scholarly journals Objective Grating Soft X-Ray Spectroscopy of Compact Binary X-Ray Sources

1984 ◽  
Vol 86 ◽  
pp. 80-83
Author(s):  
S.M. Kahn ◽  
S.D. Vrtilek ◽  
L. Chiappetti ◽  
N.E. White

The presence of objective transmission gratings on the two recent X-ray telescope experiments, the Einstein and EXOSAT Observatories, has opened up a new avenue of research in X-ray astronomy by enabling us, for the first time, to obtain moderate-to-high resolution spectra of cosmic sources in the soft X-ray band (λ ~ 5–200 Å). Both experiments incorporated gold bar transmission gratings with line densities of 500 1/mm and 1000 1/mm which could be inserted into the X-ray optical path at the exit from a grazing incidence mirror. At short wavelengths, the resolution was determined principally by the spatial resolution of the detector-telescope combination. For Einstein, this was Δλ ~ 0.4 Å for the 1000 1/mm grating and ~ 0.8 Å for the 500 1/mm grating. For EXOSAT, the resolution was somewhat worse: Δλ ~ 1.5 Å for the 1000 1/mm grating, and ~ 3 Å for the 500 1/mm grating. (More complete descriptions of these instruments can be found in Seward et al. 1982 and de Korte et al. 1981.)

1998 ◽  
Vol 4 (S2) ◽  
pp. 352-353
Author(s):  
W. Meyer-Ilse ◽  
J. T. Brown ◽  
C. Magowan ◽  
J. Yeung ◽  
K. E. Kurtis ◽  
...  

The Center for X-ray Optics (CXRO) built and operates a high-resolution soft x-ray microscope (XM-1) at the Advanced Light Source in Berkeley. We report on the use of this instrument in a variety of scientific fields, including biology, civil engineering and environmental sciences.The microscope is a conventional (full field) x-ray microscope, which uses zone plate lenses to provide high resolution transmission images. The optical setup is similar to the Göttingen x-ray microscope, operated at the BESSY synchrotron radiation facility in Berlin, Germany. A condenser zone plate, fabricated by the Göttingen group, is illuminating the sample and an objective zone plate, fabricated by Erik Anderson (CXRO), is forming an enlarged image on an x-ray CCD camera. While the optical path of the microscope is in vacuum, the sample is at atmospheric pressure, flushed by helium. The spatial resolution of our microscope is 43 nm, measured as the distance from 10%-90% intensity in the image of a knife-edge.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.


2001 ◽  
Vol 19 (2) ◽  
pp. 285-293 ◽  
Author(s):  
T.A. PIKUZ ◽  
A. YA. FAENOV ◽  
M. FRAENKEL ◽  
A. ZIGLER ◽  
F. FLORA ◽  
...  

The shadow monochromatic backlighting (SMB) scheme, a modification of the well-known soft X-ray monochromatic backlighting scheme, is proposed. It is based on a spherical crystal as the dispersive element and extends the traditional scheme by allowing one to work with a wide range of Bragg angles and thus in a wide spectral range. The advantages of the new scheme are demonstrated experimentally and supported numerically by ray-tracing simulations. In the experiments, the X-ray backlighter source is a laser-produced plasma, created by the interaction of an ultrashort pulse, Ti:Sapphire laser (120 fs, 3–5 mJ, 1016 W/cm2 on target) or a short wavelength XeCl laser (10 ns, 1–2 J, 1013 W/cm2 on target) with various solid targets (Dy, Ni + Cr, BaF2). In both experiments, the X-ray sources are well localized spatially (∼20 μm) and are spectrally tunable in a relatively wide wavelength range (λ = 8–15 Å). High quality monochromatic (δλ/λ ∼ 10−5–10−3) images with high spatial resolution (up to ∼4 μm) over a large field of view (a few square millimeters) were obtained. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in a wide range of Bragg angles (35° < Θ < 90°) is demonstrated for the first time.


