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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.

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At least 1,171 records · Page 65

Stealth dark matter spectrum using Laplacian Heaviside smearing and irreducible representations

We present nonperturbative lattice calculations in the quenched approximation of the low-lying meson and baryon spectrum of the SU(4) gauge theory with fundamental fermion constituents. This theory is one instance of stealth dark matter, a class of strongly coupled theories, where the lowest mass stable baryon is the dark matter candidate. This work constitutes the first milestone in the program to study stealth dark matter self-interactions. Here, we focus on reducing excited state contamination in the single-baryon channel by applying the Laplacian Heaviside method, as well as projecting our baryon operators onto the irreducible representations of the octahedral group. We compare our resulting spectrum to previous work involving Gaussian smeared nonprojected operators and find good agreement with reduced statistical uncertainties. We also present the spectrum of the low-lying odd-parity baryons for the first time.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

SU-E-J-162: Quality Assurance Procedures for MR Guided Focused Ultrasound Treatment of Bone Metastasis

Purpose: The purpose of this work is to develop and verify our quality assurance (QA) procedures to ensure the safety and efficacy of MR-guided focused ultrasound (MRgFUS) treatment of bone metastases. Methods: A practical QA program was developed. Monthly and daily QA (DQA) procedures were performed. The major QA items included the checks of the machine hardware, software and patient safety features. Briefly, these checks/tests include: 1) the cooling system reservoir and treatment table; 2) power to the treatment table; 3) the MR coil; 4) the transducer position with MRI; 5) image display on the treatment work station; 6) the effective focal spot in 3 directions using MR thermometry; and 7) all the safety devices including a sonication lamp, and the emergency stop-sonication switches. In order to avoid patient skin burn, it is important to remove gas bubbles in the interfaces between the treatment table and the gel pad, and the gel pad and patients skin during the patient setup. Our QA procedures have been verified and evaluated through patient treatments. Seven patients with scapula, humeral head, sacrum, ilium, pubic ramus and acetabular bone metastases were treated using MRgFUS. Results: Our study showed that all seven patients tolerated the MRgFUS treatment well. No skin toxicity or other complications were observed. The pain score (0–10) using the visual analog scale (VAS) was significantly reduced from 8.0 ± 1.1 before treatment to 4.7 ± 3.0, 3.0 ± 1.5, 3.2 ± 2.8 and 3.4 ± 1.5 at one day, one month, two months and three months after the MRgFUS treatment, respectively. Conclusion: We demonstrated that with the appropriate QA procedures, MRgFUS is a safe, effective and noninvasive treatment modality for palliation of bone metastases.

60 APPLIED LIFE SCIENCES↗

Topology optimization of 3D photonic crystals with complete bandgaps

The design of photonic crystals with complete bandgaps has recently received considerable research focus for numerous reasons. This work leverages well-known nonlinear programming techniques to alleviate the non-smoothness caused by degenerate eigenvalues such that topology optimization problems can be solved with the open-source IPOPT software. A fully-vectorial plane wave expansion technique is used with an iterative eigensolver to efficiently predict dispersion properties of candidate structures. Nonlinear programming is employed to solve the inverse problem of designing three-dimensional periodic structures that exhibit complete two-dimensional (2D) and three-dimensional (3D) photonic bandgaps. Mesh refinement is performed to alleviate the large computational burden of designing and analyzing photonic crystals, and a periodic density filter is implemented to impose a minimum feature size for manufacturability considerations.

97 MATHEMATICS AND COMPUTING↗

AN OVERVIEW OF PLASMA PROCESSING OF SRF CAVITIES AT JLAB

Plasma processing is a common technique where the free oxygen produced in a low-pressure RF plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient of the treated surfaces. Jefferson Lab has an ongoing R&D program in plasma processing. The experimental program investigated processing using argon/oxygen and helium/oxygen gas mixtures. The initial focus of the effort was processing C100 cavities by injecting RF power into the HOM coupler ports. We also developed the methods for establishing a plasma C75 cavities where the RF power is injected via the fundamental power-coupler. As part of the process development we processed, three C100 cryomodules in our off-line cryomodule test facility. In May 2023 we processed four C100 cryomodules in-situ in the CEBAF accelerator with the cryomodules returning to an operational status in Sept. 2023. The cumulative improvement in field emission free operation, as measured on a cavity by cavity basis, was 59 MeV or 24%. We recently started processing 7 cryomodules in the CEBAF accelerator in August 2024. Methods systems and results from processing cryomodules and individual cavities in the vertical test will be presented. Current status and future plans will also be presented.

