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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Welding of the superfluid helium on-orbit transfer (SHOOT) Flight Demonstration tanks and hardware

The SHOOT Flight Demonstration will provide the technology necessary to resupply superfluid helium in space. The helium dewars in SHOOT have unique requirements, including no detectable leaks, demonstrated structural integrity to allow flight aboard the Space Shuttle, and low parasitic heat leak. The requirements, materials, and processes used to fabricate the two superfluid helium dewars, particularly as they apply to welding, are presented.

Mcclure, Sidney↗
NASA NTRS1989

Analysis of dewar and transfer line cooldown in Superfluid Helium On-Orbit Transfer Flight Experiment (SHOOT)

The Superfluid Helium On-Orbit Transfer Flight Experiment (SHOOT) is designed to demonstrate the techniques and components required for orbital superfluid (He II) replenishment of observatories and satellites. One of the tasks planned in the experiment is to cool a warm cryogen tank and a warm transfer line to liquid helium temperature. A math model, based on single-phase vapor flow heat transfer, has been developed to predict the cooldown time, component temperature histories, and helium consumption rate, for various initial conditions of the components and for the thermomechanical pump heater powers of 2 W and 0.5 W. This paper discusses the model and the analytical results, which can be used for planning the experiment operations and determining the pump heater power required for the cooldown operation.

Ng, Y. S.↗
NASA NTRS1991

Flow of superfluid helium in tubes with heated walls

The equations for superfluid helium flowing through a straight tube with heated walls are integrated. The model equations are based on those of Landau as modified for superfluid turbulence by Gorter and Mellink (1949). The model is implemented by the program SUPERFLOW which runs on a personal computer. The effect of the heating level on the mass flux, the energy flux, and the pressure and temperature profiles is investigated. The four types of profiles which occur without sidewall heating are also found with heated walls. The progression through these four types is shown to depend primarily on the dimensionless parameter, defined previously to characterize the unheated profiles, and a dimensionless ratio of heat fluxes. The pressure and temperature maxima which rise well above the boundary values increase significantly with sidewall heating. Approximate design equations for estimating the mass flux and the profiles are presented. The physical basis of the results is discussed. These results are useful in the design of optimal cooling loops and other superfluid flow systems.

Snyder, H. A.↗
NASA NTRS1984

Infrared Astronomical Satellite (IRAS) superfluid helium tank temperature control

The infrared detectors on the Infrared Astronomical Satellite (IRAS), which was placed into a polar orbit in January 1983, are cooled to a temperature of less than 3 K by thermal coupling to the main cryogenic tank (MCT) containing superfluid helium. A porous plug built into the vent line entrance acts as a superfluid helium liquid/vapor separator in zero gravity. A description of the IRAS MCT flight porous plug is presented, and tests of the plug in situ are discussed, taking into account submerged plug tests, a restart test, and a cold vapor flow test. Aspects of flow rate determination in the case of an unavailability of flight flow rate data are also considered.

Petrac, D.↗
DOE OSTI2024

Breakdown of sound in superfluid helium

As elementary particles carry energy and momentum in the Universe, quasiparticles are the elementary carriers of energy and momentum quanta in condensed matter. And, as elementary particles, under certain conditions quasiparticles can be unstable and decay, emitting pairs of less energetic ones. Pitaevskii [Sov. Phys. JETP 9, 830 (1959)] proposed that such processes exist in superfluid helium, a quantum fluid where the very concept of quasiparticles was borne by Landau and which presented the first notable success of that concept. Pitaevskii’s decays have important consequences, including the possible breakdown of a quasiparticle [M. B. Stone et al. , Nature (London) 440, 187 (2006)]. Here, we present neutron scattering experiments, which provide evidence that such decays explain the collapsing lifetime (strong damping) of higher-energy phonon-roton sound-wave quasiparticles in superfluid helium. Importantly, this damping develops when helium is pressurized towards crystallization, or warmed towards approaching the superfluid transition. Our results resolve a number of puzzles raised by previous experiments and reveal the ubiquity of quasiparticle decays and their importance for understanding quantum matter.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1980

Superfluid helium film in zero gravity

The behaviour of nearly-saturated superfluid helium films several hundred Angstroms thick was investigated under zero gravity conditions in a small cryostat carried on a 0.3 m diameter, 3 m long sounding rocket, using a quartz microbalance technique. The flight provided 30 s of high acceleration, about 5 min. of zero gravity, and 90 s of mg acceleration. The temperature of the experiment ranged from 1.67 to 2.15 K. In contrast to ground test results, thick films uniformly distributed on all surfaces were observed in zero gravity.

