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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Passively Cooled Superconductors Final Report

A highly reflective spray-on coating and tile material has been under development at Kennedy Space Center (KSC) that scatters away most of the Sun’s energy, thereby allowing coated objects to remain cool in space. The best performing tile material has achieved 1% solar absorptivity while the best performing spray-on coating has achieved around 4%. Both versions passively maintain cryogenic temperatures below 120 K at 1 astronomical unit (AU) from the Sun, but the tile material consistently sustains temperatures below 90 K, which is low enough to preserve oxygen and methane in a liquid state. Besides keeping propellants cold, this “solar white” material has the potential to passively maintain high-temperature superconductors (HTS) in a superconducting state without the support of liquid nitrogen cooling. If superconductors can be operated without the added infrastructure of liquid nitrogen cooling, it may enable them to be used in space for applications like magnetic radiation shielding and efficient energy management. Long duration exposure to both galactic cosmic radiation and coronal mass ejections can pose health risks for the astronauts and increase the potential for damage to electronics. This makes shielding essential to accomplish long duration missions, particularly when astronauts are onboard. The objective of this project was to determine the extent we could keep a high-temperature superconducting (HTS) material passively chilled to maintain its superconducting state. Both the tile and spray-on versions of solar white were investigated. We focused on finding a version that could support passive cooling at 1 AU from the Sun and determined the closest operating distances for samples that were unable to perform at 1 AU. Early in the project, we selected bismuth strontium calcium copper oxide (BSCCO) as the HTS to test based on its reputable usage in superconducting wires. The version we selected was Bi-2223, which has a critical temperature of about 108 K. Sample bars with contacts for a four-point probe were obtained from Quantum Levitation: https://quantumlevitation.com/product/superconductor-bar-for-4-point-tc-experiment/.

superconductors↗
NASA NTRS1985

A cryogenically cooled, multidetector spectrometer for infrared astronomy

A liquid helium-cooled, 24 detector grating spectrometer was developed and used for low resolution astronomical observations in the 5 to 14 micron spectral range. The instrument operated on the 91 cm Kuiper Airborne Observatory, the 3 m IRTF (Mauna Kea), the 3 m Shane telescope (Lick Observatory), and the 152 cm NASA and University of Arizona telescope. The detectors are discrete Si:Bi photoconductors with individual metal oxide semiconductor field effect transistor preamplifiers operating at 4 K. The system uses a liquid helium-cooled slit, order-sorter filter, collimator mirror, grating, and camera mirror arranged in a Czerny-Turner configuration with a cold stop added between the collimator mirror and the grating. The distances between components are chosen so that the collimator mirror images the secondary mirror of the telescope onto the cold stop, thus providing a very effective baffle. Scattered radiation is effectively reduced by using liquid helium-cooled, black baffles to divide the spectrometer into three separate compartments. The system noise-equivalent flux density, when used on the 152 cm telescope from 8 to 13 microns with a resolving power of 50, is 4.4 x 10 to the minus 17th power W/sq cm micron square root of Hz. The main applications are for measuring continuum radiation levels and solid state emission and absorption features in regions of star and planet formation.

Witteborn, F. C.↗
NASA NTRS1984

A cryogenically cooled, multidetector spectrometer for infrared astronomy

A liquid helium-cooled, 24 detector grating spectrometer was developed and used for low resolution astronomical observations in the 5 to 14 micron spectral range. The instrument operated on the 91 cm Kuiper Airborne Observatory, the 3 m IRTF (Mauna Kea), the 3 m Shane telescope Observatory, the 3 m Shane telescope (Lick Observatory), and the 152 cm NASA and University of Arizona telescope. The detectors are discrete Si:Bi photoconductors with individual metal oxide semiconductor field effect transistor preamplifiers operating at 4 K. The system uses a liquid helium-cooled slit, order-sorter filter, collimator mirror, grating, and camera mirror arranged in a Czerny-Turner configuration with a cold stop added between the collimator mirror and the grating. The distances between components are chosen so that the collimator mirror images the secondary mirror of the telescope onto the cold stop, thus providing a very effective baffle. Scattered radiation is effectively reduced by using liquid helium-cooled, black baffles to divide the spectrometer into three separate compartments. The system noise-equivalent flux density, when used on the 152 cm telescope from 8 to 13 microns with a resolving power of 50, is 4.4 x 10 to the minus 17th power W/sq cm micron square root of Hz. The main applications are for measuring continuum radiation levels and solid state emission and absorption features in regions of star and planet formation.

