X-Ray Microscopy Projects In Aarhus

1997 ◽  
Vol 3 (S2) ◽  
pp. 907-908
Author(s):  
R. Medenwaldt ◽  
J. Abraham ◽  
E. E.UggerhØj ◽  
F. Vollrath ◽  
E. SØgaard
Keyword(s):  
Synchrotron Radiation ◽  
Light Microscopy ◽  
Atmospheric Pressure ◽  
Ccd Camera ◽  
Zone Plate ◽  
X Rays ◽  
Aqueous Samples ◽  
X Ray ◽  
Liquid Layer Thickness ◽  
Better Than

X-ray microscopy with soft X-rays is well suited for investigations of aqueous samples of some microns thickness when the resolution is required to be better than in visible light microscopy an not better than 30 nm. Sample preparation is as simple as for light microscopy, i.e. no fixation or metal coating is needed.In Aarhus, an X-ray microscope is used for investigations in fields as biology, medicine and soil sciences. A ray diagram of the Aarhus X-ray microscope is shown in Fig.l. Synchrotron radiation at a wavelength of 2.4 nm from the Aarhus Storage Ring is focused by a condenser zone plate onto an object. Another zone plate as an objective behind the object forms the image on a CCD camera. Objects are located under atmospheric pressure. For dry samples, almost any kind of holder can be mounted in the microscope. Wet samples are placed between thin silicon foils in a sealed chamber. With typical liquid layer thickness of 5-15 µm, samples can be kept in the chamber for many hours without drying out.

Synchrotron Radiation Hard X-Ray Microprobe by Multilayer Fresnel Zone Plate

1998 ◽  
Vol 524 ◽  
Author(s):  
S. Tamura ◽  
K. Ohtani ◽  
M. Yasumoto ◽  
K. Murali ◽  
N. Kamuo ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
High Performance ◽  
Fresnel Zone ◽  
Deposition Process ◽  
Spot Size ◽  
Zone Plate ◽  
Fresnel Zone Plate ◽  
X Rays ◽  
Sputtering Deposition ◽  
X Ray

ABSTRACTA hard X-ray microbeam with submicrometer spot size from synchrotron radiation (SR) sources is expected to add a new dimension to various X-ray analysis methods. A Fresnel zone plate (FZP) is one of the promising focusing elements for X-rays. In order to develop high performance multilayer FZP for use in the hard X-ray region, Cu/Al concentric multilayers were fabricated by use of a DC sputtering deposition process. Lower Ar gas pressure or higher rotating speed of a wire substrate has been effective in forming smoother multilayer interfaces. From a focusing test of the Cu/Al FZP (100-zones) by the SR (λ= 0.154nm), microbeams of 1.5 μm φ and 0.8 μm φ have been achieved for the first- and third-order focal beams, respectively.

High Spatial Resolution Soft X-Ray Microscopy and Microanalysis of Thick and Hydrated Materials

1998 ◽  
Vol 4 (S2) ◽  
pp. 352-353
Author(s):  
W. Meyer-Ilse ◽  
J. T. Brown ◽  
C. Magowan ◽  
J. Yeung ◽  
K. E. Kurtis ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Atmospheric Pressure ◽  
High Spatial Resolution ◽  
Ccd Camera ◽  
Optical Path ◽  
Zone Plate ◽  
Full Field ◽  
X Ray ◽  
Scientific Fields

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.

Direct-write X-ray lithography using a hard X-ray Fresnel zone plate

2015 ◽  
Vol 22 (3) ◽  
pp. 781-785 ◽  
Author(s):  
Su Yong Lee ◽  
Do Young Noh ◽  
Hae Cheol Lee ◽  
Chung-Jong Yu ◽  
Yeukuang Hwu ◽  
...  
Keyword(s):  
Proximity Effect ◽  
Fresnel Zone ◽  
Lateral Spread ◽  
Zone Plate ◽  
Fresnel Zone Plate ◽  
Direct Write ◽  
X Rays ◽  
X Ray ◽  
Better Than ◽  
Outermost Zone

Results are reported of direct-write X-ray lithography using a hard X-ray beam focused by a Fresnel zone plate with an outermost zone width of 40 nm. An X-ray beam at 7.5 keV focused to a nano-spot was employed to write arbitrary patterns on a photoresist thin film with a resolution better than 25 nm. The resulting pattern dimension depended significantly on the kind of underlying substrate, which was attributed to the lateral spread of electrons generated during X-ray irradiation. The proximity effect originated from the diffuse scattering near the focus and electron blur was also observed, which led to an increase in pattern dimension. Since focusing hard X-rays to below a 10 nm spot is currently available, the direct-write hard X-ray lithography developed in this work has the potential to be a promising future lithographic method.

