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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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NASA NTRS1984

New model of Saturn's ionosphere with an influx of water from the rings

A radically different model of Saturn's ionosphere is proposed in which water plays a major role as a minor constituent present by downward diffusion from an external source. The model ionosphere is a classical F2 type layer resulting from the photodissociative production of H(+) from H2 and rapid chemical loss by a series of charge exchange reactions with water. A planet-wide influx of about 4 x 10 to the 7th molecules/sq cm/s of water from the rings is consistent with the observed ionospheric electron densities. An enhanced influx of water occurs at latitudes (-38, +44 deg) connected magnetically at the inner edge of Saturn's B ring, where an electromagnetic erosion process takes place. The present-day influx at these latitudes may be as large as 2 x 10 to the 9th molecules/sq cm/s.

Connerney, J. E. P.↗

NASA NTRS1985

Modification of the Electromagnetic Levitator (EML) Hardware

The goals of this project are: (1) to study the upgrade requirements and approaches needed for incorporation of an Electromagnetic Levitator (EML) into the shuttle orbiter, (2) to work with members of the Electromagnetic Containerless Processing science working group (SWG) to define future experiments for the EML, and (3) to assist these investigators in further development of ground-based experiment techniques to the limits possible in the terrestrial gravitational environment. Present work is directed toward: (1) upgrading the EML flight apparatus to meet requirements of safety and integration interfaces with the MSL orbiter carrier, (2) development of new experiment components required to carry out approved experiments in undercooled solidification and associated fluid flow studies directed by MIT, and (3) construction, test, qualification and integration assistance for the EML MSL flight package.

Frost, R. T.↗

NASA NTRS1986

Saturn: A unique magnetosphere/ionosphere/ring interaction

Latitudinal variations in images of Saturn's disk, upper atmospheric temperatures, and ionospheric electron density anomalies found in magnetic conjugacy with features in Saturn's ring plane are discussed. It is suggested that latitudinal variations are the result of a variable influx of water, transported along magnetic field lines from sources in Saturn's ring plane. Two such sources with optical counterparts in the inner B ring can be readily attributed to an electromagnetic erosion process that transports water in the form of high charge to mass ratio particles (ions or submicron grains with 1 electron charge) along magnetic field lines from the ring plane to Saturn's atmosphere. Another is attributed to erosion of the icy satellite Enceladus and the associated E ring.

Converney, J. E. P.↗

NASA NTRS1986

Saturn - A unique magnetosphere/ionosphere/ring interaction

Latitudinal variations in images of Saturn's disc, upper atmospheric temperatures, and ionospheric electron density anomalies are found in magnetic conjugacy with - i.e., magnetically linked to - features in Saturn's ring plane. It is suggested that these latitudinal variations are the result of a variable influx of water, transported along magnetic field lines from sources in Saturn's ring plane. Two such sources with optical counterparts in the inner B ring can be readily attributed to an electromagnetic erosion process that transports water in the form of high charge to mass ratio particles (ions or submicron grains with 1 electron charge) along magnetic field lines from the ring plane to Saturn's atmosphere. Another is attributed to erosion of the icy satellite Enceladus and the associated E ring.

Connerney, J. E. P.↗

NASA NTRS1989

Calculation of two-neutron multiplicity in photonuclear reactions

The most important particle emission processes for electromagnetic excitations in nucleus-nucleus collisions are the ejection of single neutrons and protons and also pairs of neutrons and protons. Methods are presented for calculating two-neutron emission cross sections in photonuclear reactions. The results are in a form suitable for application to nucleus-nucleus reactions.

Norbury, John W.↗

NASA NTRS1990

Calculation of two-neutron multiplicity in photonuclear reactions

Norbury, John W.↗

NASA NTRS1992

Observation of alloy solidification using high-speed video

A high-speed video instrumentation system was used to observe solidification of undercooled Ti-51 at. pct Al. The camera system developed by Battelle is capable of operation at rates up to 12,000 frames per second. The system digitizes and stores video images acquired by a 64 x 64 pixel silicon photodiode array. In a joint effort with Vanderbilt University the camera was used to observe three transformations of the undercooled alloys, using containerless processing by electromagnetic levitation. The first was solidification where nucleation was induced at an undercooling of 9 percent Tl, where Tl is the liquidus temperature of the alloy, and the second was solidification where nucleation was spontaneous at an undercooling of 15 percent Tl. The third event was a solid-state nucleation and growth transformation following the solidification at an undercooling of 15 percent Tl.

