Confocal X-ray Fluorescence (XRF) Microscopy: A New Technique for the Nondestructive Compositional Depth Profiling of Paintings

2004 ◽  
Vol 852 ◽  
Author(s):  
Arthur R. Woll ◽  
Donald H. Bilderback ◽  
Sol Gruner ◽  
Ning Gao ◽  
Rong Huang ◽  
...  
Keyword(s):  
Depth Profiling ◽  
Incident Beam ◽  
High Energy ◽  
X Rays ◽  
Oil Painting ◽  
Synchrotron Source ◽  
X Ray ◽  
Glass Slides ◽  
A New Technique ◽  
Paint Films

ABSTRACTA confocal x-ray fluorescence microscope was built at the Cornell High Energy Synchrotron Source (CHESS) to determine the composition of buried paint layers that range from 10–80 μm thick in paintings. The microscope consists of a borosilicate monocapillary optic to focus the incident beam and a borosilicate polycapillary lens to collect the fluorescent x-rays. The overlap of the two focal regions is several tens of microns in extent, and defines the active, or confocal, volume of the microscope. The capabilities of the technique were tested using acrylic paint films with distinct layers brushed onto glass slides and a twentieth century oil painting on canvas. The position and thickness of individual layers were extracted from their fluorescence profiles by fitting to a simple, semi-empirical model.

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 Design and Performance of the X-ray Polarimeter X-Calibur

2014 ◽  
Vol 03 (02) ◽  
pp. 1440008 ◽  
Author(s):  
M. Beilicke ◽  
F. Kislat ◽  
A. Zajczyk ◽  
Q. Guo ◽  
R. Endsley ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection Efficiency ◽  
Grazing Incidence ◽  
High Energy ◽  
X Rays ◽  
Field Orientation ◽  
Synchrotron Source ◽  
X Ray ◽  
And Performance ◽  
Detector Assembly

X-ray polarimetry promises to give qualitatively new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, neutron stars, and gamma-ray bursts. We designed, built and tested a X-ray polarimeter, X-Calibur, to be used in the focal plane of the balloon-borne InFOCμS grazing incidence X-ray telescope. X-Calibur combines a low-Z scatterer with a Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 20–80 keV X-rays making use of the fact that polarized photons scatter preferentially perpendicular to the electric field orientation. X-Calibur achieves a high detection efficiency of ≃80%. The X-Calibur detector assembly is completed, tested, and fully calibrated. The response to a polarized X-ray beam was measured successfully at the Cornell High Energy Synchrotron Source. This paper describes the design, calibration and performance of the X-Calibur polarimeter. In principle, a similar space-borne scattering polarimeter could operate over the broader 2–100 keV energy band.

Angle-Resolved X-Ray Depth Profiling: Interpretation of Angleresolved Profiles Using a Monte Carlo Approach

1999 ◽  
Vol 5 (S2) ◽  
pp. 582-583
Author(s):  
D.K. Wilkinson ◽  
M. Prutton ◽  
D.A. Loveday
Keyword(s):  
Monte Carlo ◽  
Electron Scattering ◽  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Incident Beam ◽  
Angle Of Incidence ◽  
X Rays ◽  
X Ray ◽  
Interaction Volume ◽  
Depth Profiles

A technique has been developed for the interpretation of composition depth profiles from angleresolved x-ray data using a Monte Carlo electron scattering simulation. Conventional methods for the interpretation of angle-resolved depth profiles used in the fields of x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) assume that the outgoing signal is exponentially attenuated along its path. This assumption if not valid for angle-resolved x-ray techniques, as the x-ray signal is dependent on both the paths of the incident electrons and the path of the emitted x-rays. In this case, while the latter can be treated using an exponential attenuation, the path of the incident beam is more complex and corresponds to the well known “pear-shaped” interaction volume. In order to reliably interpret angle-resolved depth profiles in which the angle of the incident beam is varied, it is necessary to be able to obtain the distribution of x-ray emission within the sample for any angle of incidence.

