Thickness variations in x‐ray filters and laser targets

1984 ◽  
Vol 45 (5) ◽  
pp. 504-506 ◽  
Author(s):  
R. R. Whitlock ◽  
J. A. Sprague
Keyword(s):  
X Ray ◽  
Thickness Variations

scholarly journals Reconstruction of the near-field distribution in an X-ray waveguide array

2017 ◽  
Vol 50 (3) ◽  
pp. 701-711 ◽  
Author(s):  
Qi Zhong ◽  
Lars Melchior ◽  
Jichang Peng ◽  
Qiushi Huang ◽  
Zhanshan Wang ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Field Distribution ◽  
Phase Retrieval ◽  
Near Field ◽  
Field Pattern ◽  
Waveguide Array ◽  
X Ray ◽  
Field Patterns ◽  
Thickness Variations ◽  
Far Field Pattern

Iterative phase retrieval has been used to reconstruct the near-field distribution behind tailored X-ray waveguide arrays, by inversion of the measured far-field pattern recorded under fully coherent conditions. It is thereby shown that multi-waveguide interference can be exploited to control the near-field distribution behind the waveguide exit. This can, for example, serve to create a secondary quasi-focal spot outside the waveguide structure. For this proof of concept, an array of seven planar Ni/C waveguides are used, with precisely varied guiding layer thickness and cladding layer thickness, as fabricated by high-precision magnetron sputtering systems. The controlled thickness variations in the range of 0.2 nm results in a desired phase shift of the different waveguide beams. Two kinds of samples, a one-dimensional waveguide array and periodic waveguide multilayers, were fabricated, each consisting of seven C layers as guiding layers and eight Ni layers as cladding layers. These are shown to yield distinctly different near-field patterns.

Calibration of an Energy Dispersive X-Ray Fluorescence Spectrometer

1975 ◽  
Vol 19 ◽  
pp. 473-486 ◽  
Author(s):  
A. R. Stiles ◽  
T. G. Dzubay ◽  
R. M. Baum ◽  
R. L. Walter ◽  
R. D. Willis ◽  
...  
Keyword(s):  
Thermal Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
National Bureau ◽  
Average Deviation ◽  
X Ray ◽  
Elemental Concentrations ◽  
Thermal Ionization Mass ◽  
Commercial Sources ◽  
Thickness Variations ◽  
Fluorescence Spectrometer

The purpose of this work was to develop accurate calibration standards which were fully characterized in terms of uniformity and concentration using fundamental measuring methods. Three similar sets of vacuum deposits were commercially made, each set containing the single deposits CuS, KCl, CaF2, Cr, Fe, Cu, RbNO3, SrF2, MoO3 , BaF2, and Pb. Thickness variations in each deposit were measured with PIXEA (proton induced x-ray excitation analysis) measurements taken at 6 to 8 positions along the deposit diameters. Relative elemental concentrations on corresponding deposits from each set were measured using multiple XRF intercomparisons. One set of deposits was destructively analyzed at the National Bureau of Standards with isotope dilution thermal ionization mass spectrometry (IDMS) in order to calibrate the remaining sets of vacuum deposits. The calibrated deposits were compared with standards from two commercial sources. For seven elements heavier than chlorine there was an average deviation of 13.5% between the calibrated deposits and the commercial standards. Disagreements as large as 15% were observed between standards from the two commercial suppliers.

scholarly journals X-ray fluorescence at nanoscale resolution for multicomponent layered structures: a solar cell case study

2017 ◽  
Vol 24 (1) ◽  
pp. 288-295 ◽  
Author(s):  
Bradley M. West ◽  
Michael Stuckelberger ◽  
April Jeffries ◽  
Srikanth Gangam ◽  
Barry Lai ◽  
...  
Keyword(s):  
Solar Cell ◽  
Multicomponent System ◽  
Incident Beam ◽  
Integral Form ◽  
Fluorescence Signal ◽  
Elemental Distribution ◽  
X Ray ◽  
Spatially Resolved ◽  
General Integral ◽  
Thickness Variations

The study of a multilayered and multicomponent system by spatially resolved X-ray fluorescence microscopy poses unique challenges in achieving accurate quantification of elemental distributions. This is particularly true for the quantification of materials with high X-ray attenuation coefficients, depth-dependent composition variations and thickness variations. A widely applicable procedure for use after spectrum fitting and quantification is described. This procedure corrects the elemental distribution from the measured fluorescence signal, taking into account attenuation of the incident beam and generated fluorescence from multiple layers, and accounts for sample thickness variations. Deriving from Beer–Lambert's law, formulae are presented in a general integral form and numerically applicable framework. The procedure is applied using experimental data from a solar cell with a Cu(In,Ga)Se2 absorber layer, measured at two separate synchrotron beamlines with varied measurement geometries. This example shows the importance of these corrections in real material systems, which can change the interpretation of the measured distributions dramatically.

