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At least 1,369 records · Page 76
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Experimental results of beryllium exposed to intense high energy proton beam pulses

Beryllium is extensively used in various accelerator beam lines and target facilities as a material for beam windows, and to a lesser extent, as secondary particle production targets. With increasing beam intensities of future accelerator facilities, it is critical to understand the response of beryllium under extreme conditions to reliably operate these components as well as avoid compromising particle production efficiency by limiting beam parameters. As a result, an exploratory experiment at CERN’s HiRadMat facility was carried out to take advantage of the test facility’s tunable high intensity proton beam to probe and investigate the damage mechanisms of several beryllium grades. The test matrix consisted of multiple arrays of thin discs of varying thicknesses as well as cylinders, each exposed to increasing beam intensities. This paper outlines the experimental measurements, as well as findings from Post-Irradiation-Examination (PIE) work where different imaging techniques were used to analyze and compare surface evolution and microstructural response of the test matrix specimens.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Random On-Board Pixel Sampling (ROPS) X-Ray Camera

Recent advances in compressed sensing theory and algorithms offer new possibilities for high-speed X-ray camera design. In many CMOS cameras, each pixel has an independent on-board circuit that includes an amplifier, noise rejection, signal shaper, an analog-to-digital converter (ADC), and optional in-pixel storage. When X-ray images are sparse, i.e., when one of the following cases is true: (a.) The number of pixels with true X-ray hits is much smaller than the total number of pixels; (b.) The X-ray information is redundant; or (c.) Some prior knowledge about the X-ray images exists, sparse sampling may be allowed. Here we first illustrate the feasibility of random on-board pixel sampling (ROPS) using an existing set of X-ray images, followed by a discussion about signal to noise as a function of pixel size. Next, we describe a possible circuit architecture to achieve random pixel access and in-pixel storage. The combination of a multilayer architecture, sparse on-chip sampling, and computational image techniques, is expected to facilitate the development and applications of high-speed X-ray camera technology.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

MUFFSgenMC: An Open Source Muon Flexible Framework for Spectral Generation for Monte Carlo Applications

A cosmic ray Muon Flexible Framework for Spectral Generation for Monte Carlo Applications (MUFFSgenMC) has been developed to support state-of-the-art cosmic ray muon detection and tomographic applications. The flexible framework allows for easy and fast creation of source terms for popular Monte Carlo applications such as GEANT4 and MCNP, which simplifies the process of simulations. The flexible framework contains a variety of analytical, numerical, and parametric models that capture the main characteristics of the muon energy and angular distributions in the range 0 to 90 and at arbitrary energies. The primary model for muon energy distribution is an implementation of the Smith and Duller phenomenological model. The predictions for muon energies in the range from 1 GeV to 1 TeV and zenith angles 0 to 90 are validated against an extensive series of experimental spectrum measurements. Finally, the open source code available on Matlab’s Mathworks File Exchange (https://www.mathworks.com/matlabcentral/fileexchange/65585-muffsgenmc) was written to allow users to easily modify and expand the code. MUFFSgenMC can facilitate the study of cosmic ray muons for nuclear nonproliferation applications and will enable the development of new muon-based detection and imaging techniques by providing an easy source term generator.

Greulich, Christopher↗
DOE OSTI2016

Compounds for use in diagnosing and treating melanoma, including metastatic melanoma and methods related to same

The present invention is directed to novel non-invasive diagnostic tools/compounds comprising a cyclic peptide wherein the compound binds to a MSH receptor to image and treat cancers, especially, melanoma, including metastatic melanoma in vivo. The present invention represents a clear advance in the art which presently relies on tissue biopsy for diagnoses of these cancers. The novel imaging probes are capable of detecting cancerous melanoma cells, as well as their metastatic spread in tissues. This represents a quantum step forward in the diagnosis and treatment of melanoma, including metastatic melanoma using non-invasive molecular imaging techniques. The novel probes of the present invention will also be useful to initiate therapy for melanoma as well as monitor patients response to chemotherapy treatments and other interventions or therapies used in the treatment of melanoma/metastatic melanoma. Compounds according to the present invention may be used as diagnostic tools for a number of conditions and diseases states as well as therapeutic agents for treating such conditions and disease states.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Compounds for use in diagnosing and treating melanoma, including metastatic melanoma and methods related to same

The present invention is directed to novel non-invasive diagnostic tools/compounds comprising a cyclic peptide wherein the compound binds to a MSH receptor to image and treat cancers, especially, melanoma, including metastatic melanoma in vivo. The present invention represents a clear advance in the art which presently relies on tissue biopsy for diagnoses of these cancers. The novel imaging probes are capable of detecting cancerous melanoma cells, as well as their metastatic spread in tissues. This represents a quantum step forward in the diagnosis and treatment of melanoma, including metastatic melanoma using non-invasive molecular imaging techniques. The novel probes of the present invention will also be useful to initiate therapy for melanoma as well as monitor patients response to chemotherapy treatments and other interventions or therapies used in the treatment of melanoma/metastatic melanoma. Compounds according to the present invention may be used as diagnostic tools for a number of conditions and diseases states as well as therapeutic agents for treating such conditions and disease states.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Super Hot EGS and the Newberry Deep Drilling Project

