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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 1,603 records · Page 89
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Experimental evaluation of localized creep deformation in grade 91 steel weldments

Spatially resolved measurement of localized creep deformation in heterogeneous creep resistant steel weldments is crucial but challenging for lifetime assessments of critical steam components in power plants. Here, experimental approaches were established to quantitatively evaluate commonly observed localized creep deformation in multi-pass Grade 91 steel weldments. An in-situ digital image correlation (DIC) system was utilized with a creep testing frame to monitor and measure both full-field strain and localized strain accumulation across the weldments during long-term creep testing at elevated temperatures. The in situ DIC method measured not only the creep deformation behavior of the weld metal, heat affected zone (HAZ), and base metal, but also creep strain evolution for each sub-region within the HAZ itself, including coarse-grained HAZ, fine-grained HAZ (FGHAZ), and intercritical HAZ (ICHAZ). The DIC results revealed that local creep strain in the ICHAZ reached up to 90% strain before final rupture, whereas nominal creep strain measured by the standard extensometer of the tested cross-weld specimen was below 10%, indicative of Type IV cracking of the Grade 91 weld. Microstructural analyses revealed that the faster creep degradation/deformation in the HAZ was caused mainly by accelerated matrix grain recrystallization/growth and a reduced pinning effect from the segregated and coarsened precipitates in the FGHAZ and ICHAZ. The ultimate creep rupture occurred in the ICHAZ owing to its lowest creep resistance induced by the largest recrystallized grain size, the lowest fraction of coincidence site lattice, and the lowest local strain energies/dislocation densities.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Design of a Transport System for the PIP-II HB650 Cryomodule

The PIP-II Project at FNAL requires the assembly of 3 high-beta 650MHz cryomodules at STFC Daresbury (DL) in the UK. These modules must be safely transported from DL to FNAL in the USA. Previous experience with cryomodule transport was leveraged at both labs to design a transport system to protect the cryomodules during transit. Requirements for the system included mitigation of shocks, drops, and vibrations, and acting as a lifting fixture. It is comprised of a tessellated steel frame which encompasses the module with a wire rope isolator arrangement which the module mounts to. The frame was designed to withstand the weight of the 12.5 tonne cryomodule in various load cases. Details of shock and vibration profiles were obtained from MIL-STD-810H and were used to guide the sizing of the isolators. The frame and the isolation system were analysed via FEA using the shock and vibration profiles as an input. The transport system was found to be suitable for the given isolation, frame stiffness, and lifting code requirements. The frame has been fabricated and successfully load tested at FNAL. It will now be road tested with a dummy cryomodule before undergoing a trial run to DL.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Testing and Processing of Pre-production 325 MHz Single Spoke Resonator Power Couplers for PIP-II Project

Fundamental 325 MHz power couplers are designed, built and tested for SSR cavities in PIP-II project. Couplers should work in CW mode at power level 7.5kW w/o beam and ~15 kW with the 2 mA beam. At pre-production stage we built and tested 6 couplers, produced by CPI (FNAL) and PMB (IJCLab) and 4 more couplers will be tested soon. Two of tested couplers had TiN coated ceramic window. In warm test stand two couplers were mounted on the coupling chamber and tested in SW regime at full reflection with phase controlled by position of short and reflection insert. Couplers were tested at pulse mode (up to 25kW) and cw mode (12kW) with HV bias or without bias. Test results demonstrated that 3.5 kV DC bias completely suppresses multipactor in coupler. Vacuum activity in coupler was controlled by e-pickups and build-in vacuum gauges, located near the vacuum side of window. Power processing without DC bias was done for several couplers with and without TiN coating on ceramic window. Test results are presented and discussing in paper.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Analysis of the performance of a hybrid CPU/GPU 1D2D coupled model for real flood cases

