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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Design of a Second Generation Electrostatic Precipitator for Martian Atmospheric Dust Mitigation of ISRU Intakes

A second generation electrostatic precipitator for use in the Martian environment has been developed by the Electrostatics and Surface Physics Laboratory (ESPL) at NASA Kennedy Space Center (KSC). This new system was designed to be modular and has three interchangeable test sections, each with a variety of replaceable high voltage electrodes, enabling optimization of the dust collection efficiency of the precipitator. It has the ability to maintain an increased atmospheric flow rate and provide more accurate dust delivery into the test section than was available in the previous prototypes. A majority of the controls for the system are provided by a software package developed to maintain a constant flow rate, low pressure, and electrode current to enable long duration performance characterization. This allows for testing of the technology in a relevant environment similar to those expected to be found in an atmospheric In-Situ Resource Utilization (ISRU) plant on Mars.

Precipitator↗
NASA NTRS2018

Dust Mitigation on Mars Using an Electrostatic Precipitator

The Martian atmosphere contains large amounts of dust, which are lofted by dust devils and dust storms. Some of this dust, particles on the order of 2-4 m, never settle and are constantly present in the atmosphere. Therefore, in order to utilize the planet's atmosphere for production of consumables, like oxygen and methane, this dust must be removed before the commodity production can begin. The electrostatic precipitator is currently being studied at Kennedy Space Center as a realistic option for removing this dust. This project covers the results, to date, of the dust flow initiation, control, and analysis inside the electrostatic precipitator, which is to be modelled after various dusty Martian atmospheric conditions.

electrostatic precipitator↗
NASA NTRSDate not supplied

Electrostatic Charging of the Lunar Surface

Lunar regolith dust particles accumulate charge and interact electrostatically with rover wheels, astronaut boots, and equipment. We have developed instrumentation for in situ measurements of the electrostatic charge developed by the interactions of lunar regolith dust with the space-rated materials on these devices. This instrument is also capable of measuring the distribution of electric fields on or near the lunar surface and the ion currents present near the lunar surface. We also report on our efforts to characterize the charging behavior of lunar dust in low gravity environments. This behavior is nonintuitive due to complex interactions between individual dust grains. We are developing an experiment to study this interaction in a microgravity vacuum environment. Better understanding of this interaction will allow for improved dust mitigation on the lunar surface.

electrostatics↗
NASA NTRSDate not supplied

Electrostatic charging of the lunar regolith

Lunar regolith dust particles accumulate charge and interact electrostatically with rover wheels, astronaut boots, and equipment. We have developed instrumentation for in situ measurements of the electrostatic charge developed by the interactions of lunar regolith dust with the space-rated materials on these devices. This instrument is also capable of measuring the distribution of electric fields on or near the lunar surface and the ion currents present near the lunar surface. We also report on our efforts to characterize the charging behavior of lunar dust in low gravity environments. This behavior is nonintuitive due to complex interactions between individual dust grains. We are developing an experiment to study this interaction in a microgravity vacuum environment. Better understanding of this interaction will allow for improved dust mitigation on the lunar surface.

electrostatics↗
NASA NTRS2023

Effect of the Electrostatic Field due to the Surface Monolayer Metal Atoms on the Dissociation of Homonuclear Diatomic Gases in Gas-Metal Surface Reactions

The present paper examines the role of an electrostatic field generated by the outermost monolayer of metal ions prior to gas adsorption in aiding the dissociation of homonuclear diatomic gas molecules. The interaction of five homonuclear diatomic gases, Cl 2 , F 2 , H 2 , N 2 and O 2 , with several pure metals are examined using Coulomb’s law to calculate the attractive and repulsive forces between the electrons or ions in the gas molecule and the free surface metallic electrons or ions assuming a Bohr model. These calculations demonstrate that the total energy of the electrostatic fields from the metals can exceed the molecular binding energies of Cl 2 , F 2 , and O 2 at some distance from the metallic surface thereby suggesting that these gases interact primarily with the metallic surface in their atomic states after molecular bond dissociation prior to reaction. In contrast, H 2 and N 2 gases do not dissociate prior to reaching the metal surface due to the fact that the effective charge of the gas ions is less than the total electron charge at the outermost electronic shell. The present results correlate linearly with the electrochemical series standard reduction potential as well as with the Pauling electronegativity for several metals.

Gas-metal reactions↗
NASA NTRS1965

Vibrating diaphragm measures high electrostatic field strengths

Meter with flexible conductive diaphragm measures electrostatic charge density on a conducting surface in a vacuum. The diaphragm is supported from an insulated conductive support ring rigidly attached to the conductive surface whose electrostatic charge density is to be measured.

Source record↗
NASA NTRS1969

Electrostatic displays

Display devices using electrostatic forces, discussing electrostatic printing, magnetic display system, etc

Rice, P.↗
NASA NTRS1971

Electrostatic, short-wavelength, turbulence as the source of ion heating in the solar wind

A mechanism is proposed for the nonthermal ion heating observed in the solar wind at 1 A.U. based on an electrostatic, short wavelength, instability between the ions in the observed colliding plasma streams. The modes lying on a plane perpendicular to the magnetic field thermalize most of the differential energy. The model suggests local electrostatic turbulence, that alpha-particles are heated more than protons, a maximum proton temperature T sub P 1 million k, and for the bulk speed U possibly a sq root of T sub P = aU + b relationship. These predictions are consistent with observations.

