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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 505 records · Page 28

HunStat2 – a simple and low-cost potentiostat with electrochemical impedance spectroscopy capability

We have developed a low-cost (30 USD), simple do-it-yourself (DIY) potentiostat with cyclic voltammetry (CV), open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) capability. The HunStat2 potentiostat is based on Analog Devices' AD5941 Analog Front End chip, which significantly simplifies the construction of potentiostats for both direct and alternating current (DC and AC, respectively) techniques. Interested readers are provided with circuit diagrams and a bill of materials to build the potentiostat on their own. In addition, control software is also provided free of charge. The software enables acquisition and visualization of data. In summary, HunStat2 introduces a simple and low-cost DIY potentiostat recommended for both analytical and educational purposes.

Vamos, Istvan [Lajos Petrik Vocational Chemistry S↗

Beyond optimization—supervised learning applications in relativistic laser-plasma experiments

We explore the applications of machine learning techniques in relativistic laser-plasma experiments beyond optimization purposes. We predict the beam charge of electrons produced in a laser wakefield accelerator given the laser wavefront change caused by a deformable mirror. Machine learning enables feature analysis beyond merely searching for an optimal beam charge, showing that specific aberrations in the laser wavefront are favored in generating higher beam charges. Supervised learning models allow characterizing the measured data quality as well as recognizing irreproducible data and potential outliers. Furthermore, we also include virtual measurement errors in the experimental data to examine the model robustness under these conditions. This work demonstrates how machine learning methods can benefit data analysis and physics interpretation in a highly nonlinear problem of relativistic laser-plasma interaction.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Improved modeling of in-ice particle showers for IceCube event reconstruction

The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstruction that better captures our current knowledge of ice optical properties. When evaluated on a Monte Carlo simulation set, the median angular resolution for in-ice particle showers improves by over a factor of three compared to a reconstruction based on a simplified model of the ice. The most substantial improvement is obtained when including effects of birefringence due to the polycrystalline structure of the ice. When evaluated on data classified as particle showers in the high-energy starting events sample, a significantly improved description of the events is observed.

47 OTHER INSTRUMENTATION↗

Paramagnetic electronic structure of CrSBr: Comparison between ab initio G W theory and angle-resolved photoemission spectroscopy

Here, we explore the electronic structure of paramagnetic CrSBr by comparative first-principles calculations and angle-resolved photoemission spectroscopy. We theoretically approximate the paramagnetic phase using a supercell hosting spin configurations with broken long-range order and applying quasiparticle self-consistent GW theory, without and with the inclusion of excitonic vertex corrections to the screened Coulomb interaction (QS GW and QS $G\widehat{W}$, respectively). Comparing the quasiparticle band-structure calculations to angle-resolved photoemission data collected at 200 K results in excellent agreement. This allows us to qualitatively explain the significant broadening of some bands as arising from the broken magnetic long-range order and/or electronic dispersion perpendicular to the quasi-two-dimensional layers of the crystal structure. The experimental band gap at 200 K is found to be at least 1.51 eV at 200 K. At lower temperature, no photoemission data can be collected as a result of charging effects, pointing towards a significantly larger gap, which is consistent with the calculated band gap of approximately 2.1 eV.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Energy dependence of polarized 𝛾⁢𝛾 → 𝑒 + ⁢ 𝑒− in peripheral Au+Au collisions at $\sqrt{s_{NN}}$ = 54.4 and 200 GeV with the STAR experiment at RHIC

We report the differential yields at mid-rapidity of the Breit-Wheeler process (𝛾⁢𝛾 → 𝑒 + ⁢𝑒 − ) in peripheral Au+Aucollisions at $\sqrt{s_{NN}}$ = 54.4 and 200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), as a function of energy $\sqrt{s_{NN}}$, 𝑒 + ⁢𝑒 − transverse momentum 𝑝 T , 𝑝$^{2}_{T}$, invariant mass 𝑀 𝑒⁢𝑒 , and azimuthal angle. In the invariant mass range of 0.4 < 𝑀 𝑒⁢𝑒 < 2.6GeV/𝑐 2 at low transverse momentum (𝑝 T < 0.15GeV/𝑐), the yields increase while the pair √⟨𝑝$^{2}_{T}$⟩ decreases with increasing $\sqrt{s_{NN}}$, a feature that is correctly predicted by the QED calculation. Here, the energy dependencies of the measured quantities are sensitive to the nuclear form factor, infrared divergence and photon polarization. The data are compiled and used to extract the charge radius of the Au nucleus.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Search for Nuclear Modifications of 𝐵 + Meson Production in 𝑝-Pb Collisions at $\sqrt{𝑠_{NN}}$ = 8.16 TeV