Coupled 1D2D models emerged as an efficient solution for a two-dimensional (2D) representation of the floodplain combined with a fast one-dimensional (1D) schematization of the main channel. At the same time, high-performance computing (HPC) has appeared as an efficient tool for model acceleration. In this work, a previously validated 1D2D Central Processing Unit (CPU) model is combined with an HPC technique for fast and accurate flood simulation. Due to the speed of 1D schemes, a hybrid CPU/GPU model that runs the 1D main channel on CPU and accelerates the 2D floodplain with a Graphics Processing Unit (GPU) is presented. Since the data transfer between sub-domains and devices (CPU/GPU) may be the main potential drawback of this architecture, the test cases are selected to carry out a careful time analysis. Here, the results reveal the speed-up dependency on the 2D mesh, the event to be solved and the 1D discretization of the main channel. Additionally, special attention must be paid to the time step size computation shared between sub-models. In spite of the use of a hybrid CPU/GPU implementation, high speed-ups are accomplished in some cases.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Rapid Quality Assessment in Additive Manufacturing: New Procedure Accelerates Build Quality Assessment. White paper

Accelerated growth of the additive manufacturing (AM) industry in recent years is accompanied by a rising need for methods to quickly assess quality at-scale. Current practices for quality inspection include nondestructive test methods and destructive testing of witness coupons, which are artifacts built alongside the actual part. However, these methods can be costly and time-consuming. Recognizing this need, the Additive Manufacturing Center of Excellence (AM CoE) initiated a project led by its partner, Auburn University, to develop rapid testing procedure using asbuilt samples tested in torsion to quantitatively assess build quality. The presented work developed a rapid testing procedure using as-built samples tested in torsion to quantify small variances for assessing build quality.

42 ENGINEERING↗
DOE OSTI2022

NorthStar Facility Target Fab and Flow Testing - FY 21

The facility target fabrication and flow testing activity will consist of flow tests using the blower system at LANL to test the disk holder and target, both redesigned by the NorthStar prime contractor. The housing and transition system delivering helium cooling to the disc holder and target will be fabricated and tested at LANL facilities. The tests will include pressure drop versus flow measurements through the target and housing, optical flow diagnostics and fiber optic imaging of the disc stack. The pressure drop measurements will be compared to CFD simulations to verify the latter, the optical flow diagnostics will be used to determine whether modifications made to the housing and target holder allow sufficient flow through the bottom of the housing to adequately cool it and the fiber optics will be used to image the discs during operation as a proof of concept of the diagnostic, to be used at NorthStar facilities during preproduction testing. The work is a Partial Fulfillment of the Deliverable Requirement for NorthStar Facility Target Fab and Flow Testing and Production Target Testing Support by LANL

42 ENGINEERING↗
DOE OSTI2023

Production of Precursor Materials for the Development of Iron-Based Superconductor (IBS) Wire

The objective of the activities under this Annex is to address the extrinsic Jc limitations uncovered in pioneering work. In order to engineer the defects pinning landscape charged particle irradiations experiments on bulk samples, different doping and chemical additions will be performed at different National facilities (Test Beam Facility at Fermilab; Linac Isotope Producer at Brookhaven National Laboratory; Integrated Biology Laboratory at University of Wisconsin-Madison; Facility for Rare Isotope Beams at Michigan State University). The samples will be produced at ENEA by different techniques. Magnetization and advanced microscopy measures will be performed at Fermilab. After irradiation, depending on the level of radioactivity, the samples will be tested at Fermilab or where it is possible to measure radioactive materials as University of Wisconsin-Madison.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

VSR SRF HOM load and waveguide

Under the expired ICRADA JSA2012S015 mod 5, JLab collaborated with HZB to design and prototype the high power HOM load for HZB VSR upgrade 1.5GHz cavities and bERLinpro cavities, as well as the optimization of the HOM waveguide thermal design. The scope of work to be contracted with this ICRADA includes: finalize the HZB VSR HOM load design for production; fabricate, test and deliver 30 HOM loads to HZB; design and prototype the HZB VSR HOM waveguide assembly.