Yang, L. C.↗
NASA NTRS1981

Characterization of superfluid helium transfer

The friction factor and steady state flow rate of superfluid helium (He II) are measured, with the driving pressure difference generated by the saturated vapor pressure and a small hydrostatic pressure head. The temperature ranged from 1.5 K to the transition temperature of 2.17 K. Three different lengths and two different internal diameters were used for the stainless steel transfer tubes, and the transfer of liquid helium (He I) was investigated with the same apparatus for comparison. It was found that the friction factor of He II is greater than that of He I for pressure differences greater than 20 mm Hg, and smaller below that magnitude.

Yang, L. C.↗
NASA NTRS1989

Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm, and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (9 cycles at 4.2 K), and superfluid helium temperature (4 cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak-rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10(-9) std-cc/sec, during testing.

Salerno, Louis J.↗
NASA NTRS1991

Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (nine cycles at 4.2K) and superfluid helium temperature (four cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10 exp -9 std cu cm/s, during testing.

Salerno, L. J.↗
DOE OSTI2020

Quantum electronics and optics at the interface of solid neon and superfluid helium

Here, we predict a new quantum electronic structure at the interface between two condensed phases of noble-gas elements: solid neon and superfluid helium. An excess electron injected onto this interface self-confines its wavefunction into a nanometric dome structure. Its size varies with pressure and optical transitions cover a broad mid-infrared spectrum. A collection of such electrons can form a classical Wigner crystal resembling a quantum-dot array on a triangular lattice. Under ultrafast laser illumination, this Wigner crystal can exhibit the quantum optical phenomenon of superradiance in the picosecond time scale. The ultralong spin-coherence time and micron-scale deterministic configurability allow the electrons in this system to serve as quantum information carriers. Their spin states can be controlled and readout by on-chip single-electron devices.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1988

Superfluid Helium Tanker (SFHT) study

The accomplishments and recommendations of the two-phase Superfluid Helium Tanker (SFHT) study are presented. During the first phase of the study, the emphasis was on defining a comprehensive set of user requirements, establishing SFHT interface parameters and design requirements, and selecting a fluid subsystem design concept. During the second phase, an overall system design concept was constructed based on appropriate analyses and more detailed definition of requirements. Modifications needed to extend the baseline for use with cryogens other than SFHT have been determined, and technology development needs related to the recommended design have been assessed.

Source record↗
NASA NTRS1988

Superfluid Helium On-Orbit Transfer Flight Experiment - Performance estimates

Several components on the Superfluid Helium On-Orbit Transfer Flight Experiment are analyzed with respect to expected performance. The interaction of the components is then used to calculate an expected transfer efficiency. Steady state conditions are assumed. Transfer efficiencies based on the thermomechanical pump range from 96 to 99 percent plus. Transfer line parasitics lead to lower efficiencies at low flow rates.

Dipirro, M. J.↗
NASA NTRS1985

Design of the superfluid helium dewar for the Cosmic Background Explorer (COBE)

Design features of the 664-liter superfluid helium dewar to be used for the Cosmic Background Explorer (COBE) are described, with emphasis on the similarities and differences vis a vis the Infrared Astronomical Satellite (IRAS) dewar. The dewar (23 percent larger than the IRAS dewar) is intended to provide a 14-month operating lifetime (vs. 10 months for IRAS). A far infrared absolute spectrophotometer (FIRAS) and diffuse infrared background experiment (DIRBE) will conduct full sky surveys over the wavelength region from 1 micron to 1 centimeter. Launch into a 900-km sun-synchronous polar orbit is scheduled for the autumn of 1987.

