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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 127 records · Page 7

Energy Exascale Earth System Model v2.1.0

First release of version 2.1 of the Energy Exascale Earth System Model. [ATM] The atmosphere component remains EAM. There are no major changes in the default configuration since 2.0. New features include: A semi-lagrangian tracer transport for theta-l dycore, a new algorithm for finding the tropopause, new RRM mesh configurations. Add and update SSP370 and SSP585 cases. Restore the FIDEAL case. [LAND] The land component is ELM. There are no major changes in the default configuration since 2.0. Several option features have been added including: implementation of topography-based subgrid structure (topounits) and accompanying parameterizations and atmospheric forcing downscaling methods; a new plant hydraulics scheme; two-way land-river hydrological coupling through the infiltration of floodplain water; an implementation of perennial crops; updates to the SNICAR-AD snow radiative transfer model; and implementation of soil erosion and sediment yield in ELM-Erosion. Each of these new changes is modular in design and can be turned on or off as the user specifies; they are currently being tested in different “BGC” configurations. [OCEAN] The ocean component remains MPAS-Ocean. Major change since version 2.0 include the addition of the Fox-Kemper et al. 2011 parameterization for submesocale eddies, a correction for barotropic thickness consistency that reduces divergence noise, and the addition of an ocean carbon conservation analysis member. [SEAICE] The sea-ice component remains MPAS-Seaice. Major changes since version 2.0 include: A correction to how shortwave parameters are interpolated in the snicar-ad 5-band radiation scheme, the addition of a sea ice carbon conservation analysis member, updates to the default sea ice biogeochemistry namelist parameters to be consistent with version 2.0 improvements to nitrogen cycling and a correction in the ice-ocean dissolved organic nitrogen coupling. [LAND ICE] The land-ice component remains MPAS-Albany-landIce (MALI). Major changes since 2.0 include an update to the MALI version and the Greenland mesh.[RIVER] The river model is MOSART. There are no major changes in the default configuration since 2.0. A major new optional feature is two-way river-ocean hydrological coupling between MOSART and MPAS-O. This change can be turned on or off as the user specifies, and is being tested in different configurations. [COUPLER] The coupler remains cpl7/MCT. Major changes since version 2.0 include: Carbon budget calculated when heat/water budgets active. Fix a bug in land-atm fluxes for tri-grid configurations. [OTHER] a small bug in the zenith angle calculation was fixed in the data models.

ECP↗

Side-lobe reduction by cascading Bragg grating filters on a Si-photonic chip

Bragg-grating based cavities and coupler designs present opportunities for flexible allocation of bandwidth and spectrum in silicon photonic devices. Integrated silicon photonic devices are moving toward mainstream, mass adoption, leading to the need for compact Bragg grating based designs. In this work we present a design and experimental validation of a cascaded contra-directional Bragg-grating coupler with a measured main lobe to side-lobe contrast of 12.93 dB. This level of performance is achieved in a more compact size as compared to conventional apodized gratings, and a similar design philosophy can be used to improve side-lobe reduction in grating-based mirror design for on-chip lasers and other cavity-based designs as well.

42 ENGINEERING↗

NGEE Arctic Integrated Modeling (IM3): Improved snow-vegetation interaction

This data product represents the integration of new code capability for arctic tundra snow-vegetation-terrain interactions into the Energy Exascale Earth System Model (E3SM), through the E3SM Land Model (ELM) component. This code integration is the result of collaborative effort between the NGEE Arctic project and the E3SM project. The NGEE Arctic project developed a total of six Integrated Modeling (IM) modules informed by observations and experiments. New ELM capability represented by this data product (IM3) falls into three categories: 1) Downscaling from gridcell to topographic unit level when working through the existing coupler bypass code. 2) Four new parameters (taper, stocking, bendresist, and vegshape) have been added to ELM to allow for flexible definition of snow-vegetation interactions. 3) Vegshape and bendresist parameters are used to calculate the fraction of leaf area and/or stem area buried by snow for a given snow depth. This data record consists of a single document (pdf format) that describes the theoretical basis for the snow-vegetation-terrain interactions added to ELM, and describes the modifications made to the ELM code. The Methods section of this metadata record includes a link to the public E3SM code repository where the exact code modifications as integrated in E3SM can be accessed. The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