43 PARTICLE ACCELERATORS↗
DOE OSTI2026

Testing the Common Platform LLRF with a 197 MHz NCRF Cavity

The Common Platform is the hardware that will support the new LLRF platform to be used for the Electron-Ion Collider. The Common Platform features a carrier board that is used to interface with a variety of daughter for different applications. This paper details the testing that was done using the Common Platform and an RF Digitizer Daugther Board. Firstly, the firmware and software development is discussed followed by a description of the controls algorithms used in the testing. Then, testing and verification of the platform with a 197 MHz NCRF cavity is discussed. The paper concludes with results from the testing and the path forward.

42 ENGINEERING↗
DOE OSTI2023

Utilization of Additive Manufacturing for the Rapid Prototyping of C-Band Radiofrequency Loads

Additive manufacturing is a versatile technique that shows promise in providing quick and dynamic manufacturing for complex engineering problems. Research has been ongoing into the use of additive manufacturing for potential applications in radiofrequency (RF) component technologies. Here, we present a method for developing an effective prototype load produced from 316L stainless steel on a direct metal laser sintering machine. The model was tested using simulation software to verify the validity of the design. The load structure was manufactured by an online digital manufacturing company, showing the viability of using easily accessible tools to manufacture RF structures. The produced load was able to produce an S11 value of −22.8 dB at a C-band frequency of 5.712 GHz while under a vacuum. In a high-power test, the load was able to terminate a peak power of 8.1 MW. The discussion includes future applications of the present method and how it will help to improve the implementation of future accelerator concepts.

36 MATERIALS SCIENCE↗
DOE OSTI2022

γ-Ray Emission from Classical Nova V392 Per: Measurements from Fermi and HAWC

This paper reports on the γ -ray properties of the 2018 Galactic nova V392 Per, spanning photon energies ~0.1 GeV–100 TeV by combining observations from the Fermi Gamma-ray Space Telescope and the HAWC Observatory. As one of the most rapidly evolving γ -ray signals yet observed for a nova, GeV γ -rays with a power-law spectrum with an index Γ = 2.0 ± 0.1 were detected over 8 days following V392 Per’s optical maximum. HAWC observations constrain the TeV γ -ray signal during this time and also before and after. We observe no statistically significant evidence of TeV γ -ray emission from V392 Per, but present flux limits. Tests disfavor the extension of the Fermi Large Area Telescope spectrum to energies above 5 TeV by 2 standard deviations (95%) or more. We fit V392 Per’s GeV γ -rays with hadronic acceleration models, incorporating optical observations, and compare the calculations with HAWC limits.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

$\mathrm{SageNet}$: Fast Neural Network Emulation of the Stiff-amplified Gravitational Waves from Inflation

Accurate modeling of the inflationary gravitational waves (GWs) requires time-consuming, iterative numerical integrations of differential equations to take into account their backreaction on the expansion history. To improve computational efficiency while preserving accuracy, we present the Stiff-amplified Gravitational-wave Emulator Network (SageNet), a deep learning framework designed to replace conventional numerical solvers (code available at https://github.com/YifangLuo/SageNet). SageNet employs a long short-term memory architecture to emulate the present-day energy density spectrum of the inflationary GWs with possible stiff amplification, Ω GW (f). Trained on a data set of 25,689 numerically generated solutions, SageNet allows accurate reconstructions of Ω GW (f) and generalizes well to a wide range of cosmological parameters; 90.9% of the test emulations with randomly distributed parameters exhibit errors of under 4%. In addition, SageNet demonstrates its ability to learn and reproduce the artificial, adaptive sampling patterns in numerical calculations, which implement denser sampling of frequencies around changes in spectral indices in Ω GW (f). The dual capability of learning both physical and artificial features of the numerical GW spectra establishes SageNet as a robust alternative to exact numerical methods. Finally, our benchmark tests show that SageNet reduces the computation time from tens of seconds to milliseconds, achieving a speedup of ∼10 4 times over standard CPU-based numerical solvers with the potential for further acceleration on GPU hardware. These capabilities make SageNet a powerful tool for accelerating Bayesian inference procedures for extended cosmological models. In a broad sense, the SageNet framework offers a fast, accurate, and generalizable solution to modeling cosmological observables whose theoretical predictions demand costly differential equation solvers.