2013 ◽  
Vol 46 (6) ◽  
pp. 1544-1550 ◽  
Author(s):  
Matej Jergel ◽  
Peter Šiffalovič ◽  
Karol Végsö ◽  
Eva Majková ◽  
Dušan Korytár ◽  
...  

The application of V-shaped channel-cut GeSi(220) and Ge(220) monochromators for one-dimensional extreme X-ray beam compression was tested on a table-top setup for grazing-incidence small-angle X-ray scattering (GISAXS) with a microfocus source. A lattice constant gradient and different asymmetry angles of the diffractors were employed to enhance the compression factor to 21 and 15, respectively. It was demonstrated that the output beam parameters in terms of the size, divergence, photon flux and spectral bandwidth surpass those of the slit collimators used traditionally in GISAXS. A beam size far below 100 µm allows a high-resolution spatial GISAXS mapping, while the reciprocal space resolution of ∼500 nm approaches the level of synchrotron measurements and allows a fast one-shot detection of high-resolution GISAXS patterns. An oversampling shifts the detection limit up to ∼1 µm. The very short design of the compact high-resolution table-top GISAXS setup is another advantage of the extreme beam compression. Benefits of V-shaped monochromators for medium-resolution X-ray diffraction experiments as a bonus application are demonstrated by a comparison with parallel channel-cut monochromators combined with a slit.


2013 ◽  
Vol 46 (4) ◽  
pp. 945-952 ◽  
Author(s):  
D. Korytár ◽  
P. Vagovič ◽  
K. Végsö ◽  
P. Šiffalovič ◽  
E. Dobročka ◽  
...  

While channel-cut crystals, in which the diffracting surfaces in an asymmetric cut are kept parallel, can provide beam collimation and spectral beam shaping, they can in addition provide beam compression or expansion if the cut is V-shaped. The compression/expansion ratio depends in this case on the total asymmetry factor. If the Ge(220) diffraction planes and a total asymmetry factor in excess of 10 are used, the rocking curves of two diffractors will have a sufficient overlap only if the second diffractor is tuned slightly with respect to the first one. This study compares and analyses several ways of overcoming this mismatch, which is due to refraction, when the CuKα1beam is compressed 21-fold in a V21 monochromator. A more than sixfold intensity increase was obtained if the matching was improved either by a compositional variation or by a thermal deformation. This provided an intensity gain compared with the use of a simple slit in a symmetrical channel-cut monochromator. The first attempt to overcome the mismatch by introducing different types of X-ray prisms for the required beam deflection is described as well. The performance of the V-shaped monochromators is demonstrated in two applications. A narrow collimated monochromatic beam obtained in the beam compressing mode was used for high-resolution grazing-incidence small-angle X-ray scattering measurements of a silicon sample with corrupted surface. In addition, a two-dimensional Bragg magnifier, based on two crossed V15 channel monochromators in beam expansion mode and tuned by means of unequal asymmetries, was successfully applied to high-resolution imaging of test structures in combination with a Medipix detector.


Author(s):  
Alexander M. Antipin ◽  
Natalia I. Sorokina ◽  
Olga A. Alekseeva ◽  
Alexandra N. Kuskova ◽  
Elena P. Kharitonova ◽  
...  

A single crystal of Nd5Mo3O16with lead partly substituting for neodymium, which has a fluorite-like structure, was studied by precision X-ray diffraction, high-resolution transmission microscopy and EDX microanalysis. The crystal structure is determined in the space group Pn\bar 3n. It was found that the Pb atoms substitute in part for Nd atoms in the structure and are located in the vicinity of Nd2 positions. Partial substitutions of Mo cations for Nd positions and of Nd for Mo positions in crystals of theLn5Mo3O16oxide family are corroborated by X-ray diffraction for the first time. The first experimental verification of the location of an additional oxygen ion in the voids abutting MoO4tetrahedra was obtained.


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