scholarly journals Design, development and applications of etched multilayers for soft X-ray spectroscopy

2017 ◽  
Vol 78 (2) ◽  
pp. 20702 ◽  
Author(s):  
Karine Le Guen ◽  
Rabah Benbalagh ◽  
Jean-Michel André ◽  
Jean-René Coudevylle ◽  
Philippe Jonnard
Keyword(s):  
Present Article ◽  
Spectral Resolution ◽  
Emission Band ◽  
Pyrolytic Graphite ◽  
Optical Characterization ◽  
Light Elements ◽  
Design Development ◽  
X Ray ◽  
Characteristic Emission ◽  
2D Structure

An etched multilayer, a 2D structure fabricated by etching a periodic multilayer according to the pattern of a laminar grating, is applied in the soft X-ray range to improve the spectral resolution of wavelength dispersive spectrometers. The present article gathers all the successive stages of the development of such a device optimized to analyze the characteristic emission of light elements: design, structural and optical characterization and applications to X-ray spectroscopy. The evolution of the shape of the C Kα emission band of highly oriented pyrolytic graphite (HOPG), as a function of the angle between the emission direction and the (0 0 0 1) planes, is measured. These results, compared to those with a grating, demonstrate that the achieved spectral resolution enables disentangling σ → 1s and π → 1s transitions within the C K emission band.

scholarly journals High spectral resolution x-ray optics with highly oriented pyrolytic graphite

2006 ◽  
Vol 14 (10) ◽  
pp. 4570 ◽  
Author(s):  
H. Legall ◽  
H. Stiel ◽  
V. Arkadiev ◽  
A. A. Bjeoumikhov
Keyword(s):  
Spectral Resolution ◽  
Pyrolytic Graphite ◽  
High Spectral Resolution ◽  
Highly Oriented Pyrolytic Graphite ◽  
Ray Optics ◽  
X Ray

scholarly journals Investigation of laser-produced chlorine plasma radiation for non-monochromatic X-ray scattering experiments

2006 ◽  
Vol 24 (3) ◽  
pp. 335-345 ◽  
Author(s):  
M. SCHOLLMEIER ◽  
G. RODRÍGUEZ PRIETO ◽  
F.B. ROSMEJ ◽  
G. SCHAUMANN ◽  
A. BLAZEVIC ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Pyrolytic Graphite ◽  
Line Emission ◽  
Plasma Radiation ◽  
High Spectral Resolution ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Dense Plasmas ◽  
X Ray Scattering ◽  
Ray Scattering

The chlorine Heαradiation of polyvinyl chloride (PVC) was investigated with respect to X-ray scattering experiments on dense plasmas. The X-ray source was a laser-produced plasma that was observed with a highly reflective highly oriented pyrolytic graphite (HOPG) crystal spectrometer as it is used in current x-ray scattering experiments on dense plasmas. The underlying dielectronic satellites of Heαcannot be resolved, therefore the plasma was observed at the same time with a focusing spectrometer with spatial resolution. To reconstruct the spectrum a simple model to calculate the spectral line emission based on dielectronic recombination and inner shell excitation of helium- and lithium-like ions was used. The analysis shows that chlorine dielectronic satellite emission is intense compared to Heαin laser-produced chlorine plasmas with a temperature of 300 eV in this wavelength range of Δλ = 0.07 Å (ΔE= 43 eV). The method proposed in this paper allows deducing experimentally the role of the underlying dielectronic satellites in the scatter spectrum measured with a HOPG crystal spectrometer. It is shown that the dielectronic satellites can be neglected when the scattering is measured with low spectral resolution in the non-collective regime. They are of major importance in the collective scatter regime where a high spectral resolution is necessary.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

scholarly journals Possible Pitfalls in the Analysis of Minerals and Loose Materials by Portable XRF, and How to Overcome Them

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laboratory Data ◽  
Data Sets ◽  
Light Elements ◽  
Portable Xrf ◽  
X Ray ◽  
Protective Films ◽  
The Matrix ◽  
Valuable Complement ◽  
Physical Effects

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.

Improvement of the Detection Sensitivity of Edxrf Trace Element Analysis by Means of Efficient X-Ray Focusing Based on Strongly Curved Hopg Crystals

1995 ◽  
Vol 39 ◽  
pp. 109-117
Author(s):  
Burkhard Beckhoff ◽  
Birgit Kanngießer
Keyword(s):  
High Intensity ◽  
Focal Plane ◽  
Bragg Reflection ◽  
Pyrolytic Graphite ◽  
Trace Element Analysis ◽  
Detection Sensitivity ◽  
Element Analysis ◽  
X Ray ◽  
Wide Range ◽  
Very High

X-ray focusing based on Bragg reflection at curved crystals allows collection of a large solid angle of incident radiation, monochromatization of this radiation, and condensation of the beam reflected at the crystal into a small spatial cross-section in a pre-selected focal plane. Thus, for the Bragg reflected radiation, one can achieve higher intensities than for the radiation passing directly to the same small area in the focal plane. In that case one can profit considerably from X-ray focusing in an EDXRF arrangement. The 00 2 reflection at Highly Oriented Pyrolytic Graphite (HOPG) crystals offers a very high intensity of the Bragg reflected beam for a wide range of photon energies. Furthermore, curvature radii smaller than 10 mm can be achieved for HOPG crystals ensuring efficient X-ray focusing in EDXRF applications. For the trace analysis of very small amounts of specimen material deposited on small areas of thin-filter backings, HOPG based X-ray focusing may be used to achieve a very high intensity of monochromatic excitation radiation.

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