scholarly journals Pixelated transmission-mode diamond X-ray detector

2015 ◽  
Vol 22 (6) ◽  
pp. 1396-1402 ◽  
Author(s):  
Tianyi Zhou ◽  
Wenxiang Ding ◽  
Mengjia Gaowei ◽  
Gianluigi De Geronimo ◽  
Jen Bohon ◽  
...  
Keyword(s):  
Single Channel ◽  
Sampling Rate ◽  
Incident Beam ◽  
Chemical Vapor ◽  
High Energy ◽  
Transmission Mode ◽  
Beam Position ◽  
Synchrotron Source ◽  
X Ray ◽  
Single Crystal Diamond

Fabrication and testing of a prototype transmission-mode pixelated diamond X-ray detector (pitch size 60–100 µm), designed to simultaneously measure the flux, position and morphology of an X-ray beam in real time, are described. The pixel density is achieved by lithographically patterning vertical stripes on the front and horizontal stripes on the back of an electronic-grade chemical vapor deposition single-crystal diamond. The bias is rotated through the back horizontal stripes and the current is read out on the front vertical stripes at a rate of ∼1 kHz, which leads to an image sampling rate of ∼30 Hz. This novel signal readout scheme was tested at beamline X28C at the National Synchrotron Light Source (white beam, 5–15 keV) and at beamline G3 at the Cornell High Energy Synchrotron Source (monochromatic beam, 11.3 keV) with incident beam flux ranges from 1.8 × 10−2to 90 W mm−2. Test results show that the novel detector provides precise beam position (positional noise within 1%) and morphology information (error within 2%), with an additional software-controlled single channel mode providing accurate flux measurement (fluctuation within 1%).

scholarly journals An X-ray Spectral Survey of BL Lac Objects

1989 ◽  
Vol 134 ◽  
pp. 191-193 ◽  
Author(s):  
P. Barr ◽  
P. Giommi ◽  
A. Pollock ◽  
G. Tagliaferri ◽  
D. Maccagni ◽  
...  
Keyword(s):  
High Energy ◽  
Oxygen Absorption ◽  
X Rays ◽  
Bl Lac Objects ◽  
Synchrotron Source ◽  
X Ray ◽  
High Energy Tail ◽  
Bl Lac ◽  
Spectral Survey ◽  
Bl Lacs

A wide variety of X-ray spectral forms has been reported in BL Lac objects. Concave spectra, i.e. a steep soft X-ray spectrum with a flat high energy tail, have been reported in a few of the brightest BL Lacs (e.g Urry 1986). Conversely, convex spectra (steep hard X-rays, flat soft X-ray spectrum) have also been reported, sometimes in the same objects (Madejski 1985, Barr et al 1988, George et al 1988). The high energy tails have usually been invoked as a signature of synchrotron-self-Compton emission. Two conflicting interpretations of the convex spectra have been made. Urry et al (1986) suggest absorption by a partially ionised medium, probably intrinsic to the BL Lac object, following the identification of an Oxygen absorption trough in the Einstein OGS spectrum of PKS 2155-304 by Canizares and Kruper (1984). Conversely, Barr et al (1988) attribute the hard X-ray steepening to energy loss mechanisms operating on a synchrotron source.

Side-bounce beamlines using single-reflection diamond monochromators at Cornell High Energy Synchrotron Source

2021 ◽  
Vol 28 (2) ◽  
pp. 429-438
Author(s):  
Stanislav Stoupin ◽  
Thomas Krawczyk ◽  
David Sagan ◽  
Alexander Temnykh ◽  
Louisa Smieska ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Functional Materials ◽  
Soft Materials ◽  
High Energy ◽  
Bragg Angle ◽  
Chemical Vapor Deposition Method ◽  
X Rays ◽  
Time Resolved ◽  
Synchrotron Source ◽  
X Ray

The design and implementation of new beamlines featuring side-bounce (single-reflection) diamond monochromators at Cornell High Energy Synchrotron Source (CHESS) are described. Undulator radiation is monochromated using an interchangeable set of diamond crystal plates reflecting radiation in the horizontal (synchrotron) plane, where each crystal plate is set to one of the low-index Bragg reflections (111, 220, 311 and 400) in either Bragg or Laue reflection geometries. At the nominal Bragg angle of 18° these reflections deliver monochromated X-rays with photon energies of 9.7, 15.9, 18.65 and 22.5 keV, respectively. An X-ray mirror downstream of the diamond monochromator is used for rejection of higher radiation harmonics and for initial focusing of the monochromated beam. The characteristics of the X-ray beam entering the experimental station were measured experimentally and compared with the results of simulations. A reasonable agreement is demonstrated. It is shown that the use of selected high-dislocation-density `mosaic' diamond single-crystal plates produced using the chemical vapor deposition method yields a few-fold enhancement in the flux density of the monochromated beam in comparison with that delivered by perfect crystals under the same conditions. At present, the Functional Materials Beamline at CHESS, which is used for time-resolved in situ characterization of soft materials during processing, has been outfitted with the described setup.

