in Hamburg, FLASH. The monochromator stages are designed according to the Czerny–Turner optical scheme, adapted for the XUV photon energy range, with optical elements installed at grazing-incidence angles. Such an optical scheme along with the usage of off-axis parabolic mirrors for light collimation and focusing allows for aberration-free spectral imaging on the optical axis. Combining the two monochromators in additive dispersion mode allows for reaching high resolution and superior stray light rejection, but puts high demands on the quality of the optical alignment. In order to align the instrument with the highest precision and to quantitatively characterize the instrument performance and thus the quality of the alignment, optical laser interferometry, Hartmann–Shack wavefront-sensing measurements as well as off-line soft X-ray measurements and extensive optical simulations were conducted. In this paper the concept of the alignment scheme and the procedure of the internal optical alignment are presented. Furthermore, results on the imaging quality and resolution of the first monochromator stage are shown.

1991 ◽  
Vol 239 ◽  
Author(s):  
J. M. Hudson ◽  
A. R. Powell ◽  
D. K. Bowen ◽  
M. Wormington ◽  
B. K. Tanner ◽  
...  

ABSTRACTWe demonstrate the use of x-ray diffraction to provide accurate compositional information, together with grazing incidence reflectivity to provide information on layer thicknesses and surface and interface roughnesses, on Si/Si1-xGex superlattice structures of less than 200nm total thickness.The quality of SiGe interfaces has been investigated in superlattices where x varies from 0.1 to 0.5. At low Ge compositions the interfaces are shown to be smooth to a few angstroms. However, as the Ge composition in the SiGe layer approaches 50%, severe roughness is observed at the SiGe to Si interfaces, although the Si to SiGe interfaces remain relatively smooth.Upon annealing for one hour at 850°C the Ge diffuses outwards from the SiGe layers and can be closely modelled by inclusion of a (2.4±0.3)nm linearly graded layer either side of the SiGe layer into a simulation program. The long range roughness at the SiGe to Si interface is lost upon annealing leaving only a short range roughness of similar size to the Si to SiGe interface roughness.Reflectivity measurements have been shown to distinguish between interface roughness and interdiffusion for the annealed system.


1988 ◽  
Vol 102 ◽  
pp. 303
Author(s):  
A.V. Vinogradov

SummaryTi, Si, C, Be and LiF have been studied as coatings for normal incidence (multilayers) and grazing incidence (steering many-fold reflection mirrors) optical elements. The multilayers have been tested with soft (130+250 Å and hard (1.54 Å) X-rays. From these measurements the multilayer parameters have been deduced.The carbon and lithium fluorine steering mirrors showed the reflection of 10+60% for the turning angles of 30 and 45 degrees and two wavelengths of 44.7 Å and 67.6 Å. The perspectives of other materials are also discussed.


1994 ◽  
Author(s):  
Paolo Conconi ◽  
U. Bergamini ◽  
Oberto Citterio ◽  
Giuseppe Crimi ◽  
Mauro Ghigo ◽  
...  

2006 ◽  
Vol 77 (10) ◽  
pp. 10F306 ◽  
Author(s):  
P. Beiersdorfer ◽  
M. Bitter ◽  
L. Roquemore ◽  
J. K. Lepson ◽  
M.-F. Cu

2002 ◽  
Vol 41 (35) ◽  
pp. 7384 ◽  
Author(s):  
Chang Chang ◽  
Patrick Naulleau ◽  
Erik Anderson ◽  
Kristine Rosfjord ◽  
David Attwood

2014 ◽  
Vol 47 (2) ◽  
pp. 613-618 ◽  
Author(s):  
M. Soccio ◽  
N. Alayo ◽  
I. Martín-Fabiani ◽  
D. R. Rueda ◽  
M. C. García-Gutiérrez ◽  
...  

Grazing-incidence small-angle X-ray scattering (GISAXS) can be used to characterize the replica quality of polymer gratings prepared by thermal nanoimprint lithography (NIL). Here it is shown using GISAXS experiments that a series of NIL polymer gratings with different line quality present characteristic features that can be associated with the level of defects per line. Both stamps and NIL polymer gratings exhibit characteristic semicircle-like GISAXS patterns. However NIL polymer gratings with defective lines exhibit GISAXS patterns with an excess of diffuse scattering as compared to those of the corresponding stamps. In a first approach, this effect is attributed to a reduction of the effective length of the lines diffracting coherently as the number of defects per line increases.


Author(s):  
Alexey Kirichenko ◽  
Sergey Kuzin ◽  
Sergey Shestov ◽  
Artem Ulyanov ◽  
Andrey Pertsov ◽  
...  

We present a description of the recent advances in the development of the KORTES assembly—the first solar oriented mission designed for the Russian segment of the International Space Station. KORTES consists of several imaging and spectroscopic instruments collectively covering a wide spectral range extending from extreme ultraviolet (EUV) wavelengths to X-rays. The EUV telescopes inside KORTES will trace the origin and dynamics of various solar phenomena, e.g., flares, CMEs, eruptions etc. EUV spectra provided by grazing-incidence spectroheliographs will enable precise DEM-diagnostics during these events. The monochromatic X-ray imager will observe the formation of hot plasma in active regions and outside them. The SolpeX module inside KORTES will offer an opportunity to measure fluxes, Doppler shifts and polarization of soft X-ray emission both in lines and continuum. SolpeX observations will contribute to studies of particle beams and chromospheric evaporation. The instrumentation of KORTES will employ a variety of novel multilayer and crystal optics. The deployment of KORTES is planned for 2024.


2020 ◽  
Vol 27 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Werner Jark

The most efficient diffraction at a periodic grating structure is expected to take place when the incident radiation can be considered to have been specularly reflected off the inclined part of grooves that are positioned parallel to the trajectory of the incident beam. Very encouraging results for this configuration, in which the diffraction takes place off-plane, have been reported recently for a grating to be used in a spectrometer for space science investigations. This grating provided high efficiency for a relatively large groove density and a large blaze angle. High efficiency was observed even in higher diffraction orders up to the fourth order. Here the performance parameters, especially for the combination of diffraction efficiency and achievable spectral resolution, will be discussed for a grating used in a grazing-incidence plane-grating monochromator for monochromatization of synchrotron radiation in the extreme ultraviolet (EUV) and soft X-ray range with photon energies between 30 eV and 2000 eV. It is found that the instrument can provide competitive spectral resolution in comparison with the use of in-plane diffraction. In the case of comparable spectral resolution, the off-plane diffraction is found to provide superior efficiency.


1987 ◽  
Vol 103 ◽  
Author(s):  
Troy W. Barbee

ABSTRACTMultilayers are man-made microstructures engineered to vary in depth that are now of sufficient quality to be used as x-ray, soft x-ray and extreme ultraviolet optics. Gratings are in-plane man-made microstructures which have been used as optic elements for most of this century. Joining of these two optical elements to form combined microstructure optics has the potential for greatly enhancing both the resolution and the throughput attainable in these spectral ranges. Experimental results for multilayer gratings are presented and discussed. It will be demonstrated that multilayer diffraction gratings act as x-ray prisms and are high efficiency dispersion elements.


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