Ganey, Tiffany↗

Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators

This is the final report on the DOE grant number DE-FG02-92ER40727 titled, “Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators.” During this grant period the UCLA program on Advanced Plasma Based Accelerators, headed by Professor C. Joshi has made many key scientific advances and trained a generation of students, many of whom have stayed in this research field and even started research programs of their own. In this final report however, we will focus on the last three years of the grant and report on the scientific progress made in each of the four tasks listed under this grant. Four tasks are focused on: Plasma Wakefield Accelerator Research at FACET, SLAC National Accelerator Laboratory, In House Research at UCLA’s Neptune and 20 TW Laser Laboratories, Laser-Wakefield Acceleration (LWFA) in Self Guided Regime: Experiments at the Callisto Laser at LLNL, and Theory and Simulations. Major scientific results have been obtained in each of the four tasks described in this report. These have led to publications in the prestigious scientific journals, graduation and continued training of high quality Ph.D. level students and have kept the U.S. at the forefront of plasma-based accelerators research field.

43 PARTICLE ACCELERATORS↗

Documentation for DOE/SC/NP Quadrennial Low Energy Nuclear Physics (LENP) Review

Research at LLNL is primarily directed towards satisfying its principal missions in international security, fusion energy, and US nuclear security. Towards this end, a core LLNL strategy has been to advance fundamental scientific understanding to succeed in its purpose, and to recruit and develop a skilled workforce for the future. Research conducted in the Physics Division at LLNL is primarily focused on bringing the highest quality science to bear on LLNL programs to achieve broad success in its overall mission. In this regard, the ―applied-science‖ missions at LLNL are actually quite well-aligned with the fundamental-science research aims of the Office of Science. We aim to perform research for DOE/SC/NP at LLNL that has the greatest leverage towards answering fundamental problems in nuclear science -- both at the forefront of fundamental science and important to the nation’s security. Towards this end, LLNL brings unique capabilities, resources, and skills to bear on the most scientifically challenging endeavors of the DOE/SC/NP mission and enhances the training of the nuclear science workforce in general. LLNL is a world leader in cost-effective high-performance computing, has a broad collection base for Laboratory Directed Research and Development (LDRD), and an excellent track record in solving multi-disciplinary and engineering problems.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

UCLA Tokamak Program Close Out Report

The results of UCLA experimental fusion program are summarized. Starting with smaller devices like Microtor, Macrotor, CCT and ending the research on the large (5 m) Electric Tokamak. CCT was the most diagnosed device for H-mode like physics and the effects of rotation induced radial fields. ICRF heating was also studied but plasma heating of University Type Tokamaks did not produce useful results due to plasma edge disturbances of the antennae. The Electric Tokamak produced better confinement in the seconds range. However, it presented very good particle confinement due to an "electric particle pinch". This effect prevented us from reaching a quasi steady state. This particle accumulation effect was numerically explained by Shaing's enhanced neoclassical theory. The PI believes that ITER will have a good energy confinement time but deleteriously large particle confinement time and it will disrupt on particle pinching at nominal average densities. The US fusion research program did not study particle transport effects due to its undue focus on the physics of energy confinement time. Energy confinement time is not an issue for energy producing tokamaks. Controlling the ash flow will be very expensive.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Precision Studies of Hadronic and Electro-Weak Interactions for Collider Physics (Final Report)