Nuclear medium effects on 𝐵 + meson production are studied using the binary-collision scaled cross section ratio between events of different charged-particle multiplicities from proton-lead collisions. Data, collected by the CMS experiment in 2016 at a nucleon-nucleon center-of-mass energy of $\sqrt{𝑠_{NN}}$ = 8.16 TeV, corresponding to an integrated luminosity of 175 nb −1 , were used. The scaling factors in the ratio are determined using a novel approach based on the 𝑍 → 𝜇 − ⁢𝜇 + cross sections measured in the same events. The scaled ratio for 𝐵 + is consistent with unity for all event multiplicities, putting stringent constraints on nuclear modification for heavy flavor.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Conditional diffusion machine-learning framework for mapping valence electron distribution from convergent beam electron diffraction

Quantitative convergent beam electron diffraction (CBED) enables determination of aspherical valence electron distributions through refinement of low-order structure factors, which are highly sensitive to chemical bonding and charge density variations. However, conventional quantitative CBED (QCBED) requires solving a highly nonlinear inverse problem with many coupled parameters, and computationally intensive dynamical diffraction calculations, making it time-consuming and difficult to apply to complex systems. More broadly, reconstructing charge density and orbital electron distribution from diffraction data has long been a central challenge in both x-ray and electron crystallography. Here, in this study, we introduce an artificial-intelligence (AI)-based framework that replaces traditional refinement with a data-driven inverse solver. Using a large synthetic CBED dataset generated by Bloch-wave simulations, we train a conditional diffusion model to directly infer crystal structural parameters and multipole density formalism parameters, and hence valence electron distributions, from CBED patterns alone. By learning from forward simulations across realistic parameter space, the model effectively solves the inverse problem. Compared with direct regression approaches, the diffusion-based framework provides posterior parameter distributions for rigorous uncertainty quantification while preserving quantitative fidelity and reducing analysis time by orders of magnitude. By eliminating the need for external single-crystal x-ray diffraction data and complex nonlinear refinement, this approach enables practical, high-throughput, and in situ quantitative CBED, enabling real-time mapping of valence electron distributions and their correlation with functional responses in quantum and energy materials.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

A Multiport DC Transformer to Enable Flexible Scalable DC as a Service

The rapid adoption of new DC loads and sources, including photovoltaic arrays, DC fast charging of electric vehicle, battery energy storage and data centers, requires a large amount of DC power conversion. A majority of new deployments also necessitate the integration of multiple DC loads and sources at one site. The traditional approach to serve these new applications relies on multiple standard power converters, each dedicated to a source or load, and results in highly customized systems, with challenging control coordination, complex protection strategies, and poor scalability. Instead, this paper proposes the concept of a multiport DC transformer (MDCT) as a modular building block for realizing a flexible, scalable DC as a Service system and address this rapidly growing need. The MDCT uses the S4T to achieve very tight control of cycle-by-cycle energy exchange between multiple ports, with high efficiency. A single multiport converter replaces 4-6 distinct converters, integrates all energy flows and manages protection. As a result, a new layered control architecture is introduced to ensure stability and scalability of the MDCT, with multiple S4T power converter building blocks connected in parallel to realize a fully modular system and reach the target power levels.

30 DIRECT ENERGY CONVERSION↗

Electrochemical Study of OH - in Molten MgCl 2 -NaCl-KCl Salts

Here the present study determines the equilibrium concentration of OH- in molten MgCl 2 -NaCl-KCl salts and measures the kinetic properties data of OH- (diffusion coefficient, exchange current density, charge transfer coefficient, limiting current density, and standard rate constant) accordingly at different temperatures. The equilibrium concentration of OH- descends as the temperature increases, which ranges from 4.11 to 2.84 × 10 -6 mol cm -3 in the temperature range of 600 °C–800 °C. The diffusion coefficient follows Arrhenius law with a value between 2.46 and 4.48 × 10 -4 cm 2 s -1 . The exchange and limit current densities, and standard rate constant increase with temperature. The calculated standard rate constant κ 0 follows Arrhenius law, which is in the range from 1.23 to 2.50 × 10 -4 cm s -1 . The measured charge transfer coefficient is independent of temperature, which validates the present measurements.