Hopkins, R. A.↗
NASA NTRS1989

Design considerations for a micro-g superfluid helium fluid acquisition system

The general description, the operation, and the design of a superfluid helium (SFHe) fluid acquisition system (FAS) for use under microgravity conditions is presented. For the type of FAS considered here, where fine-mesh woven screens are used to retain flowing SFHe within a gallery arm (flow) channel, those forces which determine the flow dynamics are the micro-g accelerations, liquid surface tension, and tensile strength and cumulative pressure drops along a flow path that begins at the bulk liquid and ends at the entrance to a pump. For this case, the dimensionless number, N(T) is written as the ratio between the pressure drop across the screen and the surface tension forces at the screen for low fluid velocities. Static Bond number measurements have bene taken for SFHe using 325 x 2300 twilled Dutch screen and have indicated a screen pore hydraulic radius of 0.00031 cm.

Lee, J. M.↗
NASA NTRS1990

A design and critical technology issues for on-orbit resupply of superfluid helium

The issues of and the solutions to the critical design and technology areas of the Superfluid Helium On-Orbit Transfer (SHOOT) experiment, presently under development at the NASA Goddard Spaceflight Center, are discussed. Special attention is given to the SHOOT design requirements for the 10,000-liter superfluid He resupply tanker system, the concept details of the system, and the resupply operations and their analysis. A block diagram of the SHOOT system is included along with fluid management schematic and configuration diagrams of the system and its subsystems. A summary of the dewar performance is also presented.

Hopkins, Richard A.↗
NASA NTRS1988

Mechanical pumps for superfluid helium transfer in space

Two alternate mechanical pump concepts have been identified for the transfer of superfluid helium in space. Both pumps provide flow at sufficient head and have operating characteristics suitable for the Space Infrared Telescope Facility (SIRTF) refill mission. One pump operates at a relatively low speed and utilizes mechanical roller bearings, while the other operates at a higher rotational speed using either electromagnetic or tilting pad gas-dynamic bearings. The use of gas bearings requires transfer of normal helium so that the gas pressure within the pump casing is high enough to operate the bearings. The operating characteristics of both pumps are predicted, the dimensions are estimated and major technology issues are identified. The major issues for each pump design are cavitation performance and bearing development. Roller bearings require quantified reliability for operation in space while electromagnetic bearings require basic development as well as a complex control system. The low speed pump has significantly poorer hydraulic efficiency than the high speed pump.

Izenson, M. G.↗
NASA NTRS1983

A Report on Superfluid Helium Flow Through Porous Plugs for Space Science Applications

As a background for the study of the nature of superfluid helium flow through porous plugs for other space science uses, preliminary tests on various plugs of a given material, diameter, height, and filtration grade have been performed. Two characteristics of the plugs, pore size and number of channels, have been determined by the bubble test and warm flow test of helium gas through the plugs, respectively. Tests on the flow of He II through the plugs have also been performed. An obvious feature of the results of these tests is that for isothermal measurements of pressure versus mass flow rate below approximately 2.10 K, the flow is separated into two different regimes, indicative of the occurrence of a critical phenomenon.

Mason, F. C.↗
NASA NTRS1990

Computer based control of the Superfluid Helium On-Orbit Transfer Space Shuttle experiment

Ground software that is being developed for the control of the Superfluid Helium On-Orbit Transfer (SHOOT) project is discussed. Special attention is given to two software development projects for SHOOT support: (1) the SHOOT Command and Monitoring System, which will provide a real-time highly interactive interface for the SHOOT principal investigator to control the experiment and to analyze and display its telemetry; and (2) the SHOOT Aft Flight Deck Operating System, which is comprised of several monitoring programs to give the astronaut mission specialist on-orbit visibility into SHOOT systems, and an intelligent-rule-based system that will control a He transfer without ground intervention. Major accomplishments of the SHOOT project to date include two successful interface tests with the Goddard Space Flight Center developed breadboard electronics and prototype software.

Castellano, T. P.↗