Witteborn, F. C.↗
NASA NTRS1991

A liquid/gas phase separator for He-I and He-II

A liquid/gas phase separator has been developed which separates both liquid He-I and He-II from their vapor. The phase separator was designed for the Superfluid Helium On Orbit Transfer (SHOOT) Flight Demonstration both to cool the liquid He after launch (at temperatures between 2.8 and 4.3 K) to the operating temperature of 1.4 K and as a low rate vent on orbit to maintain operating temperature. The phase separator is made of high-purity copper disks held apart by 6 micron Kevlar fibers. It works on the principle of conducting heat from within the dewar to vaporize liquid as it is throttled in the slits to efficiently cool the remaining liquid. Laboratory tests have demonstrated perfect phase separation for both He at its saturated vapor pressure from 1.2 to 4.3 K and for He-II at 2.13 K at pressures from 4.6 to 112 kPa. The performance of this phase separator during lab testing as well as expected performance in space is discussed.

Shirron, P. J.↗
DOE OSTI2021

SAS4A/SASSYS-1 Lead Verification Test Suite

SAS4A/SASSYS-1 is a simulation tool used to perform deterministic analyses of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal-cooled nuclear reactors. With its origin as SAS1A in the late 1960s, the SAS series of codes has been under continuous use and development for over forty-five years and represents a critical investment in safety analysis capabilities for the U.S. Department of Energy. Although SAS4A/SASSYS-1 was developed to support the analysis of any liquid-metal-cooled nuclear reactor, it has primarily been utilized to design and analyze Sodium Fast Reactors (SFRs). As a result, most of the verification basis for SAS4A/SASSYS-1 utilizes sodium as a coolant and geometry descriptions that are typical of a SFR facility. In this work, new verification problems are defined to extend the applicability of the SAS4A/SASSYS-1 verification basis into Lead Fast Reactor (LFR) design space. A review of the existing SAS4A/SASSYS-1 SFR verification test suite is performed to determine the number of test cases that are SFR specific. SFR specific test cases are replicated using lead as a coolant and system layouts that are representative of LFRs. This report provides definitions and reference solutions for seven new test cases that scope lead-specific features and capabilities of the software. For a verification test to be considered acceptable, comparisons of analytical solutions to SAS4A/SASSYS-1 predictions must produce negligible or justifiable errors. All LFR specific test cases are found to be acceptable.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Qualification of System-Level Advanced Reactor Safety Analysis Software for Lead Systems: Final CRADA Report

SAS4A/SASSYS-1 is a simulation tool used to perform deterministic analysis of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal-cooled nuclear reactors. With its origin as SAS1A in the late 1960s, the SAS series of codes has been under continuous use and development for over forty-five years and represents a critical investment in safety analysis capabilities for the U.S. Department of Energy. Although SAS4A/SASSYS-1 was developed to support the analysis of any liquid-metal-cooled nuclear reactor, it has primarily been utilized to design and analyze Sodium Fast Reactors (SFRs). As a result, most of the qualification basis for SAS4A/SASSYS-1 has utilized sodium as a coolant and geometry descriptions that are prototypic of SFR configurations. In this project, which partnered with Westinghouse Electric Company, LLC, the initial foundation for a qualification basis centered on prototypic pool-type lead-cooled systems has been established, where the end goal is to extend support for utilization of SAS4A/SASSYS-1 in Lead Fast Reactor (LFR) licensing or authorization. This project included three fundamental technical tasks: LFR V&V test suite development (Task 1); qualification support for LFRs (Task 2); and LFR modeling capabilities evaluation and improvement (Task 3)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1993

Heat pipe cooled heat rejection subsystem modelling for nuclear electric propulsion

NASA LeRC is currently developing a FORTRAN based computer model of a complete nuclear electric propulsion (NEP) vehicle that can be used for piloted and cargo missions to the Moon or Mars. Proposed designs feature either a Brayton or a K-Rankine power conversion cycle to drive a turbine coupled with rotary alternators. Both ion and magnetoplasmodynamic (MPD) thrusters will be considered in the model. In support of the NEP model, Rocketdyne is developing power conversion, heat rejection, and power management and distribution (PMAD) subroutines. The subroutines will be incorporated into the NEP vehicle model which will be written by NASA LeRC. The purpose is to document the heat pipe cooled heat rejection subsystem model and its supporting subroutines. The heat pipe cooled heat rejection subsystem model is designed to provide estimate of the mass and performance of the equipment used to reject heat from Brayton and Rankine cycle power conversion systems. The subroutine models the ductwork and heat pipe cooled manifold for a gas cooled Brayton; the heat sink heat exchanger, liquid loop piping, expansion compensator, pump and manifold for a liquid loop cooled Brayton; and a shear flow condenser for a K-Rankine system. In each case, the final heat rejection is made by way of a heat pipe radiator. The radiator is sized to reject the amount of heat necessary.

