Modeling, Analysis and Performance Evaluations of Phantom Positioning by Using kV X-ray Imaging, CBCT, and IR Camera

We consider the problem of dynamically allocating screening resources of different efficacies (e.g., magnetic or X-ray imaging) at checkpoints (e.g., at airports or ports) to successfully avert an attack by one of the screenees. Previously, the Threat Screening Game model was introduced to address this problem under the assumption that screenee arrival times are perfectly known. In reality, arrival times are uncertain, which severely impedes the implementability and performance of this approach. We thus propose a novel framework for dynamic allocation of threat screening resources that explicitly accounts for uncertainty in the screenee arrival times. We model the problem as a multistage robust optimization problem and propose a tractable solution approach using compact linear decision rules combined with robust reformulation and constraint randomization. We perform extensive numerical experiments which showcase that our approach outperforms (a) exact solution methods in terms of tractability, while incurring only a very minor loss in optimality, and (b) methods that ignore uncertainty in terms of both feasibility and optimality.

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A phase-retrieval toolbox for X-ray holography and tomography

Journal of Synchrotron Radiation ◽

10.1107/s1600577520002398 ◽

2020 ◽

Vol 27 (3) ◽

pp. 852-859 ◽

Cited By ~ 9

Author(s):

Leon M. Lohse ◽

Anna-Lena Robisch ◽

Mareike Töpperwien ◽

Simon Maretzke ◽

Martin Krenkel ◽

...

Keyword(s):

Phase Contrast ◽

Phase Retrieval ◽

Performance Test ◽

Limiting Factor ◽

Full Field ◽

X Ray ◽

X Ray Imaging ◽

Wide Range ◽

Experimental Parameters ◽

And Performance

Propagation-based phase-contrast X-ray imaging is by now a well established imaging technique, which – as a full-field technique – is particularly useful for tomography applications. Since it can be implemented with synchrotron radiation and at laboratory micro-focus sources, it covers a wide range of applications. A limiting factor in its development has been the phase-retrieval step, which was often performed using methods with a limited regime of applicability, typically based on linearization. In this work, a much larger set of algorithms, which covers a wide range of cases (experimental parameters, objects and constraints), is compiled into a single toolbox – the HoloTomoToolbox – which is made publicly available. Importantly, the unified structure of the implemented phase-retrieval functions facilitates their use and performance test on different experimental data.

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Electron beam range effects in SEM/EDX: Application to scratch-testing of coated carbides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127281 ◽

1987 ◽

Vol 45 ◽

pp. 544-545

Author(s):

J. Hefter

Keyword(s):

Electron Beam ◽

Protective Coatings ◽

Cutting Tools ◽

Scratch Test ◽

Pixel Resolution ◽

X Ray ◽

X Ray Imaging ◽

Test Investigation ◽

And Performance ◽

Tool Technology

The use of protective coatings to enhance the chemical and mechanical properties of materials is widely practiced in industry. For example, in cutting tool technology, the use of strongly adhering, specialized coatings has expanded the lifetime and performance of cutting tools. The most widely used technique for checking coating adherence is the scratch-test. Investigation of the scratch regions by SEM via both electron and x-ray imaging may assist in the determination of the failure mode region, i.e., within the coating, at an interface, or within the substrate.As an example of this approach, a cemented carbide was coated first with TiC (6 μm) and then with Al2O3 (2 μm). A scratch-test was carried out and the sample was analyzed using the JEOL JSM-840 analytical SEM at an electron beam energy of 20 keV. All secondary electron (grayscale) and x-ray images (256x256x8 pixel resolution) were taken using digital imaging hardware on a Tracor Northern TN-5500 system.

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The clinical feasibility and performance of an orthogonal X-ray imaging system for image-guided radiotherapy in nasopharyngeal cancer patients: Comparison with cone-beam CT

Physica Medica ◽

10.1016/j.ejmp.2015.11.010 ◽

2016 ◽

Vol 32 (1) ◽

pp. 266-271 ◽

Cited By ~ 3

Author(s):

Li-Rong Zhao ◽

Yi-Bing Zhou ◽

Guang-Hui Li ◽

Qi-Ming Li ◽

Ding-Qiang Yang ◽

...