Astronomy data modeling↗
DOE OSTI2021

Visual HPC Workflows for the Analysis of System Dynamics Models

Visual analytics supported by high performance computing (HPC) accelerates and enhances the discovery, exploration, and analysis of causal patterns in complex system dynamics (SD) models. We present a suite of visualization-assisted ensemble-based techniques for hypothesis generation and testing, and for sensitivity analysis. By employing HPC to provide parallel, on-demand simulation of SD models, one can “steer” an ensemble of simulated scenarios in real time as one first formulates and then informally tests those hypotheses: this provides rapid feedback for analysts to refine their understanding of the causal relationships emergent from a model. Such understandings can be followed and augmented by rigorous application of statistical methods, namely global variance-based sensitivity analysis, Monte-Carlo filtering, adaptive regional sensitivity analysis, and self-organized maps: here timely computation relies on HPC, while effective presentation emphasizes high-dimensional multivariate data visualization. Immersive visualization in virtual 3D environments provides an excellent adjunct to the traditional 2D graphics typically used for SD models, as it generates an embodied understanding of model behavior and facilitates an active, collaborative critique of model structure and output. Finally, we summarize prospects for HPC-enabled visual analytics applied to SD modeling.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

Assessing Customer Experience and Business Models around Price-to-Device Communication and Smart Control Pathways in CalFlexHub

California is facing three major challenges in electrical grid operation: renewable overgeneration, steep evening ramping, and growing peak demand. The state has identified dynamic retail price response as a key strategy evidenced by CPUC’s Dynamic Rates proceeding and CEC’s Load Management Standards. Furthermore, the CEC launched a $16M “California Load Flexibility Research and Deployment Hub (CalFlexHub)” administered by Berkeley Lab to accelerate price-response flexible load technologies in buildings and EV charging. There are more than 16 laboratory and field demonstration projects in CalFlexHub, each demonstrating innovative automated price-response technologies. CalFlexHub tests various pathways through which hourly price signals and triggered control commands are communicated to load-flexible devices such as smart thermostats, heat pumps, water heaters, and EVs. We identified seven unique communication and control pathways, which involve combinations of third-party cloud, device OEM’s cloud, building central gateway, and local controller in between the price server and the load-flexible devices. It is important for utilities and policy makers to understand the long-term implications of each pathway in designing future programs and creating related policies and mandates for market transformation. We propose an evaluation framework including the following aspects: ● Functionality: connectivity and uptime, resilience, and optimization; ● Customer experience: simplicity in setup, troubleshooting support, continuity, customer choice, first cost, and ongoing cost; ● Business model and scalability: advance interoperability, holistic solution, bridge unique gap, customer base, and value streams and pricing structures. In this paper, we identify emerging business models associated with each communication pathway and discuss their positive features and challenges from the above aspects.

Liu, Jingjing↗
DOE OSTI2024

First Results from Two Nb3Sn Cavities Assembled in a CEBAF Quarter Cryomodule

Two 1.5 GHz CEBAF C75-shape 5-cell accelerator cavities were coated with Nb3Sn film using the vapor diffusion technique at Fermilab and Jefferson Lab coating facilities. Both cavities were measured at 4 K and 2 K in the vertical cavity test facility (VCTF) in each lab, then assembled into a CEBAF quarter cryomodule at Jefferson Lab. The cryomodule was tested at 4 K and 2 K in the CryoModule Test Facility (CMTF) at Jefferson Lab. RF test results for both cavities in the cryomodule are similar to those in the qualification test in VTS, with one cavity reaching Eacc = 7.9 MV/m and the other - 13.3 MV/m at 4 K.