Thornton, Peter E [ORNL] (ORCID:0000000247595158)↗

Status of PIP-II 650 MHz Prototype Dressed Cavity Qualification

Low-beta and high-beta sections of PIP-II linac will use nine low-beta cryomodules with four cavities each and four high-beta cryomodules with six cavities each. These cavities will be produced and qualified in collaboration between Fermilab and the international partner labs. Prior to their installation into prototype cryomodules, several dressed cavities, which include jacketed cavities, high power couplers, and tuners, will be qualified in STC horizontal test bed at Fermilab. After qualification of bare β = 0.9 cavities at Fermilab, several pre-production β = 0.92 and β = 0.61 cavities have been and are being fabricated and qualified. Procurements have also been started for high power couplers and tuners. In this contribution we present the current status of prototype dressed cavity qualification for PIP-II.

43 PARTICLE ACCELERATORS↗

In Situ Plasma processing of SRF cuperconducting cavities at JLAB, 2024 Update

Jefferson Lab has an ongoing R&D program in plasma processing. The experimental program investi-gated processing using argon/oxygen and heli-um/oxygen gas mixtures. Plasma processing is a com-mon technique where the free oxygen produced by the plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient. The initial focus of the effort was processing C100 cavities by injecting RF power into the high order mode (HOM) coupler ports. We also developed the methods for establishing a plasma in C75 cryomodules where the RF power is injected via the fundamental power-coupler. Four C100 cryomodules were in situ processed in the CE-BAF accelerator in May 2023 with the cryomodules returning to an operational status in Sept. 2023. The overall operational energy gain for the four cryomod-ules was 49 MeV. Methods, systems and results from processing cryomodules in the CEBAF accelerator and vertical test results are presented. Current status and future plans are discussed.

Powers, T.↗

Design of a 1.3 GHz RF-Dipole Crabbing Cavity for International Linear Collider

The International Liner Collider (ILC) requires crabbing systems to increase the luminosity of the colliding electron and positron bunches. There are several frequency options for the crabbing cavity. We have designed a 1.3 GHz compact 1-cell and 2-cell rf-dipole crabbing cavity to compensate for luminosity degradation due to large crossing angle. This paper presents the 1-cell and 2-cell cavities designed to meet the current specifications including the fundamental power coupler and higher order mode couplers.

De Silva, S.U.↗

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↗

Improvements to LCLS-II Cryomodule Transportation

The Linear Coherent Light Source (LCLS-II) is currently being constructed at the SLAC National Laboratory. A total of 35 cryomodules will be fabricated at Jefferson Lab (JLab) in Virginia and Fermi National Laboratory (FNAL) in Illinois and transported via road to SLAC. A shipping frame with an inner bed isolated by springs was designed to protect the CMs from shocks and vibrations during shipments. Successful road testing of the JLab prototype paved the way for production CM shipments. The initial production shipments lead to several catastrophic failures in beamline vacuum in the cryomodules. The failures were determined to be due to fatigue in Fundamental Power Coupler (FPC) bellows due to excessive motion during shipment. A series of instrumented CM shipping tests and component tests were undertaken to develop a solution. A modified spring layout was tested and implemented, which reduced shocks on the CMs. FPC coupler bellows restraints were tested on a shaker table and on a CM during shipping; they were able to reduce bellows motion by a factor of three. The updated shipping system is currently in use and has successfully delivered six cryomodules to SLAC from JLab and FNAL.

