Study of TaSi2-Si Crystals with High Energy Synchrotron Radiation as Tunable Wide-bandpass Monochromator and Analyzer Optics

2001 ◽  
Vol 678 ◽  
Author(s):  
U. Rütt ◽  
S.R. Stock ◽  
Z.U. Rek
Keyword(s):  
Synchrotron Radiation ◽  
Silicon Crystal ◽  
Incident Beam ◽  
High Energy ◽  
Crystal Thickness ◽  
Rocking Curve ◽  
Analyzer Crystal ◽  
Transmission Geometry ◽  
Integrated Intensity

AbstractSingle crystals of the in situ composite TaSi2-Si are candidates for wide bandpass monochromators and analyzers for x-ray experiments. Two large crystals (32 × 39 × 7 mm3 and 32 x 39 x 30 mm3) were studied in detail using 115 keV synchrotron radiation at the BESSRC beamline at the APS. For transmission geometry, the Si(111) reflection and 39 mm crystal thickness, rocking curve widths of 95 arc sec with reflectivities of 50% were measured over the entire crystal. Turning the crystal to an angle of 45° to the incident beam and translating it through the beam allowed investigation of the influence of crystal thickness on diffracted intensity. For sample thicknesses ranging between 5 mm and 12.5 mm, the full width at half maximum (FWHM) of the rocking curve increased linearly from 29 arc sec to 53 arc sec. The greatest gain in integrated intensity was obtained for 8-9 mm thickness where FWHM = 40 arc sec. If this crystal were used as a monochromator for synchrotron radiation, it would provide 40 times more intensity than a perfect silicon crystal and an energy bandwidth of 1 keV at 115 keV photon energy. With the increase of the rocking curve FWHM, a plateau across the peak maximum developed; its width increased from 5 arc sec to 25 arc sec when the crystal thickness increased from 5 mm to 12.5 mm, respectively. This plateau allows these crystals to be used as analyzer crystals in diffraction experiments, i.e., as very narrow slits to suppress background. A plateau width of about 5-20 arc sec for the analyzer crystal is needed to insure that the entire intensity scattered from a sample is delivered to the detector. The simple expedient of changing the crystal thickness alters the plateau width of the analyzer crystal and tunes its acceptance to the needs of the sample under study.

scholarly journals Investigation of High-Energy Ion-Irradiated MA957 Using Synchrotron Radiation under In-Situ Tension

Materials ◽  
2016 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Kun Mo ◽  
Di Yun ◽  
Yinbin Miao ◽  
Xiang Liu ◽  
Michael Pellin ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
High Energy

Micro-X-Ray Fluorescence Analysis on a Synchrotron Radiation Wiggler Beam Line

1991 ◽  
Vol 35 (B) ◽  
pp. 995-1000
Author(s):  
J.V. Gilfrich ◽  
E.F. Skelton ◽  
S.B. Qadri ◽  
N.E. Moulton ◽  
D.J. Nagel ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
National Laboratory ◽  
Incident Beam ◽  
Fluorescence Analysis ◽  
High Energy ◽  
Brookhaven National Laboratory ◽  
Beam Line ◽  
X Rays ◽  
X Ray ◽  
Electron Orbit

AbstractIt has been well established over recent years that synchrotron radiation possesses some unique features as a source of primary x-rays for x-ray fluorescence analysis. Advantage has been taken of the high intensity emanating from the bending magnets of storage rings to develop x-ray microprobes utilizing apertures or focussing optics, or both, to provide a beam spot at the specimen of the order of micrometers. The use of insertion devices wigglers and undulatora, can further increase the available intensity, especially for the high energy photons. Beam Line X-17C at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory, accepts the unmodified continuum radiation from a superconducting wiggler in the storage ring. Some initial XRF measurements have been made on this beam line using apertures in the 10 to 100 micrometer range. The fluorescent radiation was measured by an intrinsic Ge detector having an energy resolution of 300 eV at 15 kev, and located at 90° to the incident beam in the plane of the electron orbit. In samples containing many elements, detection limits of a few ppm were achieved with 100 μm beams.

scholarly journals Fast-current-heating devices to study in situ phase formation in metallic glasses by using high-energy synchrotron radiation

2020 ◽  
Vol 91 (7) ◽  
pp. 073901
Author(s):  
Jiri Orava ◽  
Konrad Kosiba ◽  
Xiaoliang Han ◽  
Ivan Soldatov ◽  
Olof Gutowski ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Phase Formation ◽  
Metallic Glasses ◽  
High Energy

Thermal Stability of Retained Austenite in Low Alloyed TRIP-Steel Determined by High Energy Synchrotron Radiation