X-Ray Scattering above 100KeV

1988 ◽  
Vol 143 ◽  
Author(s):  
J. B. Hastings
Keyword(s):  
High Energy ◽  
X Rays ◽  
Synchrotron Source ◽  
X Ray ◽  
High Energies ◽  
X Ray Scattering ◽  
Very High ◽  
Ray Scattering

Conventional x-ray scattering studies have been limited to photon energies (wavelengths) in the 5 to 20 KeV (approx. 2A to 0..5A) regime. With these energies absorption lengths limit the volume of illumination to the first tens of microns of samples. If it were possible to use x-rays of very high energies, true bulk (tens of millimeters) samples could be studied. The availability, intensity and resolution possible with high energies will be discussed and their role in the expanding field of x-ray scattering presented. Preliminary studies at the Cornell High Energy Synchrotron Source (CHESS) will form the basis of these discussions.

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

X-Ray absorption edge elemental imaging of B. thuringienis

1989 ◽  
Vol 47 ◽  
pp. 212-213
Author(s):  
R. L. Stears
Keyword(s):  
Absorption Edge ◽  
Elemental Distribution ◽  
X Rays ◽  
Differential Absorption ◽  
Synchrotron Source ◽  
High Brightness ◽  
X Ray ◽  
Elemental Imaging ◽  
Cellular Integrity ◽  
X Ray Absorption

Because of the nature of the bacterial endospore, little work has been done on analyzing their elemental distribution and composition in the intact, living, hydrated state. The majority of the qualitative analysis entailed intensive disruption and processing of the endospores, which effects their cellular integrity and composition.Absorption edge imaging permits elemental analysis of hydrated, unstained specimens at high resolution. By taking advantage of differential absorption of x-ray photons in regions of varying elemental composition, and using a high brightness, tuneable synchrotron source to obtain monochromatic x-rays, contact x-ray micrographs can be made of unfixed, intact endospores that reveal sites of elemental localization. This study presents new data demonstrating the application of x-ray absorption edge imaging to produce elemental information about nitrogen (N) and calcium (Ca) localization using Bacillus thuringiensis as the test specimen.

scholarly journals Improved Phebus laser performances required for precision laser–target experiments

1998 ◽  
Vol 16 (2) ◽  
pp. 253-265 ◽  
Author(s):  
G. Thiell ◽  
R. Bailly-Salins ◽  
J.L. Bruneau ◽  
G. Coulaud ◽  
P. Estraillier ◽  
...  
Keyword(s):  
Laser Energy ◽  
Incident Beam ◽  
High Energy ◽  
Target Chamber ◽  
Laser Target ◽  
Time Resolved ◽  
X Ray ◽  
Target Experiment ◽  
Pointing Precision ◽  
Energy Shots

The Precision Phebus program, started in 1993, emphasizes a series of laser and target experiment objectives on the two-beam Phebus Nd-phosphate glass laser. Recently, three major objectives that are also very important issues for megajoule-class lasers have been met: First, the balance of the incident beam-to-beam 3ω power is shown to be in the range from 5 to 12% for 3-ns, 3ω-shaped pulses of reproducible high-energy shots; second, the smoothing uniformity of the laser energy deposited on the target, that is, the contrast of the spatial beam modulations, can be kept lower than 5%; and, finally, the tight control of the beam targeting leads to a pointing precision of less than 10 μrd on the target at the target chamber center (TCC) and of 80 μrd on X-ray sources located up to 3 cm from the TCC to improve the space- and time-resolved X-ray shadowgraphy techniques performed for target physics experiments such as implosion and hydrodynamical instability studies.

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