14 SOLAR ENERGY↗

GridPIQ Reference Data

GridPIQ uses dozens of publicly available datasets to provide context for a user's grid project, as well as defaults for users to choose from. Users can choose to import their own data to better customize their analysis or use GridPIQ-supplied defaults. This allows users to get up and running with an analysis very quickly without having to spend significant time pulling together input data. To run an electric vehicle (EV) smart charging project, a user will need to provide or select from prepopulated values for the regional load profile shape and peak load, region of interest and closest weather station, EV charging profile, number of EVs to add for the analysis, maximum EV charging power, location of chargers relative to grid infrastructure, and allowable charging times (for coordinated charging mode). The outputs of the analysis are changes in air quality, EV energy consumption, EV peak demand, and EV hourly consumption profile—before and after project implementation." For a detailed description of the tool methodology, including all the publicly available datasets used by the tool, see the [GridPIQ documentation](https://gridpiq.pnnl.gov/v2-beta/doc/).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

National Summary Statistics for Depot-Based Medium- and Heavy-Duty Vehicle Operations

This file provides nationally aggregated summary statistics to characterize the daily operations of medium- and heavy-duty vehicles. It provides typical daily driving distances, domicile dwell durations, and one version of potential normalized electric vehicle depot charging load curves. The methodology to create these data was designed with national representativeness in mind, and the data are suitable for national analysis.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Summary of changes to the ENDF library [Slides]

This presentation discusses the major revisions that the TSL sublibrary is undergoing. It also discusses mass(ive) sublibrary changes, charged particle evaluations, INDEN evaluations, and the non-INDEN neutron sublibrary. The presentation concludes by stating that there are conflicts that need to be resolved and that they have enough contributions that the executive committee feels that an ENDF/B-VIII.1 release is warranted by February 2023.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Evaluation of the mean excitation energy of liquid argon

Current and future experiments need to know the stopping power of liquid argon. It is used directly in calibration, where commonly the minimum-ionizing portion of muon tracks is used as a standard candle. Similarly, muon range is used as a measure of muon energy. More broadly, the stopping power figures into the simulation of all charged particles, and so uncertainty propagates widely throughout data analysis of all sorts. The main parameter that controls stopping power is the mean excitation energy, or I-value. Experimental information for argon's I-value come primarily from measurements of gaseous argon, with a very limited amount of information from solid argon, and none from liquid argon. These measurements are reviewed, along with a discussion of the difference in central value and uncertainty incurred by the difference of phase. The values newly recommended by this note are $(188 \pm 6)$ eV for gaseous argon and $(197 \pm 8)$ eV for liquid argon (68% C.L. in each case).

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Meas. K+ -Ar Total Inelastic Cross Section at ProtoDUNE-SP

ProtoDUNE-SP is a single-phase liquid argon time projection chamber that took hadron test beam data in 2018. The test beam included positively charged kaons with test beam momenta of 6 GeV/c and 7 GeV/c, providing a sample to study kaons to benefit future DUNE proton decay and neutrino interaction studies with kaons in the final state. The total inelastic cross section of a positively charged kaon was measured at these test beam settings using the LArIAT thin-slice method of dividing the wires of the time projection chamber into target slices for calculating the cross section, which leverages the monolithic quality of liquid argon detectors. A Bayesian-like unfolding method using RooUnfold was applied to both the incident and interacting slice distributions to measure the cross sections at both test beam momenta. The talk will discuss the method of unfolding, optimization studies for unfolding, and applying systematic uncertainties using a LArIAT-style hadronic cross section using unfolding to extract a kaon total inelastic cross section.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Measurement of Triple-Differential Inclusive Muon Neutrino Charged-Current Cross Sections on Argon with the MicroBooNE Detector