A productive geothermal well drilled into super-hot rock (SHR) with a temperature above 400°C will produce super-critical fluid. At a flow rate of 60 kg/s, a SHR well could produce 50 MWe compared to 5-7 MWe for the same flow at 200°C. Even though these deeper, super-hot wells will cost more, the high energy density means power produced by engineered geothermal systems (EGS) can meet the market ($46 MW-hr) by directly tapping the heat source. We propose a proof of concept where hot rock is close to the surface (~5 km), and the cost of drilling and EGS stimulation will be lowest. A suitable, ready-to-go SHR site is on Newberry Volcano, Oregon, one of the largest geothermal heat reservoirs in the USA, extensively studied for the last 40 years. Millions of dollars have already been invested in the site by private geothermal developers and the US Department of Energy (DOE), resulting in a ready-to-use facility with the necessary infrastructure, environmental permits, land commitments, and monitoring plans. The Newberry Deep Drilling Project (NDDP) will be located at an idle geothermal exploration well, NWG 46-16, drilled in 2008, 3500 m deep and 320°C at bottom, which will be deepened another 1000 to 1300 m to reach 500 °C. The original well was drilled with few lost circulation zones and the temperature profile indicates conductive heat flow. Compared to other SHR projects world-wide, this well would return more materials (cuttings, core and fluids) with more predictable drilling conditions, thus providing a suite of data near and across the brittle-ductile transition in silicarich rocks. After drilling, a hydraulic well stimulation will both change the pore pressure in fractures and cool the fracture walls resulting in permeability enhancement through both thermal fracturing, and hydro-shearing. The first step for the NDDP was an International Continental Drilling Program (ICDP) sponsored workshop held at the OSU-Cascades campus in Bend from Sept. 10-14, 2017. The workshop concluded by setting ambitious goals for NDDP: 1) test EGS above the critical point of water, 2) collect samples of rocks within the brittle-ductile transition, 3) investigate volcanic hazards, 4) study magmatic geomechanics, 5) calibrate geophysical imaging techniques, and 6) test technology for drilling, well completion, and geophysical monitoring in a very high temperature environment. The second step, completed January 15, 2018, was submitting a proposal to ICDP for 46-16 deepening. The next steps will be to continue building a team with project, technology, and investment partners to make NDDP a reality.

EGS, Geothermal, Newberry↗
DOE OSTI2021

PET imaging of zinc transport

A method for producing a solution including a positron emitting zinc cation of 63Zn, and the method comprises bombarding a solution target including 63 Cu with high energy protons to produce a solution including a positron emitting zinc cation. A method for detecting or ruling out Alzheimer's disease in a patient comprises administering to a patient a detectable amount of a compound including a positron emitting zinc cation, wherein the zinc cation is targeted to β-amyloid in the patient, and acquiring an image to detect the presence or absence of β-amyloid in the patient. A method for detecting or ruling out cancer in a patient comprises administering to a patient a detectable amount of a compound including a positron emitting zinc cation, wherein the zinc cation is targeted to tissue in the patient; and acquiring an image using a medical imaging technique to detect zinc distribution in tissue in the patient.

DeGrado, Timothy R.↗
DOE OSTI2021

Compositions for use in diagnosing and treating melanoma, including metastatic melanoma and methods related to same

The present invention is directed to novel non-invasive diagnostic tools/compounds comprising a cyclic peptide wherein the compound binds to a MSH receptor to image and treat cancers, especially, melanoma, including metastatic melanoma in vivo. The present invention represents a clear advance in the art which presently relies on tissue biopsy for diagnoses of these cancers. The novel imaging probes are capable of detecting cancerous melanoma cells, as well as their metastatic spread in tissues. This represents a quantum step forward in the diagnosis and treatment of melanoma, including metastatic melanoma using non-invasive molecular imaging techniques. The novel probes of the present invention will also be useful to initiate therapy for melanoma as well as monitor patients response to chemotherapy treatments and other interventions or therapies used in the treatment of melanoma/metastatic melanoma. Compounds according to the present invention may be used as diagnostic tools for a number of conditions and diseases states as well as therapeutic agents for treating such conditions and disease states.