High Resolution X-Ray Reciprocal Space Mapping of Wavy Layers

1997 ◽  
Vol 472 ◽  
Author(s):  
P. Kidd ◽  
P. F. Fewster
Keyword(s):  
High Resolution ◽  
Block Size ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Interface Roughness ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Wavy Interface ◽  
Thickness Variations ◽  
Inp Substrates

ABSTRACTWe apply the technique of High Resolution X-ray Reciprocal Space Mapping (HRRSM) to the study of wavy layers in InGaAs multilayer thin films on InP substrates. By accurately measuring the positions of the layer Bragg peaks in reciprocal space we obtain measurements of the compositions and residual coherency strains in the layers. We discuss the contributions to the diffuse scatter around the Bragg peaks from factors such as lattice tilts and interface roughness. By modelling the shapes of the diffraction profiles we obtain measurements of mosaic block size both perpendicular and parallel to the multilayer/substrate interface. We conclude that the wavy interface morphology arises predominantly from layer thickness variations rather than lattice tilts.

Thickness Variations and Surface Layers in Ultramicrotomed Sections and Their Effects on Elemental Mapping

1991 ◽  
Vol 254 ◽  
Author(s):  
T. Malls ◽  
D. Steele
Keyword(s):  
Elemental Mapping ◽  
Surface Layers ◽  
X Ray ◽  
Surface Oxides ◽  
Mass Fractions ◽  
Low Mass ◽  
Thickness Variations ◽  
Low X ◽  
Diamond Knife

AbstractWhile the thickness of ultramicrotomed sections is much more uniform than that of wedge-shaped foils, its variation is seen to be dependent on such factors as the type of material, use of embedding media, water bath interaction (anodic dissolution) and quality of the diamond knife edge. The latter also affects the thickness of surface oxides formed during sectioning. More deleterious surface layers are produced by partial breakdown and redeposition of embedding media under the electron beam. These artefacts indicate that ultramicrotomy is not the panacea for elemental X-ray mapping that might, at first thought, appear to be the case. For the example of a metal matrix composite, useable maps are obtainable, but even the best microtomed sections are limited in terms of mapping by factors such as the lengthy times for map acquisition caused by the low X-ray count rates resulting from thin specimens, particularly where low mass fractions are involved.

scholarly journals Three-dimensional visualization and quantification of the fracture mechanisms in sparse fibre networks using multiscale X-ray microtomography

2018 ◽  
Vol 474 (2215) ◽  
pp. 20180175 ◽  
Author(s):  
Victoria Krasnoshlyk ◽  
Sabine Rolland du Roscoat ◽  
Pierre J. J. Dumont ◽  
Per Isaksson ◽  
Edward Ando ◽  
...  
Keyword(s):  
Structural Changes ◽  
Crack Path ◽  
Process Zone ◽  
Three Dimensional ◽  
Optical Microscope ◽  
Fracture Mechanisms ◽  
Structural Variations ◽  
X Ray ◽  
Three Dimensional Images ◽  
Thickness Variations

The structural changes that are induced by the initiation and the propagation of a crack in a low-density paper (LDP) were studied using single edge-notched fracture tests that were imaged under an optical microscope or in laboratory or synchrotron X-ray microtomographs. The two-dimensional optical images were used to analyse the links between the mesoscale structural variations of LDP and the crack path. Medium-resolution X-ray three-dimensional images were used to analyse the variations in the thickness and local porosity of samples as well as their displacement field that were induced by the LDP fracture. High-resolution three-dimensional images showed that these mesostructural variations were accompanied by complex fibre and bond deformation mechanisms that were, for the first time, in situ imaged. These mechanisms occurred in the fracture process zone that developed ahead of the crack tip before the crack path became distinct and visible. They were at the origin of the aforementioned thickness variations that developed more particularly along the crack path. They eventually led to fibre–fibre bond detachment phenomena and crack propagation through the fibrous network. These results can be used to enhance the current structural and mechanical models for the prediction of the fracture behaviour of papers.

Influence of thin film thickness variations on pattern fidelity of X-ray masks

1986 ◽  
Vol 5 (1-4) ◽  
pp. 61-65 ◽  
Author(s):  
W.H. Brünger ◽  
H. Betz ◽  
A. Heuberger ◽  
J. Hersener
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Thin Film Thickness ◽  
X Ray ◽  
Thickness Variations
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