Search NASA⌕ Search

SEARCH · Search NASA

Results for “Field Operators”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The bottom-up EFT: complete UV resonances of the SMEFT operators

The standard model effective field theory (SMEFT) provides systematic parameterization of all possible new physics above the electroweak scale. According to the amplitude-operator correspondence, an effective operator can be decomposed into a linear combination of several j-basis operators, which correspond to local amplitudes carrying certain spin and gauge quantum numbers in a particular scattering channel. Based on the Poincare and gauge symmetries of scattering amplitude, we construct the j-basis using the Casimir method for both the Lorentz and gauge sectors. The quantum numbers of the j-basis operators fix the quantum numbers of any intermediate state in the corresponding amplitudes, such as a UV resonance. This can be re-interpreted as the j-basis/UV correspondence, thus obtaining the j-bases in all partitions of fields for an operator amounts to finding all of its UV origins at tree level, constituting the central part of the bottom-up EFT framework. Applying the j-basis analysis to SMEFT, we obtain a complete list of possible tree-level UV origins of the effective operators at the dimension 5, 6, 7, and all the bosonic operators at dimension 8.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Energy Harvesting Remotely Monitored Sealing Array (RMSA) (Field Test Annual Report)

Sandia National Laboratories (SNL) is investigating photovoltaic (PV) cell configurations, integrating them with the battery-operated Remotely Monitored Sealing Array (RMSA), and testing and evaluating performance for enhanced battery life under various lighting conditions at a facility at the Savannah River Site (SRS) or Savannah River National Laboratory (SRNL). Unattended safeguards equipment (e.g. seals) incorporates many low-power electronic circuits, which are often powered by expensive and environmentally toxic lithium batteries. These batteries must periodically be replaced, adding a radiological hazard for both safeguards inspectors and operators. An extended field test of these prototype PV energy harvesting (EH) RMSAs at an operational nuclear facility will give additional data and allow for an analysis of this technology in a variety of realistic conditions, which will be documented in a final report. RMSAs are used for this testing, but SNL envisions energy harvesting technology may be applicable to additional safeguards equipment.

14 SOLAR ENERGY↗
NASA NTRS1991

Los Alamos NEP research in advanced plasma thrusters

Research was initiated in advanced plasma thrusters that capitalizes on lab capabilities in plasma science and technology. The goal of the program was to examine the scaling issues of magnetoplasmadynamic (MPD) thruster performance in support of NASA's MPD thruster development program. The objective was to address multi-megawatt, large scale, quasi-steady state MPD thruster performance. Results to date include a new quasi-steady state operating regime which was obtained at space exploration initiative relevant power levels, that enables direct coaxial gun-MPD comparisons of thruster physics and performance. The radiative losses are neglible. Operation with an applied axial magnetic field shows the same operational stability and exhaust plume uniformity benefits seen in MPD thrusters. Observed gun impedance is in close agreement with the magnetic Bernoulli model predictions. Spatial and temporal measurements of magnetic field, electric field, plasma density, electron temperature, and ion/neutral energy distribution are underway. Model applications to advanced mission logistics are also underway.

Schoenberg, Kurt↗
NASA NTRS1985

Electric Field Containerless Processing Technology

The objective of this task is to develop the science and technology base required to design and construct a high temperature electric field positioning module that could be used by materials scientists to conduct containerless science experiments in a low gravity environment. Containerless science modules that employ electric fields to position and manipulate samples offer several advantages over acoustic or electromagnetic systems. The electric field system will operate not only at atmospheric pressures but also in a vacuum, in contrast to the acoustic modules which can only operate in atmosphere where the acoustic forces are sufficient. The electric field technique puts minimum energy into the sample, whereas the electromagnetic system can deposit energy into the sample through eddy current heat as well as physical mixing in the sample. Two types of electric field modules have been constructed and tested to date. One employs a charged sample and uses electrostatic forces to position and control the sample. The second type of module induces electrical polarization of the sample and electric field gradients to position and control the sample.

Elleman, D. D.↗
DOE OSTI2016

Impact of High Performance Computing on the Detailed Simulation of Subsurface Flow and Contaminant Transport Using eSTOMP - 16341

