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Characterization of X-ray generator beam profiles

Mitchell, Dean J.; Thompson, Kyle R.; Harding, Lee T.; Thoreson, Gregory G.; Theisen, Lisa A.; Parmeter, John E.

T to compute the radiography properties of various materials, the flux profiles of X-ray sources must be characterized. This report describes the characterization of X-ray beam profiles from a Kimtron industrial 450 kVp radiography system with a Comet MXC-45 HP/11 bipolar oil-cooled X-ray tube. The empirical method described here uses a detector response function to derive photon flux profiles based on data collected with a small cadmium telluride detector. The flux profiles are then reduced to a simple parametric form that enables computation of beam profiles for arbitrary accelerator energies.

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A high-performance and energy-efficient CT reconstruction algorithm for multi-terabyte datasets

IEEE Nuclear Science Symposium Conference Record

Jimenez, Edward S.; Orr, Laurel J.; Thompson, Kyle R.

There has been much work done in implementing various GPU-based Computed Tomography reconstruction algorithms for medical applications showing tremendous improvement in computational performance. While many of these reconstruction algorithms could also be applied to industrial-scale datasets, the performance gains may be modest to non-existent due to a combination of algorithmic, hardware, or scalability limitations. Previous work presented showed an irregular dynamic approach to GPU-Reconstruction kernel execution for industrial-scale reconstructions that dramatically improved voxel processing throughput. However, the improved kernel execution magnified other system bottlenecks such as host memory bandwidth and storage read/write bandwidth, thus hindering performance gains. This paper presents a multi-GPU-based reconstruction algorithm capable of efficiently reconstructing large volumes (between 64 gigavoxels and 1 teravoxel volumes) not only faster than traditional CPU- and GPU-based reconstruction algorithms but also while consuming significantly less energy. The reconstruction algorithm exploits the irregular kernel approach from previous work as well as a modularized MIMD-like environment, heterogeneous parallelism, as well as macro- and micro-scale dynamic task allocation. The result is a portable and flexible reconstruction algorithm capable of executing on a wide range of architectures including mobile computers, workstations, supercomputers, and modestly-sized hetero or homogeneous clusters with any number of graphics processors. © 2013 IEEE.

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Exploring diagnostic capabilities for application to new photovoltaic technologies

Quintana, Enrico C.; Quintana, Michael A.; Rolfe, Kevin D.; Thompson, Kyle R.

Explosive growth in photovoltaic markets has fueled new creative approaches that promise to cut costs and improve reliability of system components. However, market demands require rapid development of these new and innovative technologies in order to compete with more established products and capture market share. Often times diagnostics that assist in R&D do not exist or have not been applied due to the innovative nature of the proposed products. Some diagnostics such as IR imaging, electroluminescence, light IV, dark IV, x-rays, and ultrasound have been employed in the past and continue to serve in development of new products, however, innovative products with new materials, unique geometries, and previously unused manufacturing processes require additional or improved test capabilities. This fast-track product development cycle requires diagnostic capabilities to provide the information that confirms the integrity of manufacturing techniques and provides the feedback that can spawn confidence in process control, reliability and performance. This paper explores the use of digital radiography and computed tomography (CT) with other diagnostics to support photovoltaic R&D and manufacturing applications.

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Experiments for foam model development and validation

Mondy, L.A.; Gorby, Allen D.; Cote, Raymond O.; Castaneda, Jaime N.; Thompson, Kyle R.; Rao, Rekha R.; Moffat, Harry K.; Kraynik, Andrew M.; Russick, Edward M.; Adolf, Douglas B.; Grillet, Anne M.; Brotherton, Christopher M.; Bourdon, Christopher B.

A series of experiments has been performed to allow observation of the foaming process and the collection of temperature, rise rate, and microstructural data. Microfocus video is used in conjunction with particle image velocimetry (PIV) to elucidate the boundary condition at the wall. Rheology, reaction kinetics and density measurements complement the flow visualization. X-ray computed tomography (CT) is used to examine the cured foams to determine density gradients. These data provide input to a continuum level finite element model of the blowing process.

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Results 76–100 of 104
Results 76–100 of 104