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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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Morphological controls on flow conductivity and viscosity of bentonite–polymer composites

In this study, the authors investigate the morphological organisation of polymers in bentonite–polymer composites (BPCs) used in geosynthetic clay liners and controls on hydraulic conductivity and viscosity. A limited understanding of the relationship between the microstructure of BPCs and their macroscopic engineering behaviour motivates this study. The polymer resides in the inter-granular pores of bentonite based on synchrotron-based small-angle X-ray scattering measurements, scanning electron microscopy imaging and pore size analyses. On wetting, the polymer swells to produce a swollen hydrogel residing in the inter-granular pores. Enhanced tortuosity arising from hydrogel formation reduces the hydraulic conductivity of BPCs. The higher viscosity of the BPC slurry is attributed to the higher shear resistance emerging from swelling of the polymer fraction on wetting. These findings link the morphological features of BPCs to the observed hydraulic conductivity and viscosity of these materials.

Engineering↗
DOE OSTI2024

First conduction cooled photoinjector status

SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb3Sn and conduction cooling. SRF gun can provide a CW operation capability while consuming only 2W of RF power which eliminates the need of an expensive high power RF system and saves a facility footprint. Euclid is developing a continuous wave (CW), 1.5-cell, MeV-scale SRF conduction cooled photogun operating at 1.3 GHz. We aim for generation of the first beam in 2024. In this paper, we present the most up-to-date progress including results of the first cool down of the gun-cavity in the newly developed conduction cooled cryomodule and LLRF system development.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Thermal Conductivity of Electroplated Copper Onto Bulk Niobium at Cryogenic Temperatures

Superconducting radio-frequency (SRF) cavities made of high-purity bulk niobium are widely used in modern particle accelerators. The development of metallic outer coatings with high thermal conductivity would have a beneficial impact in terms of improved thermal stability, reduced material cost and for the development of conduction-cooled, cryogen-free SRF cavities. Several high-purity, fine-grain Nb samples have been coated with 2-4 mm thick copper by electroplating. Measurements of the thermal conductivity of the bimetallic Nb/Cu samples in the range 2 ? 7 K showed values of the order of 1 kW/(m K) at 4.3 K. Very good adhesion between copper and niobium was achieved by depositing a thin Cu layer by cold spray on the niobium, prior to electroplating the bulk Cu layer.

Dhakal, P.↗
DOE OSTI2026

Conduction-Cooled Operation of an SRF Multi-Cell Cavity

The development of compact, SRF-based accelerators for applications beyond research is experiencing notable advancements due to the use of cryocoolers for conduction-cooling instead of traditional liquid cryogens. Following the successful demonstration of a single-cell cavity operated through conduction cooling with three two-stage cryocoolers, Jefferson Lab (JLab) has made strides in the operation of a multi-cell resonator. This milestone paves the way for high-energy applications of compact, conduction-cooled SRF machines. The demonstration, carried out in collaboration with General Atomics, will take place in a dedicated horizontal test cryostat (HTC) at their San Diego facility. This presentation will highlight the technological developments, the latest results, and valuable lessons learned.

Vennekate, J. [Thomas Jefferson National Accelerat↗
DOE OSTI2023

Autonomous Fracture Conductivity Using Expandable Proppants in Enhanced Geothermal Systems

Summary Early thermal breakthrough in enhanced geothermal systems (EGS) due to the presence of preferential flow channels is a major challenge that endangers efficient and economic heat extraction in such systems. Previous studies mainly focused on adjusting circulation rates of the working fluid, which still leaves significant amounts of untapped heat behind. Currently, there is a lack of technologies for altering flow distribution within the fracture network to achieve uniform heat sweeping in the reservoir. This work presents a novel concept for making proppants to autonomously control fracture conductivity based on the surrounding temperature. Here, proppants with negative thermal expansion coefficients have demonstrated the capability for appropriate fracture conductivity adjustment as a function of temperature to achieve uniform flow across the fracture network. Particle-particle interactions governing such functions are explicitly modeled, and then the Lattice Boltzmann methods (LBM) is used to determine the potential impact of closure stress and temperature changes on the permeability of the proposed proppant packs. Microscale analyses are further used to determine the required material properties to achieve a certain improvement in the permeability of the proppant pack. Our analyses show an enhancement in permeability and the associated fracture conductivity by half of their initial values. Field-scale analysis further confirms the effectiveness of the proposed concept as 31.4% more heat can be extracted from EGS over 50 years of production when the proposed proppants are used. Such novel proppants may effectively delay thermal breakthrough, sweep heat from larger rock volumes, and elongate the life span of the EGS project.