43 PARTICLE ACCELERATORS↗

Direct Coupled Gyrotron for Plasma Heating. Phase II Final Report

This program was tasked with rebuilding an existing gyrotron with a direct ouput coupler. The direct coupler section was built and tested. The program also build an new electron gun and output window. Most subassemblies were completed for a new collector. This report describes the testing and fabrication of components. Unfortunately, issues with the collector assembly depleted funds before the program could be completed. Additional funds will be required to complete the collector and rebuild and test the gyrotron.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

High-Power Oak Ridge Converter (ORC) for Extreme Fast Charging Applications

This project report presents a novel power converter system called Oak Ridge Converter (ORC), a patented technology developed by the Oak Ridge National Laboratory (ORNL) for XFC wireless EV charging systems. ORC integrates the grid interface converter (also known as the active front-end rectifier with power factor correction) with the high-frequency inverter stage, promoting size and cost-effective charging technology with reduced infrastructure costs. The integration of the front-end rectifier with the high-frequency inverter truly eliminates one power conversion stage and achieves more than 33% size, weight, volume, and cost reduction on the wireless charging systems. Furthermore, ORC eliminates the primary side direct current (DC) bus bulk capacitors that are usually aluminum electrolytic capacitors and replaces them with very small, cost-effective, highly reliable, and high-temperature operation-capable alternate current (AC) film capacitors. ORC is also applicable to both single-phase and poly-phase couplers. When used with polyphase couplers, ORC further improves the power density of the overall system with higher power density power electronics. Moreover, ORC is inherently bidirectional and allows the system to provide power back to the grid for grid ancillary or grid support services. The ORC, based on a patented ORNL technology, is an excellent approach to resolving the high-power charging problems as described above, which directly converts the 60 hertz (Hz) line frequency into high frequency (i.e., 85 kilohertz (kHz)) to use with a high-frequency isolation transformer or wireless charging coils while eliminating the primary side number of power conversion stages from two to one. The result of the project is a prototype and reference design for a high-power wireless charging system—including power electronics, magnetics, and thermal—serving as a baseline for product development. The proposed system results are demonstrated for 270 kW of output power, with the system's overall efficiency of 92% from the AC grid, achieving less than 3% current total harmonic distortion (THD) and around 0.99 power factor (PF).

33 ADVANCED PROPULSION SYSTEMS↗

Misalignment Tolerant Three-phase Wireless Fast Charging System for Electric Vehicles

This project proposes improving the technology level of the three-phase wireless charging technology developed at Oak Ridge National Laboratory (ORNL). Successful commercialization of wireless charging systems require that they meet strict safety standards for electromagnetic field emissions and interoperability with other wireless charging technology. ORNL has previously demonstrated a 50kW three-phase wireless power transfer system with 95% efficiency. This prototype system weighed less than 50% of similar high-power wireless charging system while simultaneously exhibiting better safety characteristics. Due to better material utilization, the reduction in mass is expected to translate into similar cost reduction for the magnetic coupler. Additionally, the smaller footprint of the system can ease vehicle integration difficulties that would be encountered using other technology. Furthermore, the three-phase design can be made to operate with existing single-phase coupler design more easily and without intentional physical misalignment which would otherwise pose safety issues.This project developed ORNL’s WPT technology to satisfy the specifications and requirements for electric vehicle (EV) charging. The result of the project will be a prototype and reference design for a high-power wireless charging system—including magnetics, power electronics, and controls—serving as a baseline for product development.

33 ADVANCED PROPULSION SYSTEMS↗

Strongback Validation in Compact Particle Accelerator

To achieve superconductivity, RF cavities must operate under cryogenic conditions. These low temperatures cause thermal shrinkage, posing a challenge in maintaining the position of the RF coupler, a vital component of the particle accelerator. The solution to this issue includes a passive design that minimizes heat transfer to the cavity while also withstanding loads encountered during transport. A mock-up was constructed to demonstrate the effectiveness of the solution in maintaining proper RF coupler alignment under thermal contraction. The results confirm the feasibility of the design for maintaining operational integrity during cryogenic conditions.

Jakopin, Alexander [Northern Illinois U.]↗

Misalignment Tolerant Three-phase Wireless Fast Charging System for Electric Vehicles

This project proposes improving the technology level of the three-phase wireless charging technology developed at Oak Ridge National Laboratory (ORNL). Successful commercialization of wireless charging systems require that they meet strict safety standards for electromagnetic field emissions and interoperability with other wireless charging technology. ORNL has previously demonstrated a 50kW three-phase wireless power transfer system with 95% efficiency. This prototype system weighed less than 50% of similar high-power wireless charging system while simultaneously exhibiting better safety characteristics. Due to better material utilization, the reduction in mass is expected to translate into similar cost reduction for the magnetic coupler. Additionally, the smaller footprint of the system can ease vehicle integration difficulties that would be encountered using other technology. Furthermore, the three-phase design can be made to operate with existing single-phase coupler design more easily and without intentional physical misalignment which would otherwise pose safety issues. This project developed ORNL’s WPT technology to satisfy the specifications and requirements for electric vehicle (EV) charging. The result of the project will be a prototype and reference design for a high-power wireless charging system—including magnetics, power electronics, and controls—serving as a baseline for product development.