Bassler, B. T.↗

NASA NTRS2001

The Role of Convection and Growth Competition in Phase Selection in Microgravity: Controlled Convection in the Containerless Processing of Steel Alloys

Containerless processing using electromagnetic levitation (EML) is a powerful technique in the investigation of reactive molten metal systems. On ground, the power required to overcome the weight of the sample is sufficient to cause significant heating and induce substantial melt convection. In microgravity, the heating and positioning fields may be decoupled and the field strength may be varied to achieve the desired level of convection within the limits set by the geometry of the levitation coil and the sample size. From high-speed digital images of the double recalescence behavior of Fe-Cr-Ni alloys in ground-based testing and in reduced-gravity aboard the NASA KC-135 parabolic aircraft, we have shown that phase selection can be predicted based on a growth competition model. An important parameter in this model is the delay time between primary nucleation and subsequent nucleation of the stable solid within the liquid/metastable solid array. This delay time is a strong function of composition and a weak function of the undercooling of the melt below the metastable liquidus. From the results obtained during the first Microgravity Sciences Laboratory (MSL-1) mission, we also know that convection may significantly influence the delay time, especially at low undercoolings. Currently, it is unclear what mechanism controls the formation of a heterogeneous site that allows nucleation of the austenitic phase on the pre-existing ferrite skeleton. By examining the behavior of the delay time under different convective conditions, we hypothesize that we can differentiate between several of these mechanisms to gain an understanding of how to control microstructural. evolution. We will anchor these predictions by examining samples quenched at different times following primary recalescence in microgravity. A second important parameter in the growth competition model is the identification of the growth rate of the stable phase into the semi-solid array that formed during primary recalescence. Current dendritic growth theory is inadequate in predicting solidification behavior under these conditions as metallographic analyses show that stable phase growth proceeds along the interface between the metastable solid and residual liquid. Since growth velocity is independent of the initial undercooling relative to the metastable liquidus, we hypothesize that purely thermal effects can be separated from other important growth model parameters by careful selection of the liquid composition in a ternary system.

Matson, D. M.↗

NASA NTRS2001

Interpretation of InSAR mapping for geometrical structures

In this paper they present a methodology to detect large geometrical structures from Interferometric Synthetic Aperture Radar (InSAR) measurements.

InSAR processing electromagnetic scattering radar ↗

NASA NTRS2008

Millimeter-Wave Wireless Power Transfer Technology for Space Applications

In this paper we present a new compact, scalable, and low cost technology for efficient receiving of power using RF waves at 94 GHz. This technology employs a highly innovative array of slot antennas that is integrated on substrate composed of gold (Au), silicon (Si), and silicon dioxide (SiO2) layers. The length of the slots and spacing between them are optimized for a highly efficient beam through a 3-D electromagnetic simulation process. Antenna simulation results shows a good beam profile with very low side lobe levels and better than 93% antenna efficiency.

Slot Antenna↗

DOE OSTI2025

Searching for superheavy decaying particles with ultra-high-energy neutrino observatories

If there exist unstable but long-lived relics of the early universe, their decays could produce detectable fluxes of gamma rays and neutrinos. In this paper, we point out that the decays of superheavy particles, m χ ≳ 10 10 GeV, would produce an enhanced flux of ultra-high-energy neutrinos through the processes of muon and pion pair production in the resulting electromagnetic cascades. These processes transfer energy from electromagnetic decay products into neutrinos, relaxing the constraints that can be derived from gamma-ray observations, and increasing the sensitivity of high-energy neutrino telescopes to superheavy particle decays. Taking this into account, we derive new constraints on long-lived superheavy relics from the IceCube Neutrino Observatory, and from the Fermi Gamma-Ray Space Telescope. We find that IceCube-Gen2, and other next generation neutrino telescopes, will provide unprecedented sensitivity to the decays of superheavy dark matter particles and other long-lived relics.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

NASA NTRS1977

Research instrumentation for tornado electromagnetics emissions detection

Instrumentation for receiving, processing, and recording HF/VHF electromagnetic emissions from severe weather activity is described. Both airborne and ground-based instrumentation units are described on system and subsystem levels. Design considerations, design decisions, and the rationale behind the decisions are given. Performance characteristics are summarized and recommendations for improvements are given. The objectives, procedures, and test results of the following are presented: (1) airborne flight test in the Midwest U.S.A. (Spring 1975) and at the Kennedy Space Center, Florida (Summer 1975); (2) ground-based data collected in North Georgia (Summer/Fall 1975); and (3) airborne flight test in the Midwest (late Spring 1976) and at the Kennedy Space Center, Florida (Summer 1976). The Midwest tests concentrated on severe weather with tornadic activity; the Florida and Georgia tests monitored air mass convective thunderstorm characteristics. Supporting ground truth data from weather radars and sferics DF nets are described.