Engineering↗
DOE OSTI2020

Characterization of vacuum conductance in commercially available (sintered) and additively manufactured porous structures

This report documents the work performed in characterizing the vacuum conductance of porous structures made by conventional sintering (purchased as commercially available products from Mott Corporation ranging from 20 to 100 media grade) and additive manufacturing (powder bed fusion). The additively manufactured structures described in this report were originally intended to be the first iteration of several in an effort to produce desirable conductance characteristics. While resources were not available to link the experimental results to a modeling effort to better understand why certain characteristics were observed, the author hopes that this report may provide a useful set of data for future use, especially as sintered porous structures are not uncommonly procured from Mott corporation for research and development purposes. For that reason, all of the raw data is tabulated in the Appendix: it is possible to reproduce all of the figures shown in this report independently. For a quick order-of magnitude scan of the conductances, refer to Figures 5, 6, 8 and 9.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Cryocooler conduction-cooled SRF cavities for compact particle accelerators

Cryocooler conduction cooling offers simple, reliable cryogenics for developing industrial SRF e-beam accelerators. Conduction-cooled SRF R&D at Fermilab: first demonstration >6.5 MV/m cw on a 650 MHz Nb 3 Sn coated cavity; prototype development and high power accelerators designs in progress. Cryocooler conduction cooling can greatly expand access to SRF: university groups, industries can embark on in house SRF R&D without needing full stack helium cryogenic systems

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Thermal Conductivity Measurement of Microstructure in Irradiated Materials

Argonne National Laboratory is establishing additional capabilities for advanced techniques for accelerated experiment-based fuel material screening. A key supporting element is expanded capabilities for the characterization of irradiated samples, including establishment of the capability to measure irradiated fuel thermal conductivity at the micro-scale level. Argonne is collaborating with the University of Illinois at Urbana-Champaign (UIUC) to adopt the suspended bridge method to measure thermal conductivity of radiation-induced microstructures in nuclear materials directly. The initial phase of work to support thermal conductivity measurements of microstructure in irradiated materials at Argonne has been executed, and is summarized here. This report is intended to serve as a status update for this activity, summarizing work completed in FY20.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Scaling-Up and Roll-to-Roll Processing if Highly Conductive Sulfide Solid-State Electrolytes (CRADA 510)

This project aims to identify and address key technical barriers in scale-up synthesis and roll-to-roll processing of highly conductive solid-state electrolytes (SSEs) by leveraging PNNL’s patent pending SSEs, Ampcera Inc.’s environmentally friendly manufacturing capability, and UW’s rollto-roll processing. The ultimate goals are 1) development of novel sulfide SSEs with room temperature Li+ conductivity > 5 mS/cm and Li/SSE interfacial resistance <5 Ωcm2, 2) scalable production of sulfide SSEs at 1 metric ton/year, and 3) a high throughput roll-to-roll processing of highly conductive (>1 mS/cm) and ultra-thin solid film (10-100 μm). The materials and the solid film achieved in the project will be tested at practical conditions and validated in a realistic pouch cell format with achievable energy > 300 Wh/Kg.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam during Water Year 2021

This report was prepared by Argonne National Laboratory (Argonne) in support of a financial analysis of two Glen Canyon Dam (GCD) flow experiments that were conducted in Water Year 2021. The first experiment, called “spring disturbance flow”, was conducted from March 15 to 26, 2021. This disturbance flow experiment is designed to simulate a spring-timed runoff event so scientists can study its effects on the Colorado River ecosystem. The second experiment was a reduced and steady discharge from May 29 to June 4, 2021. This reduced steady flow experiment was conducted for the United States Geological Survey (USGS) to collect high-resolution aerial imagery over Grand Canyon National Park. This analysis was funded by the Colorado River Storage Project (CRSP) Office of the U.S. Department of Energy’s Western Area Power Administration (WAPA). CRSP markets electricity produced by hydroelectric facilities collectively known as the Salt Lake City Area Integrated Projects including dams equipped for power generation on the Colorado, Green, Gunnison, and Rio Grande Rivers and on Plateau Creek in the states of Arizona, Colorado, New Mexico, Utah, and Wyoming. Staff members in Argonne’s Energy Systems Division prepared this technical memorandum with assistance from WAPA’s CRSP and Energy Marketing and Management Offices (EMMO).