Miao, Yubin↗
DOE OSTI2022

Indigenous Organic Molecular Biosignatures are Detectable via ToF-SIMS of a Kerogen-rich Jurassic Clay

Time of Flight - Secondary Ion Mass Spectrometry (ToF-SIMS) is a Mass Spectrometry (MS) imaging technique that can be used in conjunction with traditional organic geochemical analysis (organics extracted from a crushed sample) in order to determine how molecules observed in the organic extracts were incorporated into a particular rock sample. This type of analysis may be used on samples collected as part of Mars Sample Return (MSR) in order to determine if potential organic compounds were indigenous to Mars or whether they are contaminants.Here we show that Organic Molecular Biosignatures (OMBs including steranes and derivatives of a carotenoid) are detectable via ToF-SIMS within a Jurassic mudstone. The OMBs are only detectable in areas with high organic carbon, likely kerogen, indicating that they are indigenous to the rock. We conclude that: I) Indigenous OMBs are detectable via ToF-SIMS in ancient, kerogen-rich samples; II) the presence of a molecular ion strengthens the interpretation of ToF-SIMS spectra of complex natural material, and III) the spatial co-occurrence of kerogen and potentially indigenous OMBs in ancient sediments is a valid test of their character. These conclusions are directly relevant to MSR sample selection as well as the analysis of MSR samples upon return.

Pasterski, Michael↗
DOE OSTI2022

Gamma-Ray Imaging to Monitor Accumulating Holdup

Over time, nuclear materials can accumulate in process equipment and keeping track of such material is of interest to many stakeholder communities including safeguards, process monitoring, criticality safety, and radiological safety. Passive gamma-ray imaging provides a visual and quantitative tool that can be applied to this problem, allowing one to determine the amount of material present from the images. In this work we emulate the accumulation of highly enriched uranium (HEU) in a large rectangular stainless-steel duct by stacking 5, 27 × 50 cm2 cards, each of which has approximately 11 g of 235U in oxide form distributed across its surface, behind each other. A series of images were collected using a coded-aperture gamma-ray imager, starting with a single card, adding a second card, etc. Long integrations were collected to allow evaluating the performance of the approach as a function of integration time. The images are analyzed using first principles to determine the amount of material in each image. The results are compared to the known amount of material in each configuration, and as a function of time. The analysis includes a first-principles error propagation and to further evaluate the uncertainty, a boot-strap sampling approach is also applied to the data. The work offers a proof of concept for unattended monitoring of uranium holdup with a quantitative gamma-ray imaging technique.

Ziock, Klaus-Peter↗
DOE OSTI2022

What does it take to “see” air leakage through a building envelope?

Unwanted air leakage in buildings can cause health and comfort issues for the building occupants and contribute to rot and mold growth in building materials. Leakage also contributes to unnecessary energy consumption ~4 quads (1172 TWh) per year in the buildings sector in the United States. Finding and repairing leaks through the building envelope can improve the energy efficiency, comfort, air-quality, and moisture durability of the building stock. Typical methods of locating air leakage, such as infrared imaging or smoke tracing, rely on concurrent blower door operation which also measures the total leakage rate of the building. These methods can be disruptive to occupants and can’t measure the contribution of individual leaks to prioritize sealing efforts. ORNL is working on a refraction-based fluid flow imaging technique that can measure the leakage rate of individual leaks from the outside of the building. The working principle of this device is based on the refraction of light caused by the exfiltration because there is a small difference in density between the exfiltration and ambient air. We will discuss the operation of the air leak detector and key variables that affect its performance. We will also present preliminary results showing the visualization capability of this new air leak detector under different conditions. Experiments were completed with different claddings, air temperatures, and lighting conditions.

Boudreaux, Philip↗
DOE OSTI2014

Development of a series of Korean pediatric and adult head computational phantoms and application to nuclear medicine dosimetry - Paper 26

Over the past decades, advances in Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) imaging techniques and an increasing number of new radiopharmaceuticals have resulted in a surge of neuroimaging applications in nuclear medicine on pediatric and adult patients. It is not feasible to directly measure the absorbed dose to the organs of the human body from nuclear medicine procedures. The formalism of the Medical Internal Radiation Dose (MIRD) committee of the Society of Nuclear Medicine has been adopted as the calculation method to estimate radiation dose to target organs from radionuclides distributed in source organs. The absorbed dose to a target organ from different types of radionuclides distributed within source organs can be estimated by the products of the time-integrated activity in each source region and organ dose conversion coefficients, called S values (Gy/MBq-s). S values are computed from a comprehensive set of Specific Absorbed Fraction (SAF), which are calculated from computational human phantoms with realistic anatomical structures coupled with Monte Carlo transport technique. The current SAF data for pediatric and adult head and brain dosimetry is based on a series of stylized computational phantoms. However, dosimetric errors caused by the unrealistic anatomy of stylized phantoms in internal dosimetry calculations have been reported by several studies. In the current study, we developed a series of realistic computational head phantoms representing 6, 9, 12, 15, and 22-year-old standard Korean males, and computed a comprehensive set of SAFs using the phantoms coupled with Monte Carlo transport technique. (authors)

