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Campbell, Christopher

Publications and source records attributed to Campbell, Christopher.

13 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

2022 Site Environmental Report: Idaho National Laboratory

The INL Site’s operations, as well as the ongoing cleanup mission involve a commitment to environmental stewardship and full compliance with environmental protection laws. As part of this commitment, the INL Site Environmental Report is prepared annually to inform the public, regulators, stakeholders, and other interested parties of the INL Site’s environmental performance during the year. This report is published for U.S. Department of Energy, Idaho Operations Office (DOE-ID) in compliance with DOE O 231.1B, “Environment, Safety and Health Reporting.” The purpose of the report is to provide the following: (1) Present the INL Site, mission, and programs, (2) Report compliance status with applicable federal, state, and local regulations, (3) Describe the INL Site environmental programs and activities, (4) Summarize results of environmental monitoring, (5) Discuss potential radiation doses to the public residing in the vicinity of the INL Site, (6) Report on ecological monitoring and research conducted by contractors and affiliated agencies and by independent researchers through the Idaho National Environmental Research Park, (7) Describe quality assurance methods used to ensure confidence in monitoring data, and (8) Provide supplemental technical data and reports that support the INL Site Environmental Report (https://idahoeser.inl.gov/publications.html).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Ultrafast radiographic imaging and tracking: An overview of instruments, methods, data, and applications

Ultrafast radiographic imaging and tracking (U-RadIT) use state-of-the-art ionizing particle and light sources to experimentally study sub-nanosecond transients or dynamic processes in physics, chemistry, biology, geology, materials science and other fields. These processes are fundamental to modern technologies and applications, such as nuclear fusion energy, advanced manufacturing, communication, and green transportation, which often involve one mole or more atoms and elementary particles, and thus are challenging to compute by using the first principles of quantum physics or other forward models. One of the central problems in U-RadIT is to optimize information yield through, e.g. high-luminosity X-ray and particle sources, efficient imaging and tracking detectors, novel methods to collect data, and large-bandwidth online and offline data processing, regulated by the underlying physics, statistics, and computing power. We review and highlight recent progress in: (a.) Detectors such as high-speed complementary metal-oxide semiconductor (CMOS) cameras, hybrid pixelated array detectors integrated with Timepix4 and other application-specific integrated circuits (ASICs), and digital photon detectors; (b.) U-RadIT modalities such as dynamic phase contrast imaging, dynamic diffractive imaging, and four-dimensional (4D) particle tracking; (c.) U-RadIT data and algorithms such as neural networks and machine learning, and (d.) Applications in ultrafast dynamic material science using XFELs, synchrotrons and laser-driven sources. Hardware-centric approaches to U-RadIT optimization are constrained by detector material properties, low signal-to-noise ratio, high cost and long development cycles of critical hardware components such as ASICs. Interpretation of experimental data, including comparisons with forward models, is frequently hindered by sparse measurements, model and measurement uncertainties, and noise. Alternatively, U-RadIT make increasing use of data science and machine learning algorithms, including experimental implementations of compressed sensing. Machine learning and artificial intelligence approaches, refined by physics and materials information, may also contribute significantly to data interpretation, uncertainty quantification and U-RadIT optimization.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Accumulation of Succinyl Coenzyme A Perturbs the Methicillin-Resistant Staphylococcus aureus (MRSA) Succinylome and Is Associated with Increased Susceptibility to Beta-Lactam Antibiotics

mecA -dependent methicillin resistance in MRSA is subject to regulation by numerous accessory factors involved in cell wall biosynthesis, nucleotide signaling, and central metabolism. Here, we report that mutations in the TCA cycle gene, sucC , increased susceptibility to β-lactam antibiotics and was accompanied by significant accumulation of succinyl-CoA, which in turn perturbed lysine succinylation in the proteome.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

High-speed imaging of transition from fluid breakup to phase explosion in electric explosion of tungsten wires in air

High-speed visible imaging of sub-microsecond electric explosion of wires at the low specific energy deposition threshold reveals three distinct modes of wire failure as capacitor charge voltage and energy deposition are increased. For 100 micron diameter gold-plated tungsten wires of 2 cm length, deposited energies of 1.9 eV/atom produces a liquid column that undergoes hydrodynamic breakup into droplets with radii of order of wire diameter on timescales of 200 μs. Instability growth, column breakup, and droplet coalescence follow classic Rayleigh-Plateau predictions for instability of viscous fluid column. Above 3.2 eV/atom of deposited energy, wires are seen to abruptly transition to an expanding mixture of micron scale liquid-droplets and vapor within one frame (less than 3.33 μs), which has been termed ‘phase explosion’ in literature. Between these two limits, at 2.5 eV/atom of deposited energy, wire radius is unchanged for the first 10 μs before the onset of a rapid expansion and disintegration that resembles homogenous nucleation of mechanically unstable bubbles. Here, thermodynamic calculations are presented that separate cases by temperature obtained during heating: below boiling point, near boiling point, and exceeding boiling point.

42 ENGINEERING↗
DOE OSTI2019

Electronics Systems for the Gamma Ray Energy Tracking Nuclear Array (GRETA)

The Gamma Ray Energy Tracking Nuclear Array (GRETA), a 4-π germanium detector system capable of measuring energy and position (within better than 2mm rms) of gamma-ray interaction points and tracking multiple gamma-ray interactions, is being designed. GRETA is composed of 30 detector modules, each with four high purity germanium crystals. Four electronics modules will support the operation of the detectors: the Digitizer Module, the Signal Filter Board and the Trigger and Timing Modules. The Digitizer Module converts the analog information with analog to digital converters operating at 100 MS/s and sends the conversions through fiber optics to the Signal Filter Board. The Signal Filter Board digitally processes the data to determine the energy and timing information of the gamma interactions within a crystal. The Digitizer and Signal Filter Board send trigger information to the Trigger System. Different trigger algorithms for trigger decision are planned for the Trigger System. The Timing System provides the clock for the electronics systems and auxiliary detectors. In this paper we review the details of the planned GRETA Electronics System.

data acquisition↗