186
186
May 27, 2011
05/11
by
GRIGORYEV, B. V
texts
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THIS PAPER TREATS OF THE HYDRAULIC FORMING OF THIN METAL DIAPHRAGM MATERIAL. THE METHOD CONSIDERED GIVES CONSIDERABLY MORE STABLE PROPERTIES AND LESS RESIDUAL DEFORMATIONS, ELASTIC FATIGUE, AND HYSTERESIS CONSIDERATION IS GIVEN TO THE PROBLEM OF THE PRESSURE NECESSARY FOR FORMING THE DIAPHRAGM AND UTILIZING THIS PRESSURE TO REINFORCE THE CLAMPING PRESSURE OF THE BLANK AGAINST THE RIM.
Topics: ARC DISCHARGES, DIRECT CURRENT, PLASMAS (PHYSICS), HIGH FREQUENCIES, AGREEMENTS
192
192
Jun 21, 2010
06/10
by
OTTLIK, P
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ULTRASONIC WAVE PROPAGATION IN CARBONACEOUS AND SILICEOUS ROCKS
Topics: ARC DISCHARGES, ARC WELDING, ELECTRON BEAM WELDING, ELECTRIC ARCS, PRODUCT DEVELOPMENT
292
292
Jul 11, 2010
07/10
by
Hardee, S. N
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The Apollo spacecraft and the Soyuz spacecraft used for the Apollo Soyuz Test Project are described along with the tracking and communications networks utilized for the mission. The flight is briefly summarized including: launch, rendezvous, and docking maneuvers; crew transfer and joint and unilateral experiments; Soyuz deorbit and landing; and Apollo orbit continuation, deorbit, and landing.
Topics: ARC DISCHARGES, INTERNAL COMBUSTION ENGINES, SPARK IGNITION, AUTOMOBILES, PULSE DURATION, SYSTEMS...
403
403
May 22, 2011
05/11
by
Kaaret, Philip; Chen, Andre
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The goal of this research program was to develop a novel technique for focusing x-rays based on the optical system of a lobster's eye. A lobster eye employs many closely packed reflecting surfaces arranged within a spherical or cylindrical shell. These optics have two unique properties: they have unlimited fields of view and can be manufactured via replication of identical structures. Because the angular resolution is given by the ratio of the size of the individual optical elements to the...
Topics: ARC DISCHARGES, ELECTRIC ARCS, SPACE DEBRIS, SPACE PLASMAS, SPACECRAFT CHARGING, CAPACITANCE, SPACE...
345
345
Jul 5, 2010
07/10
by
Lipschitz, A.; Lucas, D
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No Abstract Available
Topics: ARC DISCHARGES, DIRECT CURRENT, PRESSURE EFFECTS, LINE SPECTRA, LITHIUM, LUMINOUS INTENSITY,...
224
224
Jul 6, 2010
07/10
by
Vinogradov, I. B.; Kobrinskiy, A. Y.; Stepanenko, Y. A.; Tyves, L. I
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A volumetric method of kinematic analysis of a manipulator which can be used in addition to the conventional trajectory method is presented. An ideal manipulator, the influence of limitations on the angles of rotation of the manipulator, and a manipulator with limitations in all joints are discussed.
Topics: ARC HEATING, NOZZLE FLOW, SHOCK TUNNELS, TEST FACILITIES, ARC DISCHARGES, ENTHALPY, GAS DYNAMICS,...
309
309
Jul 12, 2010
07/10
by
Lauffer, J. R
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No Abstract Available
Topics: MAGNETOPLASMADYNAMICS, PERFORMANCE TESTS, ROCKET ENGINES, SPACECRAFT DESIGN, ARC DISCHARGES,...
A metal halide arc discharge lamp includes a sealed light-transmissive outer jacket, a light-transmissive shroud located within the outer jacket and an arc tube assembly located within the shroud. The arc tube assembly includes an arc tube, electrodes mounted within the arc tube and a fill material for supporting an arc discharge. The electrodes have a spacing such that an electric field in a range of about 60 to 95 volts per centimeter is established between the electrodes. The diameter of the...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, JACKETS, LUMINAIRES, METAL HALIDES, SHROUDS,...
