Bent crystals by surface grooving method for high-efficiency concentration of hard x-ray photons by a Laue lens

The efficiency of a Laue lens for X- and γ-ray focusing in the energy range 60–600 keV is closely linked to the diffraction efficiency of the single crystals composing the lens. A powerful focusing system is crucial for applications like medical imaging and X-ray astronomy where wide beams must be focused. Mosaic crystals with a high density, such as Cu or Au, and bent crystals with curved diffracting planes (CDPs) are considered for the realization of a focusing system for γ-rays, owing to their high diffraction efficiency in a predetermined angular range. In this work, a comparison of the efficiency of CDP crystals and Cu and Au mosaic crystals was performed on the basis of the theory of X-ray diffraction. Si, GaAs and Ge CDP crystals with optimized thicknesses and moderate radii of curvature of several tens of metres demonstrate comparable or superior performance with respect to the higher atomic number mosaic crystals generally used. In order to increase the efficiency of the lens further, a stack of several CDP crystals is proposed as an optical element. CDP crystals were obtained by a surface-damage method, and a stack of two surface-damaged bent Si crystals was prepared and tested. Rocking curves of the stack were performed with synchrotron radiation at 19 keV to check the lattice alignment: they exhibited only one diffraction peak.

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High-efficiency focusing of hard X-rays exploiting the quasi-mosaic effect in a bent germanium crystal

Journal of Applied Crystallography ◽

10.1107/s1600576714005056 ◽

2014 ◽

Vol 47 (2) ◽

pp. 799-802 ◽

Cited By ~ 8

Author(s):

Riccardo Camattari ◽

Gianfranco Paternò ◽

Alessandro Battelli ◽

Valerio Bellucci ◽

Pierre Bastie ◽

...

Keyword(s):

High Efficiency ◽

Sample Surface ◽

Mechanical Anisotropy ◽

X Rays ◽

Germanium Crystal ◽

Optical Components ◽

X Ray ◽

Laue Lens ◽

Γ Rays ◽

Laue Geometry

A germanium crystal was bent through a grid of superficial grooves, manufactured on the sample surface. The resulting diffraction planes were bent thanks to quasi-mosaicity, which is an effect of mechanical anisotropy in crystals. High integrated diffraction efficiency was achieved in symmetric Laue geometry with a monochromatic X-ray beam set at 150 and 300 keV. It is demonstrated that the sample is capable of efficiently focusing X-rays. Such crystals can be used as optical components to focalize X- and γ-rays in a high-resolution Laue lens.

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Complete Ring Artifacts Reduction Procedure for Lab-Based X-ray Nano CT Systems

Sensors ◽

10.3390/s21010238 ◽

2021 ◽

Vol 21 (1) ◽

pp. 238

Author(s):

Jakub Šalplachta ◽

Tomáš Zikmund ◽

Marek Zemek ◽

Adam Břínek ◽

Yoshihiro Takeda ◽

...

Keyword(s):

High Efficiency ◽

Image Inpainting ◽

Simulated Data ◽

Complementary Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Detection Accuracy ◽

Reduction Procedure ◽

X Ray ◽

Artifacts Reduction ◽

Ct Data

In this article, we introduce a new ring artifacts reduction procedure that combines several ideas from existing methods into one complex and robust approach with a goal to overcome their individual weaknesses and limitations. The procedure differentiates two types of ring artifacts according to their cause and character in computed tomography (CT) data. Each type is then addressed separately in the sinogram domain. The novel iterative schemes based on relative total variations (RTV) were integrated to detect the artifacts. The correction process uses the image inpainting, and the intensity deviations smoothing method. The procedure was implemented in scope of lab-based X-ray nano CT with detection systems based on charge-coupled device (CCD) and scientific complementary metal–oxide–semiconductor (sCMOS) technologies. The procedure was then further tested and optimized on the simulated data and the real CT data of selected samples with different compositions. The performance of the procedure was quantitatively evaluated in terms of the artifacts’ detection accuracy, the comparison with existing methods, and the ability to preserve spatial resolution. The results show a high efficiency of ring removal and the preservation of the original sample’s structure.

