scholarly journals The dust-scattering component of X-ray extinction: effects on continuum fitting and high-resolution absorption edge structure

2016 ◽  
Vol 458 (2) ◽  
pp. 1345-1351 ◽  
Author(s):  
L. R. Corrales ◽  
J. García ◽  
J. Wilms ◽  
F. Baganoff
Keyword(s):  
High Resolution ◽  
Absorption Edge ◽  
Edge Structure ◽  
X Ray

IN-VIVO ELEMENTAL ANALYSIS BY PIXE-μ-CT

2007 ◽  
Vol 17 (01n02) ◽  
pp. 41-46 ◽  
Author(s):  
Y. KAWAMURA ◽  
K. ISHII ◽  
H. YAMAZAKI ◽  
S. MATSUYAMA ◽  
Y. KIKUCHI ◽  
...  
Keyword(s):  
High Resolution ◽  
Absorption Edge ◽  
Ion Beam ◽  
Projection Data ◽  
Elemental Distribution ◽  
X Rays ◽  
Ct Reconstruction ◽  
3D Images ◽  
X Ray

We have developed “micron-CT”, using micro-PIXE for in-vivo imaging. This system comprises an X-ray CCD camera (Hamamatsu photonics C8800X9) with high resolution (pixel size: 8×8 μm 2, number of pixels: 1000×1000) and an X-ray-point-source with a spot size of 1.5×1.5 μm 2 which is generated by irradiation of a microbeam on a pure metal target. Thus we can acquire projection data with high resolution. The sample is placed in a small diameter tube and is rotated by a stepping motor. The 3D images were reconstructed from the obtained projection data by using cone-beam CT reconstruction algorithm. X-ray spectra produced by heavy charged particle bombardment, exhibit a much smaller continuous background compared to electron bombardment. Therefore, X-rays produced by ion beam can be used as a monochromatic and low energy X-ray source. The feature is very effective to investigate small insects. Moreover we can get elemental distribution image of object by choosing appropriate characteristic X-rays corresponding to the absorption edge. On the other hand, the conventional X-ray CT, in which continuous X-rays are used, provides images of the electron density in the object. Using this system, we were able to get 3D images of a living ant's head with 6 μm spatial resolution. By using Fe - K -X-rays (6.40 keV) and Co - K -X-rays (6.93 keV), we can investigate the 3D distribution of Mn ( K -absorption edge = 6.54 keV) in an ant's head.

scholarly journals Probing X-ray Emitting Plasma with High Resolution Chandra and XMM-Newton Spectra

2005 ◽  
Vol 13 ◽  
pp. 618-621
Author(s):  
Julia C. Lee
Keyword(s):  
High Resolution ◽  
Atomic Physics ◽  
Theoretical Calculations ◽  
Atomic Data ◽  
Experimental Measurements ◽  
Edge Structure ◽  
X Ray

AbstractHighlights of interesting astrophysical discoveries are reviewed in the context of high resolution X-ray spectroscopy made possible with Chandra and XMM-Newton, and its relevance to atomic physics calculations and measurements is discussed. These spectra have shown that the overlap between astrophysics and atomic physics is stronger than ever, as discoveries of new X-ray lines and edge structure is matching the need for increasingly detailed theoretical calculations and experimental measurements of atomic data.

scholarly journals A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

2014 ◽  
Vol 85 (11) ◽  
pp. 113906 ◽  
Author(s):  
G. T. Seidler ◽  
D. R. Mortensen ◽  
A. J. Remesnik ◽  
J. I. Pacold ◽  
N. A. Ball ◽  
...  
Keyword(s):  
High Resolution ◽  
Emission Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

scholarly journals A Rebirth of Laboratory XANES and XES

2014 ◽  
Vol 70 (a1) ◽  
pp. C222-C222
Author(s):  
Gerald Seidler ◽  
Devon Mortensen ◽  
Joseph Pacold ◽  
Oliver Hoidn
Keyword(s):  
High Resolution ◽  
Energy Range ◽  
Emission Spectroscopy ◽  
Light Sources ◽  
Edge Structure ◽  
X Ray ◽  
Insertion Device ◽  
Synchrotron Light ◽  
Synchrotron Light Sources ◽  
X Ray Absorption

We have recently launched a reinvestigation of laboratory-based measurement of x-ray absorption near edge structure (XANES) and high-resolution x-ray emission spectroscopy (XES). Driven by the roughly one-hundred-fold improvement in the efficiency of high resolution x-ray optics compared to the 1970's, we have demonstrated that surprisingly impressive performance is now possible with laboratory XES instruments and that quite useful performance is possible for laboratory XANES. For applications in the 5 keV- 10 keV energy range, i.e., appropriate for 3d transition metal K edges and lanthanide L edges, we find XES performance that is intermediate between what can be achieved at bending-magnet and insertion-device beamlines at third generation synchrotron light sources. In the same energy range, we find that high quality XANES measurements can be performed in transmission mode on concentrated samples with the present instrument and should be possible, in many cases, in fluorescence mode after a planned upgrade brings the monochromatic beam flux up to approximately 10M/sec.

INTERMEDIATE VALENCE IN Sm1−xLaxSe ALLOYS: X-RAY ABSORPTION AND LATTICE PARAMETER STUDIES

1990 ◽  
Vol 04 (10) ◽  
pp. 1707-1716 ◽  
Author(s):  
R.K. SINGHAL ◽  
U. CHANDRA ◽  
K.B. GARG ◽  
D.C. JAIN ◽  
H.S. CHAUHAN
Keyword(s):  
Absorption Edge ◽  
Direct Evidence ◽  
Lattice Parameter ◽  
Trivalent Cation ◽  
Intermediate Valence ◽  
Valence Transition ◽  
Edge Structure ◽  
X Ray ◽  
Average Valence ◽  
X Ray Absorption

X-ray absorption near edge structure (XANES) measurements on LIII absorption edge of Sm are employed to study the intermediate valence in Sm 1−x La x Se (x=0.08, 0.10, 0.15 and 0.25) alloys wherein the substitution of the trivalent cation, La 3a+, for Sm 2+ drives the latter to a higher valence state from divalent towards trivalent in the SmSe lattice. Two absorption peaks corresponding to two different valent states of Sm provide direct evidence for intermediate valence of Sm in these alloys. The split white lines at the L III edge of Sm are used to determine the Sm mean valence in the alloys. Average valence data deduced from Sm L III edge XANES shows a continuous valence transition with increasing La concentration. Lattice parameters for these alloys measured by XRD also show a regular decrease with La concentration showing an agreement with the XANES results.

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