2013 ◽  
Vol 772 ◽  
pp. 129-133
Author(s):  
Stefan Brauser ◽  
Arne Kromm ◽  
Eitan Dabah ◽  
Thomas Kannengiesser ◽  
Michael Rethmeier
Keyword(s):  
Synchrotron Radiation ◽  
High Energy ◽  
Heating Process ◽  
Austenitic Phase ◽  
Trip Steels ◽  
The Stability ◽  
In Situ Diffraction ◽  
Kinetics Of ◽  
Thermal Stability Of

TRIP-steels offer a good combination between strength and ductility. Therefore TRIP-steels are widely used in the automobile industries. The aim of this work is to study the stability of involved phases during heating and to identify the kinetics of the occuring phase transformations. For that purpose, in-situ diffraction measurements, using high energy synchrotron radiation were conducted. The analysis revealed the decomposition of the metastable austenitic phase into carbide and ferrite along the heating process and the regeneration of the austenite by further heating of the sample.

In Situ High-Energy Synchrotron Radiation Study of Boehmite Formation, Growth, and Phase Transformation to Alumina in Sub- and Supercritical Water

2009 ◽  
Vol 15 (48) ◽  
pp. 13381-13390 ◽  
Author(s):  
Nina Lock ◽  
Martin Bremholm ◽  
Mogens Christensen ◽  
Jonathan Almer ◽  
Yu-Sheng Chen ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Synchrotron Radiation ◽  
Supercritical Water ◽  
High Energy ◽  
Radiation Study

In situ analysis of hydrogen behaviour in stainless steels by high energy synchrotron radiation

2011 ◽  
Vol 528 (3) ◽  
pp. 1608-1614 ◽  
Author(s):  
E. Dabah ◽  
Th. Kannengiesser ◽  
D. Eliezer ◽  
Th. Boellinghaus
Keyword(s):  
Synchrotron Radiation ◽  
Stainless Steels ◽  
High Energy ◽  
In Situ Analysis

Synchrotron Radiation Study on Alloy 617 and Alloy 230 for VHTR Application

2011 ◽  
Author(s):  
Kun Mo ◽  
Hsiao-Ming Tung ◽  
Xiang Chen ◽  
Weiying Chen ◽  
Jon B. Hansen ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Internal Stress ◽  
Applied Stress ◽  
Lattice Strain ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Alloy 617 ◽  
X Ray

High-energy synchrotron radiation has proven to be a powerful technique for investigating fundamental deformation processes for various materials, particularly metals and alloys. In this study, high-energy synchrotron X-ray diffraction (XRD) was used to evaluate Alloy 617 and Alloy 230, both of which are top candidate structural materials for the Very-High-Temperature Reactor (VHTR). Uniaxial tensile experiments using in-situ high-energy X-ray exposure showed the substantial advantages of this synchrotron technique. First, the small volume fractions of carbides, e.g. ∼6% of M6C in Alloy 230, which are difficult to observe using lab-based X-ray machines or neutron scattering facilities, were successfully examined using high-energy X-ray diffraction. Second, the loading processes of the austenitic matrix and carbides were separately studied by analyzing their respective lattice strain evolutions. In the present study, the focus was placed on Alloy 230. Although the Bragg reflections from the γ matrix behave differently, the lattice strain measured from these reflections responds linearly to external applied stress. In contrast, the lattice strain evolution for carbides is more complicated. During the transition from the elastic to the plastic regime, carbide particles experience a dramatic loading process, and their internal stress rapidly reaches the maximum value that can be withstood. The internal stress for the particles then decreases slowly with increasing applied stress. This indicates a continued particle fracture process during plastic deformations of the γ matrix. The study showed that high-energy synchrotron X-ray radiation, as a non-destructive technique for in-situ measurement, can be applied to ongoing material research for nuclear applications.

In Situ Synchrotron Measurements of Oxide Growth Strains

2005 ◽  
Vol 490-491 ◽  
pp. 287-293 ◽  
Author(s):  
Jonathan Almer ◽  
Geoffrey A. Swift ◽  
John A. Nychka ◽  
Ersan Üstündag ◽  
David R. Clarke
Keyword(s):  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
High Energy ◽  
Oxide Growth ◽  
X Rays ◽  
Pure Alumina ◽  
Transmission Geometry ◽  
Residual Strains

Synchrotron x-rays are used for in situ determination of oxide strain, during oxide formation on a Kanthal A1 FeCrAlZr substrate at 1160°C. The measurements rely on use of high-energy (~80keV) x-rays and transmission geometry, and the methodology of the strain measurements is presented. Oxide growth strains at elevated temperature, relative to pure alumina, were seen to be small, while temperature excursions induced significant strains. Furthermore, significant strain relaxation was observed during isothermal holds, suggesting oxide creep as a major relaxation mechanism. Upon cooling to room temperature, significant residual strains developed, with a corresponding in-plane residual stress of -3.7 GPa.

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