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Monte Carlo Modeling and Design of Photon Energy Attenuation Layers for >10× Quantum Yield Enhancement in Si-Based Hard X-ray Detectors

Instruments ◽

10.3390/instruments5020017 ◽

2021 ◽

Vol 5 (2) ◽

pp. 17

Author(s):

Eldred Lee ◽

Kaitlin M. Anagnost ◽

Zhehui Wang ◽

Michael R. James ◽

Eric R. Fossum ◽

...

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Quantum Yield ◽

Photon Energy ◽

High Efficiency ◽

High Energy ◽

Yield Enhancement ◽

X Ray ◽

Simulation Results ◽

Conversion Efficiencies

High-energy (>20 keV) X-ray photon detection at high quantum yield, high spatial resolution, and short response time has long been an important area of study in physics. Scintillation is a prevalent method but limited in various ways. Directly detecting high-energy X-ray photons has been a challenge to this day, mainly due to low photon-to-photoelectron conversion efficiencies. Commercially available state-of-the-art Si direct detection products such as the Si charge-coupled device (CCD) are inefficient for >10 keV photons. Here, we present Monte Carlo simulation results and analyses to introduce a highly effective yet simple high-energy X-ray detection concept with significantly enhanced photon-to-electron conversion efficiencies composed of two layers: a top high-Z photon energy attenuation layer (PAL) and a bottom Si detector. We use the principle of photon energy down conversion, where high-energy X-ray photon energies are attenuated down to ≤10 keV via inelastic scattering suitable for efficient photoelectric absorption by Si. Our Monte Carlo simulation results demonstrate that a 10–30× increase in quantum yield can be achieved using PbTe PAL on Si, potentially advancing high-resolution, high-efficiency X-ray detection using PAL-enhanced Si CMOS image sensors.

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Holographic x-ray detection: A method for high resolution, high efficiency x-ray detection with differential phase contrast

Applied Physics Letters ◽

10.1063/5.0053357 ◽

2021 ◽

Vol 118 (26) ◽

pp. 261105

Author(s):

G. K. Herring ◽

L. Hesselink

Keyword(s):

High Resolution ◽

Phase Contrast ◽

High Efficiency ◽

X Ray ◽

Differential Phase ◽

Differential Phase Contrast

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Combination of Dual-Energy X-ray Transmission and Variable Gas-Ejection for the In-Line Automatic Sorting of Many Types of Scrap in One Measurement

Applied Sciences ◽

10.3390/app11104349 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4349

Author(s):

Tianzhong Xiong ◽

Wenhua Ye ◽

Xiang Xu

Keyword(s):

High Efficiency ◽

Nearest Neighbor ◽

High Energy ◽

Dual Energy ◽

Center Of Gravity ◽

Low Energy ◽

Identification Accuracy ◽

Flow Process ◽

X Ray ◽

Automatic Sorting

As an important part of pretreatment before recycling, sorting has a great impact on the quality, efficiency, cost and difficulty of recycling. In this paper, dual-energy X-ray transmission (DE-XRT) combined with variable gas-ejection is used to improve the quality and efficiency of in-line automatic sorting of waste non-ferrous metals. A method was proposed to judge the sorting ability, identify the types, and calculate the mass and center-of-gravity coordinates according to the shading of low-energy, the line scan direction coordinate and transparency natural logarithm ratio of low energy to high energy (R_value). The material identification was satisfied by the nearest neighbor algorithm of effective points in the material range to the R_value calibration surface. The flow-process of identification was also presented. Based on the thickness of the calibration surface, the material mass and center-of-gravity coordinates were calculated. The feasibility of controlling material falling points by variable gas-ejection was analyzed. The experimental verification of self-made materials showed that identification accuracy by count basis was 85%, mass and center-of-gravity coordinates calculation errors were both below 5%. The method proposed features high accuracy, high efficiency, and low operation cost and is of great application value even to other solid waste sorting, such as plastics, glass and ceramics.

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