We report the first measurement of the differential cross section $d^2σ(E_ν)/dcos(θ_µ)dP_µ$for inclusive muon neutrino charged-current scattering on argon. This measurement utilizes data from6.5×10 20 protons on target of exposure collected using the MicroBooNE liquid argon time projection chamber located on-axis in the Fermilab Booster Neutrino Beam with a mean neutrino energy of approximately 0.8 GeV. In this note, the mapping from reconstructed kinematics to truth quantities, particularly from reconstructed to true neutrino energy, is validated by comparing the distribution of reconstructed hadronic energy in data to that of the model prediction in different muon scattering angle bins after conditional constraint from the muon momentum distribution in data. The success of this validation gives confidence that the missing energy in the MicroBooNE detector is well-modeled within its uncertainties in simulation, enabling the unfolding to an energy-dependent triple-differential measurement over muon momentum, muon scattering angle, and neutrino energy. The unfolded measurement covers an extensive phase space, providing a wealth of information useful for future LArTPC experiments measuring neutrino oscillations. Comparisons with model predictions show the best agreement with Neut 5.4.0.1 at low energy, and with NuWro 19.02.01 at higher energies, particularly at forward muon scattering angles.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Improving ProtoDUNE pion cross-section measurements with NuGraph Michel-electron tagging

Understanding hadron-argon interactions is essential for precise neutrino energy reconstruction and final-state interaction modeling in liquid-argon time projection chamber (LArTPC) experiments such as DUNE. In particular, pion absorption and charge-exchange processes constitute significant sources of systematic uncertainty in neutrino oscillation measurements. ProtoDUNE-SP, a large-scale LArTPC prototype operated at the CERN Neutrino Platform and exposed to charged-particle test beams in the few-GeV range, enables direct measurements of these processes. This work focuses on the measurement of differential cross sections for pion absorption and charge exchange using the 2 GeV/c pion beam data from the ProtoDUNE-SP run. A key component of this analysis is the identification of Michel electrons from $\pi \rightarrow \mu \rightarrow e$ decay chains, which helps separate different interaction topologies and improves background rejection. Michel electron identification will also assist in reliably calibrating the electromagnetic response in ProtoDUNE-SP data and for the future DUNE detectors. In this analysis, we apply NuGraph to identify Michel electrons. NuGraph is a graph neural network that models detector hits as nodes connected by spatial and temporal edges for particle and topology classification in LArTPC detectors. We first benchmark NuGraph’s Michel electron classification performance using ICEBERG data, a small-scale LArTPC prototype used for DUNE electronics and reconstruction development, and then transfer the approach to ProtoDUNE-SP. This poster presents the analysis strategy, NuGraph-based classification studies, and discusses how these developments are expected to improve the pion cross-section measurement.

Razafinime, Soamasina Herilala [Cincinnati U.] (OR↗

Determination and Comparison of Parameters from Cyclic Voltammetry of LaCl 3 in Eutectic LiCl-KCl

Electrochemical measurements of LaCl 3 were obtained in eutectic LiCl-KCl at 773 K. Cyclic voltammetry data were acquired using a tungsten electrode LaCl 3 amounts in the molten salt in the range of 0.5 to 3.0 wt%. Both cyclic voltammetry and Tafel analyses of the data resulted in calculation of values for the charge transfer coefficient (0.262), diffusion coefficient (1.67 × 10 -5 cm 2 s -1 ), exchange current density (0.0148 to 0.0473 A cm -2 ), and charge transfer resistance (0.404 to 1.99 Ω) related to lanthanum ions in the molten salt. Calculated values were compared to those available in the literature. The values of parameters found in literature varied significantly in comparison to those in the present study due to dissimilar experimental conditions, e.g., electrode material, temperature, and LaCl 3 concentration.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

How an Autonomous Offshore Power System Can Transform the Ocean Economy - A Hypothetical Case Study Utilizing an Autonomous Offshore Power System in Northern Lights Carbon Capture and Storage Project

An Autonomous Offshore Power System (AOPS) provides in-situ power, energy storage, real-time data and communications support, asset management, and other capabilities at sea. It has applications for all offshore industries: energy, defense and security, aquaculture, science and research, and communications. Furthermore, this paper highlights how an AOPS can reduce cost, complexity, and carbon-intensity for existing offshore operations and enable new capabilities for offshore industry leaders. This new AOPS technology has two primary advantages. First, it unlocks the autonomous, electric future of the ocean economy via ‘local’ power generation and energy storage, in addition to real-time connection to the data cloud. Second, it helps enable a material change in the global energy mix through cost-effective, reliable generation and storage technology for use cases including mobile/static data-gathering and reporting systems, operating equipment, and charging networks for uncrewed surface vessels. AOPS technology will help transform the ocean economy, and thus has implications for offshore industry leaders as they push to reduce costs today and make an autonomous and decarbonized future possible.

16 TIDAL AND WAVE POWER↗