The ability to model subsurface processes at the field-scale is essential to site closure and remedial action decisions. Field-scale models often require high-performance computing to meet the computational demands associated with complex systems, model calibration, and uncertainty quantification. eSTOMP, a parallel version of STOMP, is an analytical tool that meets the need for investigating coupled processes in the subsurface involving regional multi-fluid flow and biogeochemistry. The scalability of eSTOMP makes it ideal for simulating contaminant and geochemical reactive transport when long run times result from execution of a serial code. To demonstrate the impact of high-performance computation on subsurface analyses, the application of eSTOMP is presented for two sites. The first site involves uranium surface complexation within a highly dynamic, variably saturated flow field. The use of this model in conjunction with continued field monitoring is expected to provide a rigorous basis for developing operational strategies for field remediation and for defining defensible remediation endpoints. The second site involves the long-term dissolution of low-level radioactive glass emplaced within a near-surface repository. The waste form release rate is evaluated by modeling the basic physical and chemical processes that are known to control the waste form dissolution behavior, including pH and composition of the fluid contacting the glass. Simulations demonstrate that glass dissolution rates vary both in time and as a function of position within the disposal system, and that a 'leach rate' or radionuclide release rate parameter can only be estimated after identifying these impacts in a dynamic system. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Field Validation of Innovative Air-Source Heat Pumps for Cold-Climate Heating Applications

Air-source heat pumps (ASHPs) have historically found application in milder climates in the United States (US). Their application in cold climates has been hindered by reduced performance as outdoor temperatures fall below freezing and the need for backup or auxiliary electric resistance heaters to meet peak heating loads. Recent advances in cold-climate air-source heat pumps (ccASHPs) with features such as variable-speed compressors, multistage systems, and highly optimized thermal design have improved performance by increasing the coefficient of performance (COP), low-ambient-temperature capacity, and heating seasonal performance factor (HSPF) dramatically. Despite their benefits, ccASHPs are still not widely prescribed for cold climate conditions. This is due in part to a lack of verified, demonstrated performance and analysis in cold climates. Ultimately, high-efficiency ccASHPs play a key role in emerging energy/grid renovation efforts in addition to their potential energy savings and avoided carbon emissions, but their actual performance in various cold climate field settings must be better understood. The primary objective of this project was to measure the in-field performance of variable-capacity air-source heat pumps in cold climates with the goal of enabling the development of field-based performance maps. Specifically, the study looked at how the heat pumps operated in the field, the frequency of cycling, the frequency of defrost events, and the time spent in each mode of operation. The results are intended to be used by DOE to inform research and development of energy-efficient equipment and to develop guidelines for optimizing primary energy savings when using air-source heat pumps in heating-dominated regions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Site Environmental Report for Calendar Year 2013: DOE Operations at The Boeing Company, Santa Susana Field Laboratory, Area IV

This Annual Site Environmental Report (ASER) for 2013 describes the environmental conditions related to work performed for the Department of Energy (DOE) at Area IV of the Santa Susana Field Laboratory (SSFL). The Energy Technology Engineering Center (ETEC), a government-owned, company-operated test facility, was located in Area IV. The operations in Area IV included development, fabrication, operation and disassembly of nuclear reactors, reactor fuel, and other radioactive materials. Other activities in the area involved the operation of large-scale liquid metal facilities that were used for testing non-nuclear liquid metal fast breeder reactor components. All nuclear work was terminated in 1988, and all subsequent radiological work has been directed toward environmental restoration and decontamination and decommissioning (D&D) of the former nuclear facilities and their associated sites. Liquid metal research and development ended in 2002. Since May 2007, the D&D operations in Area IV have been suspended by the DOE, but the environmental monitoring and characterization programs have continued. Results of the radiological monitoring program for the calendar year 2013 continue to indicate that there are no significant releases of radioactive material from Area IV of SSFL. All potential exposure pathways are sampled and/or monitored, including air, soil, surface water, groundwater, direct radiation, transfer of property (land, structures, waste), and recycling. Due to the suspension of D&D activities in Area IV, no effluents were released into the atmosphere during 2013. Therefore, the potential radiation dose to the general public through airborne release was zero. Similarly, the radiation dose to an offsite member of the public (maximally exposed individual) due to direct radiation from SSFL is indistinguishable from background. All radioactive wastes are processed for disposal at DOE disposal sites and/or other licensed sites approved by DOE for radioactive waste disposal. No liquid radioactive wastes were released into the environment in 2013.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Site Environmental Report For Calendar Year 2012. DOE Operations at The Boeing Company Santa Susana Field Laboratory, Area IV

This Annual Site Environmental Report (ASER) for 2012 describes the environmental conditions related to work performed for the Department of Energy (DOE) at Area IV of Boeing’s Santa Susana Field Laboratory (SSFL). The Energy Technology Engineering Center (ETEC), a government-owned, company-operated test facility, was located in Area IV. The operations in Area IV included development, fabrication, operation and disassembly of nuclear reactors, reactor fuel, and other radioactive materials. Other activities in the area involved the operation of large-scale liquid metal facilities that were used for testing non-nuclear liquid metal fast breeder reactor components. All nuclear work was terminated in 1988, and all subsequent radiological work has been directed toward environmental restoration and decontamination and decommissioning (D&D) of the former nuclear facilities and their associated sites. Liquid metal research and development ended in 2002. Since May 2007, the D&D operations in Area IV have been suspended by the DOE, but the environmental monitoring and characterization programs have continued. Results of the radiological monitoring program for the calendar year 2012 continue to indicate that there are no significant releases of radioactive material from Area IV of SSFL. All potential exposure pathways are sampled and/or monitored, including air, soil, surface water, groundwater, direct radiation, transfer of property (land, structures, waste), and recycling.