Jenkins, H. H.↗

NASA NTRS2012

Studies of Thermophysical Properties of Metals and Semiconductors by Containerless Processing Under Microgravity

Electromagnetic levitation under microgravity provides unique opportunities for the investigation of liquid metals, alloys and semiconductors, both above and below their melting temperatures, with minimized disturbances of the sample under investigation. The opportunity to perform such experiments will soon be available on the ISS with the EML payload which is currently being integrated. With its high-performance diagnostics systems EML allows to measure various physical properties such as heat capacity, enthalpy of fusion, viscosity, surface tension, thermal expansion coefficient, and electrical conductivity. In studies of nucleation and solidification phenomena the nucleation kinetics, phase selection, and solidification velocity can be determined. Advanced measurement capabilities currently being studied include the measurement and control of the residual oxygen content of the process atmosphere and a complementary inductive technique to measure thermophysical properties.

Seidel, A.↗

NASA NTRS1975

Study on processing immiscible materials in zero gravity

An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.

Reger, J. L.↗

DOE OSTI2023

Current rectification based on noncentrosymmetric quantum materials

Rectification is a process that converts electromagnetic fields into direct current (DC). Such a process underlies a wide range of technologies, including wireless communication, wireless charging, energy harvesting, and infrared detection. Existing rectifiers are mostly based on semiconductor diodes, with limited applicability to small voltages or high frequency inputs. Here, we present an alternative approach to current rectification that uses the electronic properties of quantum crystals without semiconductor junctions. We identify a new mechanism for rectification from skew scattering due to the chirality of itinerant electrons in time-reversal-invariant but inversion-breaking materials. Our calculations reveal large, tunable rectification effects in graphene multilayers and transition metal dichalcogenides. These effects can be used in high-frequency rectifiers by rational material design and quantum wavefunction engineering.

Isobe, Hiroki↗

NASA NTRS1985

Hybrid Contactless Heating and Levitation

Acoustic and electromagnetic fields applied. In contactless processing apparatus, acoustic and electromagnetic levitating fields employed alternately or simultaneously with amplitude of each controlled to produce various combinations of heating, cooling, and levitation. Apparatus provides rapid heating and cooling or slow heating and cooling for such processes as nucleation, crystallization, incubation, deep undercooling, and heterogeneity control.

Lee, M. C.↗

DOE OSTI2024

Celeritas: Accelerating Geant4 with GPUs

Celeritas [1] is a new Monte Carlo (MC) detector simulation code designed for computationally intensive applications (specifically, High Lumi- nosity Large Hadron Collider (HL-LHC) simulation) on high-performance heterogeneous architectures. In the past two years Celeritas has advanced from prototyping a GPU-based single physics model in infinite medium to implementing a full set of electromagnetic (EM) physics processes in complex geometries. The current release of Celeritas, version 0.3, has incorporated full device-based navigation, an event loop in the presence of magnetic fields, and detector hit scoring. New functionality incorporates a scheduler to offload electromagnetic physics to the GPU within a Geant4-driven simulation, enabling integration of Celeritas into high energy physics (HEP) experimental frameworks such as CMSSW. On the Summit supercomputer, Celeritas performs EM physics between 6 and 32 faster using the machine’s Nvidia GPUs compared to using only CPUs. When running a multithreaded Geant4 ATLAS test beam application with full hadronic physics, using Celeritas to accelerate the EM physics results in an overall simulation speedup of 1.8–2.3× on GPU and 1.2× on CPU.

Johnson, Seth R.↗

NASA NTRS1983

Electromagnetic levitation coil fabrication technique for MSFC containerless processing facilities

A technique is described for more reproducible fabrication of electromagnetic levitation coils. A split mandrel was developed upon which the coil is wound. After fabrication the mandrel can be disassembled to remove it from the coil. Previously, a full day was required to fabricate a levitation coil and the success rate for a functional coil was only 50 percent. About eight coils may be completed in one day using the technique developed and 95 percent of them are good levitation coils.

Ethridge, E. C.↗