Moriarty, Michael P.↗
NASA NTRS1985

Evolution of systems concepts for a 100 kWe class Space Nuclear Power System

Conceptual designs for the SP-100 Space Nuclear Power System have been prepared that meet baseline, backup and growth program scenarios. Near-term advancement in technology was considered in the design of the Baseline Concept. An improved silicon-germanium thermoelectric technique is used to convert the heat from a fast-spectrum, liquid lithium cooled reactor. This system produces a net power of 100 kWe with a 10-year end of life, under the specific constraints of area and volume. Output of the Backup Concept is estimated to be 60 kWe for a 10-year end of life. This system differs from the Baseline Concept because currently available thermoelectric conversion is used from energy supplied by a liquid sodium cooled reactor. The Growth Concept uses Stirling engine conversion to produce 100 kWe within the constraints of mass and volume. The Growth Concept can be scaled up to produce a 1 MWe output that uses the same type reactor developed for the Baseline Concept. Assessments made for each of the program scenarios indicate the key development efforts needed to initiate detailed design and hardware program phases. Development plans were prepared for each scenario that detail the work elements and show the program activities leading to a state of flight readiness.

Katucki, R.↗
DOE OSTI2024

SAS4A/SASSYS-1 Verification Testing for Sodium Fast Reactor Applications (Acceptance Testing Report)

SAS4A/SASSYS-1 (SAS) is a simulation tool used to perform deterministic analyses of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal- cooled nuclear reactors. With its origin as SAS1A in the late 1960s, the SAS series of codes has been under continuous use and development for over fifty years and represents a critical investment in safety analysis capabilities for the U.S. Department of Energy. To support demonstration of software pedigree and confirm key functional requirements, this report has been generated to provide detailed verification of the software. Although SAS was developed to support the analysis of any liquid-metal-cooled nuclear reactor, the acceptance testing described in this document focuses on the verification of SAS capabilities as they relate to pool-type Sodium Fast Reactors (SFRs). This report includes documentation of the test problem definition, analytical solution(s), computational solution(s), acceptance criteria, comparisons of analytical/computational solutions, and determination of acceptance of the computational solution(s). Deviations from acceptance criteria are noted.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

SAS4A/SASSYS-1 Verification Testing for Sodium Fast Reactor Applications: Acceptance Testing Report

SAS4A/SASSYS-1 (SAS) is a simulation tool used to perform deterministic analyses of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal-cooled nuclear reactors. With its origin as SAS1A in the late 1960s, the SAS series of codes has been under continuous use and development for over forty-five years and represents a critical investment in safety analysis capabilities for the U.S. Department of Energy. To support demonstration of software pedigree and confirm key functional requirements, this report has been generated to provide detailed verification of the software. Although SAS was developed to support the analysis of any liquid-metal-cooled nuclear reactor, the acceptance testing described in this document focuses on the verification of SAS capabilities as they relate to pool-type Sodium Fast Reactors (SFRs). This report includes documentation of the test problem definition, analytical solution(s), computational solution(s), acceptance criteria, comparisons of analytical/computational solutions, and determination of acceptance of the computational solution(s). Deviations from acceptance criteria are noted.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2025

SAS4A/SASSYS-1 Verification Testing for Sodium Fast Reactor Application: Acceptance Testing Report

AS4A/SASSYS-1 (SAS) is a simulation tool used to perform deterministic analyses of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal-cooled nuclear reactors. With its origin as SAS1A in the late 1960s, the SAS series of codes has been under continuous use and development for over sixty years and represents a critical investment in safety analysis capabilities for the U.S. Department of Energy. To support the dedication effort, this report has been generated to provide a detailed description of the available verification testing. The verification testing presented in this report captures functionality testing, focusing mainly on the testing of specific functions and algorithms for accuracy and precision of output, and interface testing, focusing mainly on the testing of critical input parameters and their valid ranges. Although SAS was developed to support the analysis of any liquid-metal-cooled nuclear reactor, the testing described in this document primarily focuses on the verification of SAS capabilities as they relate to a generic pool-type Sodium Fast Reactor (SFR).

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1972

Liquid pump for astronaut cooling

The Apollo portable life support system water-recirculation pump used for astronaut cooling is described. The problems associated with an early centrifugal pump and how these problems were overcome by the use of a new diaphragm pump are discussed. Performance comparisons of the two pump designs are given. Developmental problems and flight results with the diaphragm pump are discussed.