This project was directed toward developing precision computational tools for proton collisions at the Large Hadron Collider, focusing primarily on electroweak boson production and electroweak radiative corrections. The programs developed under this project carried the name HERWIRI, for High Energy Radiation With Infra-Red Improvements, and are the first steps in an ongoing program to develop a set of hadronic event generators based on combined QCD and QED exponentiation. HERWIRI1 applied these improvements to the hadronic shower, while HERWIRI2 will apply the electroweak corrections from the program KKMC developed for electron-positron scattering to a hadronic event generator, including exponentiated initial and final state radiation together with first-order electroweak corrections to the hard process. Some progress was also made on developing differential reduction techniques for hypergeometric functions, for application to the computation of Feynman diagrams.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Plasmonic Control of Radiation and Absorption Processes in Semiconductor Quantum Dots

This document reviews a research program funded by the DOE Office of Science, which has been focused on the control of radiation and absorption processes in semiconductor photonic materials (including III-nitride quantum wells and quantum dots), through the use of specially designed metallic nanoparticles (NPs). By virtue of their strongly confined plasmonic resonances (i.e., collective oscillations of the electron gas), these nanostructures can concentrate incident radiation into sub-wavelength “hot spots” of highly enhanced field intensity, thereby increasing optical absorption by suitably positioned absorbers. By reciprocity, the same NPs can also dramatically increase the spontaneous emission rate of radiating dipoles located within their hot spots. The NPs can therefore be used as optical antennas to enhance the radiation output of the underlying active material and at the same time control the far-field pattern of the emitted light. The key accomplishments of the project include the demonstration of highly enhanced light emission efficiency as well as plasmonic collimation and beaming along geometrically tunable directions, using a variety of plasmonic excitations. Initial results showing the reverse functionality (i.e., plasmonic unidirectional absorption and photodetection) have also been generated with similar systems. Furthermore, a new paradigm for the near-field control of light emission has been introduced through rigorous theoretical studies, based on the use of gradient metasurfaces (i.e., optical nanoantenna arrays with spatially varying shape, size, and/or orientation). These activities have been complemented by materials development efforts aimed at the synthesis of suitable light-emitting samples by molecular beam epitaxy. In the course of these efforts, a novel technique for the growth of III-nitride quantum dots has also been developed (droplet heteroepitaxy), with several potential advantages in terms of compositional and geometrical control. The results of these studies provide fundamental new understanding of optical processes at the nanoscale, including near-field energy transfer between quantum emitters and photonic nanostructures, dissipation phenomena of plasmonic excitations, and radiation from nanoantennas. Furthermore, they may open the way to entirely new device concepts and applications, in a broad range of disciplines including optoelectronics, sensing, spectroscopy, photovoltaics, and quantum information science. A specific application of particularly strong relevance to the DOE mission is the development of energy efficient LED active materials for solid-state lighting, based on plasmonic enhancement effects.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Next-Generation Performance-Based Regulation: Emphasizing Utility Performance to Unleash Power Sector Innovation

Performance-based regulation (PBR) enables regulators to reform hundred-year-old regulatory structures to unleash innovations within 21st century power systems. An old regulatory paradigm built to ensure safe and reliable electricity at reasonable prices from capital-intensive electricity monopolies is now adjusting to a new century of disruptive technological advances that change the way utilities make money and what value customers expect from their own electricity company. Advanced technologies are driving change in power sectors around the globe. Innovative technologies are transforming the way electricity is generated, delivered, and consumed. These emerging technology drivers include renewable generation, distributed energy resources such as distributed generation and energy storage, demand-side management measures such as demand-response, electric vehicles, and smart grid technologies and energy efficiency (EE). PBR enables regulators to recognize the value that electric utilities bring to customers by enabling these advanced technologies and integrating smart solutions into the utility grid and utility operations. These changes in the electric energy system and customer capacities means that there is an increasing interest in motivating regulated entities in other areas beyond traditional cost-of-service performance regulation. This report addresses best practices gleaned from more than two decades of PBR in practice, and analyzes how those best practices and lessons can be used to design innovative PBR programs. Readers looking for an introduction to PBR may want to focus on Chapters 1-5. Chapters 6 and 7 contain more detail for those interested in the intricate workings of PBR or particularly innovative PBR.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Research in Integrated Assessment Inter-Model Development, Testing and Diagnostics (Final Technical Report)