scholarly journals Observations of X-rays from Laboratory Sparks in Air at Atmospheric Pressure under Negative Switching Impulse Voltages

Atmosphere ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 169 ◽  
Author(s):  
Mahbubur Rahman ◽  
Pasan Hettiarachchi ◽  
Vernon Cooray ◽  
Joseph Dwyer ◽  
Vladimir Rakov ◽  
...  
Keyword(s):  
Rise Time ◽  
Atmospheric Pressure ◽  
Opposite Polarity ◽  
X Rays ◽  
X Ray ◽  
Impulse Voltage ◽  
First Time ◽  
Switching Impulses ◽  
Low Rate

We present observations of X-rays from laboratory sparks created in the air at atmospheric pressure by applying an impulse voltage with long (250 µs) rise-time. X-ray production in 35 and 46 cm gaps for three different electrode configurations was studied. The results demonstrate, for the first time, the production of X-rays in gaps subjected to switching impulses. The low rate of rise of the voltage in switching impulses does not significantly reduce the production of X-rays. Additionally, the timing of the X-ray occurrence suggests the possibility that the mechanism of X-ray production by sparks is related to the collision of streamers of opposite polarity.

Applications of High-Resolution Powder X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 7-14 ◽  
Author(s):  
Andrew N. Fitch
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Structural Characterisation ◽  
Pdf Analysis

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.

Residual Stress Measurement around the Interface of Copper Bicrystal Deformed by Uniaxial Extension

2010 ◽  
Vol 64 ◽  
pp. 125-134
Author(s):  
Hanabusa Takao ◽  
Ayumi Shiro ◽  
Tatsuya Okada
Keyword(s):  
Residual Stress ◽  
Synchrotron Radiation ◽  
Grain Boundary ◽  
Residual Stresses ◽  
Uniaxial Extension ◽  
Kink Band ◽  
X Rays ◽  
X Ray ◽  
Kink Bands ◽  
Crystal Orientations

Residual stresses of a copper bicrystal were measured by X-ray diffraction and synchrotron radiation. A copper bicrystal specimen with a 90-degree tilt boundary was fabricated by the Brigdman technique. After the plastic extension of 30%, kink bands developed in a deformed matrix along the grain boundary. In this study, we focused on the residual stress distribution along the transverse direction of the specimen surface and the residual stresses in deformed matrix and kink band near the grain boundary. Residual stresses were evaluated by the X-ray single crystal measurement method. Stereographic projections were used to determine crystal orientations of deformed regions. It was found that crystal orientations were different between the deformed matrix and the kink band. Residual stresses in the direction along the grain boundary were compressive in the vicinity of the boundary and tensile in the region apart from the boundary. Residual stresses in the kink band were large in compression in compared with those in the deformation matrix. The difference in the results between X-rays and synchrotron radiation suggests that there is a depth variation in the deformation and therefore the residual stress development.

scholarly journals Synchrotron radiation X-ray tomographic microscopy (SRXTM) of brachiopod shell interiors for taxonomy: Preliminary report

2010 ◽  
pp. 109-117 ◽  
Author(s):  
Neda Motchurova-Dekova ◽  
David Harper
Keyword(s):  
Synchrotron Radiation ◽  
Three Dimensional ◽  
X Rays ◽  
X Ray ◽  
Fine Grained ◽  
Internal Structures ◽  
Efficient Alternative ◽  
Micro Tomography ◽  
Light Beams ◽  
Non Destructive

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.

Accelerator-based X-ray sources: synchrotron radiation, X-ray free electron lasers and beyond

2019 ◽  
Vol 377 (2147) ◽  
pp. 20180231 ◽  
Author(s):  
Tetsuya Ishikawa
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Free Electron ◽  
Continuous Wave ◽  
Transitional Period ◽  
Light Sources ◽  
X Rays ◽  
Free Electron Lasers ◽  
Beam Emittance ◽  
X Ray

The evolution of synchrotron radiation (SR) sources and related sciences is discussed to explain the ‘generation’ of the SR sources. Most of the contemporary SR sources belong to the third generation, where the storage rings are optimized for the use of undulator radiation. The undulator development allowed to reduction of the electron energy of the storage ring necessary for delivering 10 keV X-rays from the initial 6–8 GeV to the current 3 Gev. Now is the transitional period from the double-bend-achromat lattice-based storage ring to the multi-bend-achromat lattice to achieve much smaller electron beam emittance. Free electron lasers are the other important accelerator-based light sources which recently reached hard X-ray regime by using self-amplified spontaneous emission scheme. Future accelerator-based X-ray sources should be continuous wave X-ray free electron lasers and pulsed X-ray free electron lasers. Some pathways to reach the future case are discussed. This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.

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