Carson, M. A.↗
NASA NTRS1991

Design and performance of a high-Tc superconductor coplanar waveguide filter

The design of a coplanar waveguide low-pass filter made of YBa2Cu3O(7-delta) (YBCO) on an LaAlO3 substrate is described. Measurements were incorporated into simple models for microwave CAD analysis to develop a final design. The patterned and packaged coplanar waveguide low-pass filter of YBCO, with dimensions suited for integrated circuits, exhibited measured insertion losses when cooled in liquid nitrogen superior to those of a similarly cooled thin-film copper filter throughout the 0 to 9.5 GHz passband. Coplanar waveguide models for use with thin-film normal metal (with thickness either greater or less than the skin depth) and YBCO are discussed and used to compare the losses of the measured YBCO and copper circuits.

Chew, Wilbert↗
DOE OSTI2025

Minimization of thermal deformation in crystal optics for high repetition-rate FEL

Minimizing thermal deformation in X-ray crystal optics is crucial for preserving coherence and wavefront in high-repetition-rate free-electron lasers (FELs). This study presents two approaches to reduce pulse-by-pulse transient thermal deformation in diamond crystals used in cavity-based X-ray FELs (CBXFELs): (1) cryogenic cooling with liquid nitrogen (LN₂), and (2) second-order correction via focusing optics. We revisit the temperature-dependent thermal-mechanical properties of diamond and silicon, implement a finite-element analysis (FEA) method to accelerate convergence to a quasisteady-state regime. Results show that LN₂-cooled diamond crystals meet the stringent deformation requirement of less than 15 pm RMS for the pulse at mJ scale at 1 MHz repetition frequency, and up to 1.5 mJ for 100 kHz. Second-order correction by using focusing elements within the cavity can reduce the impact of thermal deformation for both liquid nitrogen and water cooling.

free electron laser↗
NASA NTRS1974

A cooled telescope for infrared balloon astronomy

The characteristics of a 16 inch liquid helium cooled Cassegrain telescope with vibrating secondary mirror are discussed. The telescope is used in making far infrared astronomical observations. The system houses several different detectors for multicolor photometry. The cooled telescope has a ten to one increase in signal-to-noise ratio over a similar warm version and is installed in a high altitude balloon gondola to obtain data on the H2 region of the galaxy.

Frederick, C.↗
DOE OSTI2025

Status of Multiple Channel Fuel Performance Capabilities Within the SAS4A/SASSYS-1 Safety Analysis Software

SAS4A/SASSYS-1 (SAS) is a fast-running simulation tool used to perform deterministic analysis of anticipated events as well as design basis and beyond design basis accidents for advanced liquid-metal-cooled nuclear reactors. It is a critical element of safety analysis capabilities for the U.S. Department of Energy and is utilized within industry to perform the transient safety analyses required to support the licensing of Liquid Metal-cooled Fast Reactors (LMFRs). Although SAS is exceptionally fast for most transient scenarios, fuel performance calculations, along with the associated pre-transient characterization of the fuel pin, may be required for transient scenarios where fuel pin failure is hypothesized. Both the pre-transient characterization and the transient fuel performance calculation are necessary to properly quantify margins to potential fuel failure and assess the time spent potentially exceeding such margins during events. While safety analysis calculations with fuel performance models provide a more detailed characterization of the reactor during a transient, the pre-transient characterization can be time-consuming and computationally expensive. Often, large numbers of fuel pins have been exposed to similar pre-transient irradiation conditions. Similarly, the same pre-transient fuel characterization may be applicable to numerous transient conditions. This provides an opportunity to optimize the SAS computational framework such that pre-transient fuel characterization can be shared across multiple channels (fuel pins) and across multiple simulations, thus dramatically reducing overall computational costs. This report summarizes progress toward enhancing the SAS computational framework to support shared, multiple channel fuel performance characterizations intended to significantly reduce computational costs. Preliminary testing has shown that the computational time saved by using the pre-transient sharing capability is approximately equal to the time it takes to perform the pre-transient characterization.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2020

Conceptual Design of a Conduction-Cooled Superconducting Undulator

In superconducting undulators (SCUs) that are currently operating at the Advanced Photon Source, the undulator magnets are indirectly cooled with liquid helium penetrating through channels in the magnet cores. The liquid helium is stored in a tank that is cooled by cryocoolers. However, a cryogen-free version of a superconducting undulator in which the undulator magnets are conduction-cooled is also possible, as has been realized in the SCUs developed at ANKA. We are currently working on a conceptual design of a conduction-cooled planar superconducting undulator. The measured load lines of cryocoolers and the measured thermal conductance of various thermal links are used in the thermal analysis. Also, various materials for the undulator magnet cores are being considered. This paper reports the thermal design of a conduction-cooled planar SCU.

cryocooler↗