This is the final report on the second phase (spanning 2013-2018) of a project focused on further establishing an integrated assessment modeling (IAM) community research program on IAM model development, diagnostic testing, and inter-comparisons (PIAMDDI), including multi-model scenario ensemble analyses. The program was dedicated to improving the science of integrated assessment by doing cutting edge research in critical scientific areas of IAM development, and integrating that research with research programs on improved methods for model diagnostics, inter-comparison and ensemble-like analyses. We continued to link this program closely to other climate change research programs in the U.S. and abroad, and to make the work highly transparent, accessible and credible. As anticipated, progress in the scientific research areas informed the model comparison methods development and scenario tasks, and the comparisons and ensemble activities helped set priorities for the research areas.

54 ENVIRONMENTAL SCIENCES↗

Supporting the Nation's Electric Interconnections through Integration of Water into their Long-Term Transmission Planning.

Water is a critical resource in the production of electric power. The purpose of this plan is to extend support to the nation's three electric interconnections toward integrating water issues into their long-range transmission planning. This continued support is at the request of the interconnections. The proposed program leverages prior support as well as that of other similarly focused efforts funded across the Department of Energy (DOE). The effort will utilize a project team lead by Sandia National Laboratories and supported by Argonne National Laboratory, National Renewable Energy Laboratory, and Pacific Northwest National Laboratory. The activities recorded here are meant to provide a menu of potential projects that could be implemented as available resources permit.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Interlaboratory Round Robin Testing of SiC/SiC Composite Tubes

With the objective to develop accident tolerant fuel-clad systems for light water reactors, extensive research and development work is being conducted at different governmental, university and industrial labs. Continuous SiC fiber-reinforced SiC matrix (SiC/SiC) composites is one of the leading candidate materials for replacing the traditional Zr alloy cladding due to its high temperature stability, chemical inertness and stability under neutron irradiation. A rich database on the statistics of the mechanical properties of SiC/SiC composite is much needed to carry out the feasibility studies as well as rigorous analysis of the material’s behavior under normal and off-normal reactor conditions. In addition to the properties database, test standards, which ensure the unbiased characterization of the material, are needed. The mechanical properties database, particularly for tubular SiC/SiC specimens, is limited and standardized test methods are still under development. The current work focuses on filling these gaps through an interlaboratory round robin testing program of SiC/SiC composite tube specimen involving several organizations from academia, government laboratories and industry. The difficulties and issues in the testing were identified and addressed through the ORNL lead test. This report summarizes the current status and forward planning on the interlaboratory study.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Development of a Reference Governor-based Control Scheme for Integrated Energy Systems

The concept of an Integrated Energy System (IES) is meant to combine different energy technologies in synergistic ways to achieve a more secure and economical energy supply. The RAVEN-based HYBRID framework is used to find the optimal installed capacity and the optimal economical dispatch of each component of the IES. In practice what is achievable is limited by not only the inherent physical response characteristics of individual plant units but also by equipment operating limits. The inherent response characteristics are presently accounted for in the RAVEN-based HYBRID framework by dynamic models for plant units. The equipment operating limits, which are not yet addressed in HYBRID, are the subject of this report. These limits are set to achieve a design service life for a plant unit and are based on material degradation in the presence of mechanical fatigue induced by thermal cycling and by structure creep resulting from elevated temperature conditions. In general, the plant unit designer determines and specifies the allowable operating range of key process variables. It is then up to the integrated system design engineer to ensure those conditions are met. This can be accomplished through a combination of limiting the demand rates made on the plant unit and designing a control system that limits variations of key process variables. The typical control system design procedure, however, is not well suited for achieving this for complex dynamic systems such as encountered in integrated energy systems where multiple plant units must be simultaneously coordinated. This report describes how equipment operating limitations in an IES can be formally met through a control system design procedure know as the Reference Governor. The approach augments the existing controllers in a plant unit with an advance controller that modifies the issued setpoints so that selected process variables remain within limits. The design procedure is applied to the reference multi-unit system that has been the focus of Modeling and Simulation task in the Integrated Energy System program. Results describing application to the problem of limiting key process variables during operational transients for two of the plant units, the balance of plant and the gas turbine, are then presented. It is demonstrated that the Reference Governor method is an effective means for ensuring equipment operating constraints can be met in an IES. The software that implements the method has been made accessible to others on the Modeling and Simulation upload site.