33 ADVANCED PROPULSION SYSTEMS↗

Robotic Assembly of SRF Cavity Pair

Superconducting Radio Frequency (SRF) cavities for particle accelerators require tight tolerances, ultrahigh vacuum, and strict cleanliness during assembly. As in the semiconductor industry, defects such as particles and residues are deleterious to performance, possibly rendering a cavity unfit for use. This problem is addressed primarily through cleanroom assembly during sensitive steps and rigorous chemical processing to prevent and remove such defects. Human workers are often the largest source of contamination, even with proper gowning and practices. The semiconductor industry has long integrated robots in cleanroom operation, but this has not occurred for SRF cavity production; SRF cavities, unlike wafers, are complex shapes, require more hands-on mechanical assembly, and are low-volume production items. At Jefferson Laboratory, a co-operative robot (cobot) has been setup to overcome these problems. Cobots are safe for use alongside human workers and can integrate new tools such as a 3D camera part detection and gripper for item manipulation. Therefore, cobots represent a promising avenue for reducing particulate generated during a variety of assembly tasks. A mockup of a cavity pair and coupler was setup and the cobot programmed to automatically pick up the coupler and place on the mating cavity flange. Particle counting methods were setup to measure human vs cobot assembly particulate generation inside a cavity mockup. Other potential uses will be discussed for further improving SRF cavity assembly steps, where a cobot can replace or assist a human operator, and what potential gains are expected.

Duzik, Adam [Thomas Jefferson National Accelerator↗

Improvements for LCLS-II Cryomodule Transportation

The Linear Coherent Light Source (LCLS-II) is currently being constructed at the SLAC National Laboratory. A total of 35 cryomodules will be fabricated at Jefferson Lab (JLab) in Virginia and Fermi National Laboratory (FNAL) in Illinois and transported via road to SLAC. A shipping frame with an inner bed isolated by springs was designed to protect the CMs from shocks and vibrations during shipments. Successful road testing of the JLab prototype paved the way for production CM shipments. The initial production shipments lead to several catastrophic failures in beamline vacuum in the cryomodules. The failures were determined to be due to fatigue in Fundamental Power Coupler (FPC) bellows due to excessive motion during shipment. A series of instrumented CM shipping tests and component tests were undertaken to develop a solution. A modified spring layout was tested and implemented, which reduced shocks on the CMs. FPC coupler bellows restraints were tested on a shaker table and on a CM during shipping; they were able to reduce bellows motion by a factor of three. The updated shipping system is currently in use and has successfully delivered six cryomodules to SLAC from JLab and FNAL.

Huque, N. A.↗

Selectively adjustable interface assembly

A system includes a first component, a second component, a locking pin, and an interface assembly that is configured to selectively adjust a stiffness of a coupling interface between the first component and the second component. The interface assembly includes at least one support coupler secured to the first component. The support coupler(s) includes a main body, a first arm extending from a first side of the main body, a second arm extending from a second side of the main body, and a flange extending from the main body. The flange includes a locking pin hole that is configured to selectively receive the locking pin. The locking pin is selectively moveable between a retracted position in which the locking pin is out of the locking pin hole, and a deployed position in which the locking pin extends into the locking pin hole and a portion of the first component and locks the interface assembly to the first component.

42 ENGINEERING↗

Gas sensor including optic fiber connector

A gas detector sensor node includes a first sensor conductor having a terminal end, a second sensor conductor including an end section, and a coupler joining the terminal end of the first sensor conductor with the end section of the second sensor conductor. The coupler is permeable to gas.

Karp, Jason Harris↗