58 GEOSCIENCES↗
DOE OSTI2021

Overview on Recent Development of Conduction Cooling Cavities

Improvements in both the cooling power of 4 K crycoolers and the deposition of Nb3Sn films have spurred research and development efforts towards the operation of Nb3Sn-coated SRF cavities cooled by conduction with commercial cryocoolers. Different types of SRF cavities with frequencies between 650 MHz and 2.6 GHz and different conduction cooling schemes have been tested at different laboratories, demonstrating accelerating gradients up to ~10 MV/m. This contribution provides an overview of these and future efforts along with possible cryostat designs under evaluation for conduction-cooled SRF cavities.

Ciovati, G.↗
DOE OSTI2021

Thermal Conductivity of Electroplated Copper Onto Bulk Niobium at Cryogenic Temperatures

Superconducting radio-frequency (SRF) cavities made of high-purity bulk niobium are widely used in modern particle accelerators. The development of metallic outer coatings with high thermal conductivity would have a beneficial impact in terms of improved thermal stability, reduced material cost and for the development of conduction-cooled, cryogen-free SRF cavities. Several high-purity, fine-grain Nb samples have been coated with 2-4 mm thick copper by electroplating. Measurements of the thermal conductivity of the bimetallic Nb/Cu samples in the range 2 ? 7 K showed values of the order of 1 kW/(m K) at 4.3 K. Very good adhesion between copper and niobium was achieved by depositing a thin Cu layer by cold spray on the niobium, prior to electroplating the bulk Cu layer.

Dhakal, P.↗
DOE OSTI2022

Synthesis and Photonic Sintering of Proton Conducting Lanthanide Nickelates

Lanthanide nickelate perovskites are known proton conductors at intermediate temperatures (350-600°C). They are attractive targets for proton conducting fuel cells and electrolyzers due to their operational temperature range and their stability in the presence of CO 2 . These materials have the formula LNiO 3 , with the lanthanide L = La, Ce, Pr, Nd, or Sm. Sintering is challenging due to phase transformations that occur at lower temperatures than those required for sintering. In this project, a series of lanthanide nickelate perovskites was synthesized via both a precursor solid solution method and the glycine nitrate process. Powders derived from the precursor solid solution method for LaNiO 3 and NdNiO 3 were sintered at Utility Global Inc. at various temperatures utilizing fast photonic sintering. LaNiO 3 was successfully sintered while maintaining the perovskite phase. NdNiO 3 underwent a phase transformation at all the conditions tested. The stability of the perovskite phase decreases moving right across the lanthanides in the periodic table, while the expected proton conductivity increases. These results will inform further investigations into lanthanide nickelate perovskites toward the goal of producing a free-standing, sintered, proton-conducting membrane.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Formulation of Conductive Inks for DIW Printed Battery Electrodes

Ink formulations for DIW printing of Li ion battery electrodes were optimized for high conductivity, surface area and printability. Our focus is particularly on optimizing Li-ion battery electrodes for low temperature applications by 3-D printing the cathodes into high surface area shapes. The sluggish kinetics of ion transport at the solid-electrolyte phase boundary can be a major problem in batteries at low temperatures, so optimizing for ion transport can help combat these issues. Two families of DIW ink were investigated; aqueous conductive polymer suspension with graphene nano platelets (GNP) ink, and “oil in water” graphene oxide (GO) micro emulsion ink which carbonizes to an open cell graphene aerogel. By iterative formulation changes, the conductivity of PEDOT:PSS based ink was increased over tenfold, and stiffness of GO emulsion ink was increased to provide better printability without sacrificing porosity.

36 MATERIALS SCIENCE↗
DOE OSTI2024

FY24 Progress Report on Viscosity and Thermal Conductivity Measurements of Nuclear Industry Relevant Chloride Salts: An Experimental and Computational Study

As presented in this report, experimental and computational techniques were performed to assess the viscosity and thermal conductivity of key alkali and actinide chloride mixtures for molten salt reactor developers. These mixtures were pure LiCl, NaCl-KCl, LiCl-NaCl, LiCl-KCl, LiCl-NaCl-KCl, and NaCl-UCl 3 . Experimental measurements of viscosity were performed with a rolling ball viscometer, whereas experimental measurements of thermal conductivity were performed with a variable gap apparatus. Additional benchmarking work was performed using both property measurement systems to prepare for x-ray radiography in stainless-steel crucibles for viscosity and to ensure that calibration methods were accurate for thermal conductivity before assessing the NaCl-UCl 3 system. Validation data for the NaCl-UCl 3 in literature are minimal. Details on the calibration methods, salt measurement processes, and sources of error and uncertainty are discussed in detail for both property measurements. The computational methods described herein involved ab-initio molecular dynamics (AIMD) calculations using CP2K. The calculations were performed for the LiCl-KCl-NaCl and NaCl-UCl 3 systems. These calculations not only provided thermophysical property estimations for comparison to experimental data, but they also allowed for the determination of diffusion coefficients, coordination numbers, and radial distribution functions to provide insight into ion mobility and local coordination environments, which is linked to macroscopic property trends.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2026