Papadoupoulis, K.↗
NASA NTRS1971

Current driven electrostatic and electromagnetic ion cyclotron instabilities

Growth rates and parameter dependences are calculated for the current driven instabilities of electrostatic (with finite-beta corrections) and electromagnetic ion cyclotron waves. For 0.25 (T sub e)/(T sub i) 2.5, ion cyclotron waves have large growth rates, while ion acoustic waves are still stable. In fusion devices, where electrostatic waves may be stable, electromagnetic ion cyclotron waves are unstable for beta sub i 0.001.

Forslund, D. W.↗
NASA NTRS1971

Thin electrostatically self-focusing electron streams.

Study of 30 to 380 microampere, 50 to 550 V, 1 to 2 mm, electrostatically self-focusing electron streams (50 cm long) drifting through mercury vapor (at 50 microtorr to 2 millitorr) in a tube with a radius of 6.6 cm. The inside surface of the tube is coated with a transparent layer whose resistivity is 50 ohm-cm per centimeter. In order to determine the charged-particle densities and the potential profile in and around the beam without disturbing the system, a multigrid electrostatic charged particle energy analyzer was used to study separately the energy distributions of both ions and electrons ejected radially from the beam. The results show two energy groupings for electrons. The energy distribution of the high-energy group is produced by ionizing collisions between beam electrons and neutral gas atoms; a group of flow-energy electrons becomes trapped in the potential well within and around the beam, subsequently escaping by collisional mechanisms.

Mccorkle, R. A.↗
NASA NTRS1972

Electrostatic camera system functional design study

A functional design study for an electrostatic camera system for application to planetary missions is presented. The electrostatic camera can produce and store a large number of pictures and provide for transmission of the stored information at arbitrary times after exposure. Preliminary configuration drawings and circuit diagrams for the system are illustrated. The camera system's size, weight, power consumption, and performance are characterized. Tradeoffs between system weight, power, and storage capacity are identified.

Botticelli, R. A.↗
NASA NTRS1972

Electrostatic waves in the magnetosphere.

Electric dipole antennas on magnetospheric spacecraft measure E field components of many kinds of electromagnetic waves. In addition, lower hybrid resonance emissions are frequently observed well above the ionosphere. The Ogo 5 plasma wave experiment has also detected new forms of electrostatic emissions that appear to interact very strongly with the local plasma particles. Greatly enhanced wave amplitudes have been found during the expansion phases of substorms, and analysis indicates that these emissions produce strong pitch angle diffusion. Intense broadband electrostatic turbulence is also detected at current layers containing steep magnetic field gradients. This current-driven instability is operative at the bow shock and also at field null regions just within the magnetosheath, and at the magnetopause near the dayside polar cusp. The plasma turbulence appears to involve ion acoustic waves, and the wave particle scattering provides an important collisionless dissipation mechanism for field merging.

Scarf, F. L.↗
NASA NTRS1973

Effects of electrostatic instabilities on planetary and interstellar ions in the solar wind.

It is shown that newly born ions in the solar wind result in unstable electrostatic waves propagating parallel and perpendicular to the interplanetary magnetic field. A description of the longitudinal instability is followed by a discussion of its implications for assimilating newly born ions of interstellar and planetary origin into comotion with the solar wind bulk velocity. The transverse electrostatic instability is then considered and it is shown that its growth rate is of the same order as that for transverse electromagnetic instabilities found by Wu and Davidson (1972).

Hartle, R. E.↗
NASA NTRS1973

Diffusion of ring current particles by low-frequency long-wavelength electrostatic oscillations.

The diffusion of charged particles by randomly fluctuating low-frequency long-wavelength electrostatic oscillations in the magnetosphere is investigated as a possible mechanism for transporting ring current particles. The diffusion process is assumed to preserve the first adiabatic invariant. The magnetosphere is represented by a simple model with cylindrical geometry. In the model the ionospheres are assumed to be perfectly conducting and the ring current is assumed to have a Maxwellian distribution of velocities. The electrostatic oscillations are treated as natural modes of the magnetospheric cavity which are driven by variations in the electric potential on the magnetopause. It is concluded that diffusion of ring current protons by this process is not important in the magnetosphere.

Maggs, J. E.↗
NASA NTRS1974

A theoretical and experimental investigation of cylindrical electrostatic probes at arbitrary incidence in flowing plasma

The theory for calculating the current collected by a negatively biased cylindrical electrostatic probe at an arbitrary angle of attack in a weakley ionized flowing plasma is presented. The theory was constructed by considering both random and directed motion simultaneous with dynamic coupling of the flow properties and of the electric field of the probe. This direct approach yielded a theory that is more general than static plasma theories modified to account for flow. Theoretical calculations are compared with experimental electrostatic probe data obtained in the free stream of an arc-heated hypersonic wind tunnel. The theoretical calculations are based on flow conditions and plasma electron densities measured by an independent microwave interferometer technique. In addition, the theory is compared with laboratory and satellite data previously published by other investigators. In each case the comparison gives good agreement.

Jenkins, R. V.↗
NASA NTRS1973

Electrostatic transportation of dust on the moon

There is much evidence that the surface transportation of lunar soil has been a major process in the shaping of the lunar surface. Some such transportation has taken place as a result of meteoritic impacts, but theory and laboratory experiments indicate that electrostatic effects resulting from secondary electron emission are the dominant cause of movement of small grains on the surface. The various electrostatic actions are discussed, and a host of unexpected phenomena are described that have turned up in the course of the laboratory experiments.

Gold, T.↗