Keyword(s):

Cancer Patients ◽

Imaging System ◽

Cone Beam Ct ◽

Nasopharyngeal Cancer ◽

Cone Beam ◽

Image Guided Radiotherapy ◽

X Ray ◽

Image Guided ◽

X Ray Imaging ◽

And Performance

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EUV Astrophysics with ALEXIS: The Wide View

International Astronomical Union Colloquium ◽

10.1017/s0252921100035685 ◽

1996 ◽

Vol 152 ◽

pp. 7-14

Author(s):

Jeffrey Bloch

Keyword(s):

Low Cost ◽

Rapid Development ◽

Normal Incidence ◽

Space Mission ◽

Los Alamos ◽

X Ray ◽

Ground Station ◽

X Ray Imaging ◽

And Performance ◽

Imaging Sensors

The Array of Low Energy X-ray Imaging Sensors (ALEXIS) satellite is Los Alamos’ pathfinding small space mission achieving low cost and rapid development time for its technology demonstration and science goals. The ALEXIS satellite contains the ALEXIS telescope array, which consists of six EUV/ultrasoft X-ray telescopes utilizing normal incidence multilayer mirrors, microchannel plate detectors, and thin UV rejecting filters. Each telescope is tuned to a relatively narrow bandpass centered at either 130, 171, or 186 angstroms. Each telescope has a 33° field-of-view, and a resolution of ~ 0.25°. With each 50 s rotation of the satellite, the telescopes scan most of the anti-solar hemisphere of the sky. The spacecraft is controlled exclusively from a ground station located at Los Alamos.This paper discusses the characteristics and performance of the ALEXIS telescopes and the results from the mission in spite of the damage incurred to the spacecraft at launch.

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Thermal design and performance of the REgolith x-ray imaging spectrometer (REXIS) instrument

10.1117/12.2054995 ◽

2014 ◽

Cited By ~ 2

Author(s):

Kevin D. Stout ◽

Rebecca A. Masterson

Keyword(s):

Thermal Design ◽

Imaging Spectrometer ◽

X Ray ◽

X Ray Imaging ◽

And Performance

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Calibration and performance of the Energetic X-ray Imaging Telescope Experiment

IEEE Transactions on Nuclear Science ◽

10.1109/23.34568 ◽

1989 ◽

Vol 36 (1) ◽

pp. 871-875 ◽

Cited By ~ 9

Author(s):

J. Braga ◽

C.E. Covault ◽

J.E. Grindlay

Keyword(s):

X Ray ◽

X Ray Imaging ◽

Imaging Telescope ◽

And Performance

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Visibility of Polychromatic Grating-Based X-Ray Imaging Systems Based on Wave-Optical Theories and Frequency Domain Analysis

Frontiers in Physics ◽

10.3389/fphy.2021.630337 ◽

2021 ◽

Vol 9 ◽

Author(s):

Xiaohua Zhu ◽

Chengpeng Wu ◽

Hewei Gao ◽

Xi Zhang ◽

Li Zhang

Keyword(s):

Analytical Form ◽

Frequency Domain Analysis ◽

Real Space ◽

Optical Simulation ◽

Contrast Imaging ◽

X Ray ◽

Design And Optimization ◽

X Ray Imaging ◽

And Performance ◽

Relationship Of

Grating-based X-ray phase-contrast imaging and tomography, applicable with traditional polychromatic X-ray tubes, have shown great potential for future applications of imaging with multimodal information indicating materials and microstructures simultaneously. The parameters and performance of the grating system could be simulated by a wave-optical simulation framework and proved feasible for the design and optimization of both coherent and incoherent gratings systems. However, the simulation involves real-space point-wise calculation of the Fourier transformation, and the direct expression of the relationship of the parameters was absent. In this work, we analyzed the Fourier domain characteristics of the simulated system and the presented visibility of the system of different energies in an analytical form. The derived direct expression which omitted the simulation process was validated with results of both simulation and real experiments and may help future designs, optimizations and studies of the energy-resolved characteristics of the system.

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