42 ENGINEERING↗

Sandia's Research in Support of COVID-19 Pandemic Response: Computing and Information Sciences

This report summarizes the goals and findings of eight research projects conducted under the Computing and Information Sciences (CIS) Research Foundation and related to the COVID- 19 pandemic. The projects were all formulated in response to Sandia's call for proposals for rapid-response research with the potential to have a positive impact on the global health emergency. Six of the projects in the CIS portfolio focused on modeling various facets of disease spread, resource requirements, testing programs, and economic impact. The two remaining projects examined the use of web-crawlers and text analytics to allow rapid identification of articles relevant to specific technical questions, and categorization of the reliability of content. The portfolio has collectively produced methods and findings that are being applied by a range of state, regional, and national entities to support enhanced understanding and prediction of the pandemic's spread and its impacts.

59 BASIC BIOLOGICAL SCIENCES↗

Sensitivity and Uncertainty Analysis of Generator Failures under Extreme Temperature Scenarios in Power Systems

This report summarizes work done under the Verification, Validation, and Uncertainty Quantification (VVUQ) thrust area of the North American Energy Resilience Model (NAERM) Program. The specific task of interest described in this report is focused on sensitivity analysis of scenarios involving failures of both wind turbines and thermal generators under extreme cold-weather temperature conditions as would be observed in a Polar Vortex event.

17 WIND ENERGY↗

Policy and Regulatory Environment for Utility-Scale Energy Storage: Bangladesh

Bangladesh has experienced significant economic growth and poverty reduction over the past several decades. Recognizing the central role electricity plays in economic development, the Government of Bangladesh (GOB) has established policies to accelerate the growth of the electric power sector. The Bangladesh power grid is transforming into one marked by declining reliance on domestic natural gas reserves and oil-based rental power plants, increasing renewable energy contribution, and shifting demand patterns. The GOB is now reconsidering its prior plans to increase the share of coal capacity in the generation mix to meet demand, shifting its focus instead to electricity imports from neighboring countries, nuclear generation, liquified natural gas imports, and domestic renewable resources such as wind and solar. However, investments in the transmission and distribution system, as well as ancillary services, have not kept pace with investments in generation resources over the past decade. Thus, Bangladesh electricity consumers still experience outages and poor power quality despite adequate installed capacity. On the demand side, population growth and industrialization have fueled steady growth in electricity consumption as efforts to expand access to electricity enabled near-universal electricity access by mid-2020. The combined changes in the mix of generation resources and patterns of electricity demand present new challenges and opportunities in operating and maintaining a reliable power system. Energy storage has the potential to help meet these challenges and accelerate Bangladesh’s energy transition. Declining costs for some energy storage technologies make them increasingly cost-effective solutions to provide a wide range of grid services. Previous analyses of energy storage in the region have identified several potential applications for storage at the bulk system level, including energy arbitrage, ancillary services, and transmission network support. The potential for storage to meet these needs depends on many factors, including physical characteristics of the power system and the policy and regulatory environments in which these energy storage assets would operate. This report applies an Energy Storage Readiness Assessment the National Renewable Energy Laboratory developed for policy makers and regulators to identify priority areas of focus as they continue to develop the appropriate suite of policies, programs, and regulations to enable storage deployment. This assessment uses a simple evaluation scheme to identify the barriers and opportunities for utility-scale energy storage within Bangladesh’s policy and regulatory environment.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Summer 2021 Internship Report

The internship was a 12 week program which started on 7th of June 2021. During this internship program, I worked as a Research Intern on a project which focused on feature extraction from scientific PDF documents using open-source, machine-learning-based tools.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