Eremeev, G.↗
DOE OSTI2026

Integration and performance of large area picosecond photodetectors in the accelerator neutrino neutron interaction experiment

ANNIE, the Accelerator Neutrino Neutron Interaction Experiment, is a 26-ton Gadolinium-loaded water Cherenkov detector located at the Booster Neutrino beam line at Fermilab to mainly measure neutron multiplicity of neutrino interactions and test the performance of Large Area Picosecond Photodetectors (LAPPD). This thesis presents the integration of LAPPD at ANNIE and the preliminary performance analysis. LAPPDs achieved 2.48ns bunch structure resolution, even considering the time of flight and the intrinsic bunch width. The analysis also achieves better than 100ps intrinsic timing resolution, sub-mm position resolution for a single photoelectron, and cm-level resolution in conditional muon track reconstruction.

Feng, Yue [Iowa State U.] (ORCID:0000000332021351)↗
DOE OSTI2026

Exploring Approaches for Accelerated Mass Spectrometric Detection of Fluorochemicals from Aqueous Solutions Using Indirect, Adsorbent-Facilitated Desorption Ionization

There is a growing need for rapid, low-cost analytical tools to screen water supplies for persistent contaminants. Due to their ubiquitous presence in the environment and their detrimental effects on human health, there is a public interest in widespread testing for perfluoroalkyl substances (PFAS). However, the most common methods for PFAS analysis can be time-intensive, requiring a preconcentration step followed by liquid chromatography–mass spectrometry (LC–MS), and are cost-prohibitive for most members of the public. To address these challenges, this study explores a novel method for rapid analysis of aqueous analytes by concentrating analytes on solid adsorbents and detecting them using mass spectrometric analysis via desorption ionization directly from the adsorbent surface. We demonstrate this general approach of indirect solution analysis (ISA) with desorption electrospray ionization (ISA-DESI) and laser desorption ionization (ISA-LDI). Various adsorbent materials were screened, including commercial mesoporous carbons, alumina, and metal–organic frameworks (MOFs). Using ISA-DESI, we consistently detect concentrations as low as 5–100 parts per trillion (ppt) for perfluorooctanoic acid (PFOA) and 10–100 ppt for perfluoroundecanoic acid (PFUnDA). This approach enables rapid detection in under 5 min, making it suitable for applications requiring trace detection with fast response times. We further demonstrate the use of ISA-DESI on a range of environmentally relevant contaminants. Advantages of this indirect solution analysis approach include simplified sample preparation, accelerated analysis, and low cost with readily available materials, making it a promising tool to accelerate mass spectrometric PFAS detection for identifying contaminated sites, performing laboratory studies, and monitoring industrial waste streams.

Bays, Nathan Robert [Sandia National Laboratories ↗
DOE OSTI2023

Slow dynamics in a single bead with mechanical conditioning and transient heating

The contact stiffness of an aluminum bead confined between two slabs diminishes upon mechanical conditioning, and then recovers like log(t) after the conditioning ceases. Here that structure is evaluated for its response to transient heating and cooling, with and without accompanying conditioning vibrations. It is found that, under heating or cooling alone, stiffness changes are mostly consistent with temperature dependent material moduli; there is little or no slow dynamics. Hybrid tests in which vibration conditioning is followed by heating or cooling lead to recoveries that begin like log(t) and then become more complex. On subtracting the known response to heating or cooling alone we discern the influence of higher or lower temperatures on slow dynamic recovery from vibrations. It is found that heating accelerates the initial log(t) recovery, but by an amount more than predicted by an Arrhenius model of thermally activated barrier penetrations. Furthermore, transient cooling has no discernable effect, in contrast to the Arrhenius prediction that it slows recovery.

36 MATERIALS SCIENCE↗