Liu, Ning↗
DOE OSTI2017

Studies of Zγ production in association with a high-mass dijet system in pp collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

The production of a Z boson and a photon in association with a high-mass dijet system is studied using 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV recorded with the ATLAS detector in 2012 at the Large Hadron Collider. Final states with a photon and a Z boson decaying into a pair of either electrons, muons, or neutrinos are analysed. Electroweak and total pp → Zγjj cross-sections are extracted in two fiducial regions with different sensitivities to electroweak production processes. Quartic couplings of vector bosons are studied in regions of phase space with an enhanced contribution from pure electroweak production, sensitive to vector-boson scattering processes VV → Zγ. Finally, no deviations from Standard Model predictions are observed and constraints are placed on anomalous couplings parameterized by higher-dimensional operators using effective field theory.

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

Alcator C-Mod (Final Technical Report)

Alcator C-Mod is the third in a series of compact high-field tokamaks built and operated on the MIT campus, the first to incorporate advanced shaping and poloidal divertors. For most of its 23 year operational history, C-Mod was the only diverted tokamak in the world program exclusively using all metal high-Z plasma facing components, and the only diverted tokamak able to operate at and above the magnetic field strength of ITER, and for many other burning plasma tokamak designs. The C-Mod facility also exclusively used RF waves for non-inductive heating and current drive, highly relevant to burning plasma applications and likely to be the main such tools in any commercial tokamak power reactor. A comprehensive summary of the key technical accomplishments from the C-Mod program is published in the review paper, M. Greenwald, et al., Phys. Plasmas 21(2014)110501. This final report contains a brief overview of those results, along with updates covering the final 3 years of operation, through September 2016. Ongoing analysis and modeling based on the archive of Alcator C-Mod data continues to provide new results, and this can be expected to continue for many years to come.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Evaluation of Component Reliability in Photovoltaic Systems using Field Failure Statistics

Ongoing operations and maintenance (O&M) are needed to ensure photovoltaic (PV) systems continue to operate and meet production targets over the lifecycle of the system. Although average costs to operate and maintain PV systems have been decreasing over time, reported costs can vary significantly at the plant level. Estimating O&M costs accurately is important for informing financial planning and tracking activities, and subsequently lowering the levelized cost of electricity (LCOE) of PV systems. This report describes a methodology for improving O&M planning estimates by using empirically-derived failure statistics to capture component reliability in the field. The report also summarizes failure patterns observed for specific PV components and local environmental conditions observed in Sandia's PV Reliability, Operations & Maintenance (PVROM) database, a collection of field records across 800+ systems in the U.S. Where system-specific or fleet-specific data are lacking, PVROM-derived failure distribution values can be used to inform cost modeling and other reliability analyses to evaluate opportunities for performance improvements.

14 SOLAR ENERGY↗
DOE OSTI2017

Localized excitations from localized unitary operators

Localized unitary operators are basic probes of locality and causality in quantum systems: localized unitary operators create localized excitations in entangled states. Working with an explicit form, we explore properties of these operators in quantum mechanics and quantum field theory. We show that, unlike unitary operators, local non-unitary operators generically create non-local excitations. We present a local picture for quantum systems in which localized experimentalists can only act through localized Hamiltonian deformations, and therefore localized unitary operators. We demonstrate that localized unitary operators model certain quantum quenches exactly. We show how the Reeh–Schlieder theorem follows intuitively from basic properties of entanglement, non-unitary operators, and the local picture. We show that a recent quasi-particle picture for excited-state entanglement entropy in conformal field theories is not universal for all local operators. We prove a causality relation for entanglement entropy and connect our results to the AdS/CFT correspondence. - Highlights: • Local unitary operators create local excitations. • Local non-unitary operators generically create non-local excitations. • Reeh–Schlieder follows intuitively from non-locality of local operator excitations. • Local operators of definite conformal dimension create local excitations. • Quasi-particle picture for entanglement entropy fails for some local operators.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Magnetic‐Field‐Switchable Laser via Optical Pumping of Rubrene