Porin-Inspired Ionomers with sub-nm Gated Ion Channels for High Ion Conductivity and Selectivity (Final Project Report (2026))

The physiological functions of living systems heavily rely on biological ion channels, whose malfunction can lead to disease. These channels enable selective and regulated transport of water, ions, or small molecules across membranes. Analogously, ionomers used in energy conversion and storage technologies govern ion transport within membrane separators and catalyst binder layers. This DOE Office of Science Early CAREER project aimed to achieve molecular-level control over ionic conductivity and ion permselectivity by translating the functionalities of biological, gated ion channels into a novel class of ion-conducting polymers (ionomers) incorporating macrocyclic calix[4]arene-based repeat units. The overarching goal was to establish fundamental design principles and elucidate proton conduction mechanisms through strategic design of macrocyclic calix[4]arene-containing ionomers, with close relevance to energy conversion and storage devices, including proton exchange membrane fuel cells (PEMFCs). The project leveraged sub-nm-sized macrocyclic pores to facilitate exceptionally fast ion transport (beneficial to addressing sluggish ORR kinetics of PEMFC electrodes) and achieve functionalities of ionic diodes under applied electrochemical fields, beneficial for selective transport/separation.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Comparison of copper and aluminum as the thermal link material for conduction-cooled accelerator cavities

Cryocooler conduction-cooling has recently emerged as a new frontier for cryogenic cooling for superconducting radiofrequency (SRF) cavities. In this scheme, an SRF cavity is mechanically coupled to a closed-cycle cryocooler using linkages made of high thermal conductivity metals. In this note, we compare the thermal transport properties of high purity aluminum and high purity copper as applied to SRF cavity conduction cooling. We show that copper can enable faster cooldown than aluminum from room temperature to the base temperature near 4 K and behave equally well or better during steady state cavity operation near the base temperature.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Conversion Kinetics and Ionic Conductivity in Na-β”-Alumina + YSZ (Naβ”AY) Sodium Solid Electrolyte via Vapor Phase Conversion Process

Sodium ion batteries have been receiving increasing attention and may see potential revival in the near future, particularly in large-scale grid energy storage coupling with wind and solar power generation, due to the abundant sodium resources, low cost, and sufficiently high energy density. Among the known sodium ion conductors, the Na-β”-alumina electrolyte remains highly attractive because of its high ionic conductivity. This study focuses on the vapor phase synthesis of a Na-β”-Alumina + YSZ (Naβ”AY) composite sodium electrolyte, which has higher mechanical strength and stability than conventional single phase β”-Alumina. The objectives are the measurement of conversion kinetics through a newly developed weight-gain based model and the determination of sodium ionic conductivity in the composite electrolyte. Starting samples contained ~70 vol% α-Alumina and ~30 vol% YSZ (3 mol% Y 2 O 3 stabilized Zirconia) with and without a thin alumina surface layer made by sintering in air at 1600 °C. The sintered samples were placed in a powder of Na-β”-alumina and heat-treated at 1250 °C for various periods. Sample dimensions and weight were measured as a function of heat treatment time. The conversion of α-Alumina in the α-Alumina + YSZ composite into Naβ”AY occurred by coupled diffusion of sodium ions through Na-β”-alumina and of oxygen ions through YSZ, effectively diffusing Na2O. From the analysis of the time dependence of sample mass and dimensions, the effective diffusion coefficient of Na 2 O through the sample, D eff , was estimated to be 1.74 x 10 -7 cm2 s -1 , and the effective interface transfer parameter, k eff , was estimated as 2.33 x 10 -6 cm s -1 . By depositing a thin alumina coating layer on top of the bulk composite, the chemical diffusion coefficient of oxygen through single phase Na-β”-alumina was estimated as 4.35 x 10 -10 cm 2 s -1 . An AC impedance measurement was performed on a fully converted Naβ”AY composite, and the conductivity of the composite electrolyte was 1.3 x 10 -1 S cm -1 at 300 °C and 1.6 x 10 -3 S cm -1 at 25 °C, indicating promising applications in solid state or molten salt batteries at low to intermediate temperatures.

36 MATERIALS SCIENCE↗