61 RADIATION PROTECTION AND DOSIMETRY↗
NASA NTRS1991

Calibrated imaging radar polarimetry - Technique, examples, and applications

The authors developed a calibration procedure for imaging radar polarimeters and applied it to a set of images acquired by the NASA DC-8 multifrequency radar system. The technique requires the use of ground reflectors known cross-section for absolute calibration, that is, solution for sigma exp 0; however, the image data themselves can usually provide all information necessary for phase calibration and for antenna crosstalk correction. The accuracy of the approach, as measured by calculating the cross-section residuals of known targets in each calibrated scene, is on the order of +/- 1-2 dB at P- and C-band, but improves to +/- 0.5 dB at L-band. The authors present the results of applying this technique to radar scenes of lava flows of varying roughness, temperate and tropical rain forests, and ocean water surfaces. They also present several example applications which are feasible with calibrated data but which would be difficult to implement with uncalibrated data.

Zebker, Howard A.↗
DOE OSTI2016

Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 11: Quantification of chest wall motion during deep inspiration breast hold treatments using cine EPID images and a physics based algorithm

Purpose: This work presents an algorithm used to quantify intra-fraction motion for patients treated using deep inspiration breath hold (DIBH). The algorithm quantifies the position of the chest wall in breast tangent fields using electronic portal images. Methods: The algorithm assumes that image profiles, taken along a direction perpendicular to the medial border of the field, follow a monotonically and smooth decreasing function. This assumption is invalid in the presence of lung and can be used to calculate chest wall position. The algorithm was validated by determining the position of the chest wall for varying field edge positions in portal images of a thoracic phantom. The algorithm was used to quantify intra-fraction motion in cine images for 7 patients treated with DIBH. Results: Phantom results show that changes in the distance between chest wall and field edge were accurate within 0.1 mm on average. For a fixed field edge, the algorithm calculates the position of the chest wall with a 0.2 mm standard deviation. Intra-fraction motion for DIBH patients was within 1 mm 91.4% of the time and within 1.5 mm 97.9% of the time. The maximum intra-fraction motion was 3.0 mm. Conclusions: A physics based algorithm was developed and can be used to quantify the position of chest wall irradiated in tangent portal images with an accuracy of 0.1 mm and precision of 0.6 mm. Intra-fraction motion for patients treated with DIBH at our clinic is less than 3 mm.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

AUTOMATICALLY DETECTING AND TRACKING CORONAL MASS EJECTIONS. I. SEPARATION OF DYNAMIC AND QUIESCENT COMPONENTS IN CORONAGRAPH IMAGES

Automated techniques for detecting and tracking coronal mass ejections (CMEs) in coronagraph data are of ever increasing importance for space weather monitoring and forecasting. They serve to remove the biases and tedium of human interpretation, and provide the robust analysis necessary for statistical studies across large numbers of observations. An important requirement in their operation is that they satisfactorily distinguish the CME structure from the background quiescent coronal structure (streamers, coronal holes). Many studies resort to some form of time differencing to achieve this, despite the errors inherent in such an approach-notably spatiotemporal crosstalk. This article describes a new deconvolution technique that separates coronagraph images into quiescent and dynamic components. A set of synthetic observations made from a sophisticated model corona and CME demonstrates the validity and effectiveness of the technique in isolating the CME signal. Applied to observations by the LASCO C2 and C3 coronagraphs, the structure of a faint CME is revealed in detail despite the presence of background streamers that are several times brighter than the CME. The technique is also demonstrated to work on SECCHI/COR2 data, and new possibilities for estimating the three-dimensional structure of CMEs using the multiple viewing angles are discussed. Although quiescent coronal structures and CMEs are intrinsically linked, and although their interaction is an unavoidable source of error in any separation process, we show in a companion paper that the deconvolution approach outlined here is a robust and accurate method for rigorous CME analysis. Such an approach is a prerequisite to the higher-level detection and classification of CME structure and kinematics.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Characterizing Biomass Feedstock Transport Properties Using State of the Art Imaging and Computational Techniques

The microstructure of lignocellulosic biomass determines heat and mass transfer during conversion processes. We present a novel method for characterizing the transport properties of biomass using advanced imaging and computational techniques. The microstructure of two woody feedstocks, red oak and Douglas fir, before and after pyrolysis, is revealed using X-ray computed tomography (XCT). Transport properties are calculated from the XCT images, and principal permeability tensors are calculated using an immersed boundary-based finite volume solver to model gas flow through the geometries. We observe that the permeabilities of native biomass are distinctly anisotropic, however, this anisotropy is greatly reduced after pyrolysis.

adaptive mesh refinement↗