Abstract Volumetric optical imaging of magnetic fields is challenging with existing magneto‐optical materials, motivating the search for dyes with strong magnetic field interactions, distinct emission spectra, and an ability to withstand high photon flux and incorporation within samples. Here, the magnetic field effect on singlet‐exciton fission is exploited to demonstrate spatial imaging of magnetic fields in a thin film of rubrene. Doping rubrene with the high‐quantum yield dye dibenzotetraphenylperiflanthene (DBP) is shown to enable optically pumped, slab waveguide lasing. This laser is magnetic‐field‐switchable: when operated just below the lasing threshold, application of a 0.4 T magnetic field switches the device between nonlasing and lasing modes, accompanied by an intensity modulation of +360%. This is thought to be the first demonstration of a magnetically switchable laser, as well as the largest magnetically induced change in emission brightness in a singlet‐fission material to date. These results demonstrate that singlet‐fission materials are promising materials for magnetic sensing applications and could inspire a new class of magneto‐optical modulators.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Performance demonstration of vacuum microwave components critical for the operation of the ITER low-field side reflectometer

Final design studies in preparation for manufacturing have been performed for functional components of the vacuum portion of the ITER Low-Field Side Reflectometer (LFSR). These components consist of an antenna array, electron cyclotron heating (ECH) protection mirrors, phase calibration mirrors, and vacuum windows. Evaluation of these components was conducted at the LFSR test facility and DIII-D. The antenna array consists of six corrugated-waveguide antennas for simultaneous profile, fluctuation, and Doppler measurements. A diffraction grating, incorporated into the plasma-facing miter bend, provides protection of sensitive components from stray ECH at 170 GHz. For in situ phase calibration of the LFSR profile reflectometer, an embossed mirror is incorporated into the adjacent miter bend. Measurements of the radiated beam profile indicate that these components have a small, acceptable effect on mode conversion and beam quality. Baseline transmission characteristics of the dual-disk vacuum window are obtained and are used to guide ongoing developments. Preliminary simulations indicate that a surface-relief structure on the window surfaces can greatly improve transmission. The workability of real-time phase measurements was demonstrated on the DIII-D profile reflectometer. The new automated real-time analysis agrees well with the standard post-processing routine.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Ta, Ti and Hf effects on Nb 3 Sn high-field performance: temperature-dependent dopant occupancy and failure of Kramer extrapolation

The increasing demand for improving the high-field (16-22 T) performance of Nb 3 Sn conductors requires a better understanding of the properties of modern wires much closer to irreversibility field, H Irr . In this study we investigated the impact of Ta, Ti and Hf doping on the high-field pinning properties, the upper critical field, H c2 , and H Irr . We found that the pinning force curves of commercial Ti and Ta doped wires at different temperatures do not scale and that the Kramer extrapolation, typically used by magnet designers to estimate high-field critical current density and magnet operational margins from lower field data, is not reliable and significantly overestimates the actual H Irr . In contrast, new laboratory scale conductors made with Nb-Ta-Hf alloy have improved high-field J c performance and, despite contributions by both grain boundary and point defect pinning mechanisms, have more predictable high-field behavior. Using Extended X-ray Absorption Fine Structure spectroscopy, EXAFS, we found that for the commercial Ta and Ti doped conductors, the Ta site occupancy in the A15 structure gradually changes with the heat treatment temperature whereas Ti is always located on the Nb site with clear consequences for H c2 . Finally, this work reveals the still limited understanding of what determines H c2 , H Irr and the high-field J c performance of Nb 3 Sn and the complexity of optimizing these conductors so that they can reach their full potential for high-field applications.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Systematically localizable operators for quantum simulations of quantum field theories

Correlations and measures of entanglement in ground-state wave functions of relativistic quantum field theories are spatially localized over length scales set by the mass of the field. We utilize this localization to design digital quantum circuits for preparing the ground states of lattice scalar quantum field theories. Controlled rotations that are exponentially localized in their position-space extent are found to provide exponentially convergent wave function fidelity. These angles scale with the correlation between sites and the classical two-point correlation function, as opposed to the more localized mutual information or the hyperlocalized (1×1)-site negativity. We anticipate that further investigations will uncover quantum circuit designs with controlled rotations dictated by the measures of entanglement. This work is expected to impact quantum simulations of systems of importance to nuclear physics, high-energy physics, and basic energy sciences research.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Reservoir Dynamics in Proposed Operational Scenarios Where CO 2 -EOR Fields are Transitioned From CO 2 -Flood Enhanced Oil Recovery to Dedicated Carbon Storage: A Field Case Study

This study models the transition of CO 2 -enhanced oil recovery (CO 2 -EOR) fields to dedicated carbon storage using a generalized reservoir model informed by real field data, SACROC. Through scenario-based simulations, the work evaluates how reservoir depletion levels, boundary conditions, fluid properties, and domain size affect pressure buildup, CO 2 plume migration, and long-term containment performance. The results inform practices for repurposing oil fields into reliable CO 2 storage sites.

02 PETROLEUM↗