C-11 Invited—Low-Power Monochromatic Focused Beam XRF Systems Using Doubly Curved Crystals

2007 ◽  
Vol 22 (2) ◽  
pp. 188-188
Author(s):  
Z. W. Chen ◽  
F. Wei ◽  
B. Beumer ◽  
D. Li ◽  
W. M. Gibson
Keyword(s):  
Low Power ◽  
Doubly Curved ◽  
Doubly Curved Crystals ◽  
Focused Beam

Doubly curved crystal (DCC) X-ray optics and applications

2002 ◽  
Vol 17 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Zewu Chen ◽  
Walter M. Gibson
Keyword(s):  
Thin Films ◽  
Low Power ◽  
X Rays ◽  
Enabling Technology ◽  
Ray Optics ◽  
X Ray ◽  
Composition And Structure ◽  
Composition Structure ◽  
Doubly Curved

Doubly curved crystal (DCC) X-ray optics provide an enabling technology for new portable, remote, and in situ applications of monochromatic X-rays for composition and structure analysis of amorphous, polycrystalline, and crystalline solids. Femtogram sensitivity for surface contamination, parts-per-billion (ppb) impurity levels for solids, and composition, structure and uniformity of thin films with compact, low power (20–50 W) source optic combinations are possible.

Source misalignment effects on crystal collection solid angle and intensity profile

2012 ◽  
Vol 45 (5) ◽  
pp. 890-901 ◽  
Author(s):  
Sayyed Jalal Pestehe ◽  
Golamreza Askari Germi
Keyword(s):  
Crystal Surface ◽  
Solid Angle ◽  
Intensity Profile ◽  
Bragg Angle ◽  
Angular Deviation ◽  
X Ray ◽  
Trial And Error Method ◽  
General Relations ◽  
Doubly Curved ◽  
Doubly Curved Crystals

The X-ray optics of singly and doubly curved crystals are studied using a vector procedure and rotation matrices and general relations for the angular deviation from the Bragg angle over the crystal surface with a source aligned or misaligned on the Rowland circle. Hence, the effective scattering area, collection solid angle and diffracted X-ray intensity profile on the crystal surface are derived. The effective areas and the diffracted X-ray intensity profiles on the crystal surface for both aligned and misaligned source cases are plotted and compared. It is argued that the introduced point-focusing crystal configuration confirms the radii that have been obtained previously by a trial and error method by optimizing the crystal collection solid angle.

Analysis of focused-beam powder X-ray diffraction resolution using doubly curved crystal optics

2009 ◽  
Vol 42 (4) ◽  
pp. 715-723 ◽  
Author(s):  
A. Bingölbali ◽  
C. A. MacDonald
Keyword(s):  
Monte Carlo Model ◽  
Geometric Analysis ◽  
Peak Width ◽  
Detector Resolution ◽  
X Ray ◽  
Area Detector ◽  
Intensity Measurements ◽  
Ring Shape ◽  
Doubly Curved ◽  
Focused Beam

In this work, focusing doubly curved crystal X-ray optics were used in powder diffraction to produce an intense spot for use with small powder or polycrystalline samples. Measurements of several standard small inorganic samples were made using a low-power microfocus source. Diffracted peak width, resolution and intensity were analyzed. The measured resolution, defined as the uncertainty in the peak center, was much smaller than the peak width, which was broadened owing to the use of a focused beam. Resolution was limited by the pixel size of the area detector. Resolution and intensity measurements were in good agreement with those obtained from simple geometric analysis and from a Monte Carlo model used to simulate the diffraction ring shape and width.

X‐ray focusing optics. I. Applications of wave optics to doubly curved crystals with a point x‐ray source

1995 ◽  
Vol 77 (5) ◽  
pp. 1843-1848 ◽  
Author(s):  
F. N. Chukhovskii ◽  
W. Z. Chang ◽  
E. Förster
Keyword(s):  
Wave Optics ◽  
X Ray ◽  
Doubly Curved ◽  
Doubly Curved Crystals
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