The present study details the high-power condensable propellant research being conducted at NASA Glenn Research Center. The gallium electromagnetic thruster is an ablative coaxial accelerator designed to operate at arc discharge currents in the range of 10-25 kA. The thruster is driven by a four-parallel line pulse forming network capable of producing a 250 microsec pulse with a 60 kA amplitude. A torsional-type thrust stand is used to measure the impulse of a coaxial GEM thruster. Tests are...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, GALLIUM, VACUUM CHAMBERS, PROPELLANTS,...
High voltage is applied to an arc gap adjacent to a test specimen to develop a succession of high frequency arc discharges. Those high frequency arc discharges generate pulses of ultrasonic energy within the test specimen without requiring the arc discharges to contact that test specimen and without requiring a coupling medium. Those pulses can be used for detection of flaws and measurements of certain properties and stresses within the test specimen.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, PULSE GENERATORS, ULTRASONIC TESTS, HIGH...
387
387
May 6, 2010
05/10
by
Jedlicka, J. R
texts
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Shape of electric arc discharge rotated in annular gap by external magnetic field
Topics: ANNULI, SPARK GAP, ARC DISCHARGES, ELECTRIC ARCS, MAGNETIC FIELDS, SHAPES, SPARK GAPS, ARC...
One cathode includes array of square-shaped conductor columns. Columns are electrically interconnected by conducting plate on bottom. Each column provides field-emission current. Another cathode includes array of rodlike conductors. Layer is covered by control film made of conducting material. Film is isolated from each conductor.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CATHODES, ELECTRICAL FAULTS, FIELD EMISSION,...
A double-ended arc discharge lamp includes a sealed, light-transmissive outer jacket, a light-transmissive shroud mounted within the outer jacket and directly supported by the outer jacket, and an arc discharge tube mounted within the shroud. The arc tube is typically a metal halide arc discharge tube. In a preferred embodiment, the shroud includes an outwardly flared portion at each end. The outwardly flared portions space the shroud from the outer jacket and support the shroud within the...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CONTAINMENT, JACKETS, LUMINAIRES, METAL...
A double-ended arc discharge lamp includes a sealed, light-transmissive outer jacket, a light-transmissive shroud mounted within the outer jacket and directly supported by the outer jacket, and an arc discharge tube mounted within the shroud. The arc tube is typically a metal halide arc discharge tube. In a preferred embodiment, the shroud includes an outwardly flared portion at each end. The outwardly flared portions space the shroud from the outer jacket and support the shroud within the...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CONTAINMENT, JACKETS, LUMINAIRES, METAL...
491
491
May 23, 2011
05/11
by
Onwubiko, Chin-Yere; Onyebueke, Lando
texts
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Structural failure is rarely a ''sudden death'' type of event, such sudden failures may occur only under abnormal loadings like bomb or gas explosions and very strong earthquakes. In most cases, structures fail due to damage accumulated under normal loadings such as wind loads, dead and live loads. The consequence of cumulative damage will affect the reliability of surviving components and finally causes collapse of the system. The cumulative damage effects on system reliability under...
Topics: HOLLOW CATHODES, XENON, RELIABILITY, IGNITION, INTERNATIONAL SPACE STATION, ACCELERATED LIFE TESTS,...
A sustained-arc ignition system was developed for internal combustion engines. It produces a very-long-duration ignition pulse with an energy in the order of 100 millijoules. The ignition pulse waveform can be controlled to predetermined actual ignition requirements. The design of the sustained-arc ignition system is presented in the report.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, INTERNAL COMBUSTION ENGINES, SPARK IGNITION,...
A technique for measuring hypersonic flow velocity profiles is described. This technique utilizes an arc-discharge-electron-beam system to produce a luminous disturbance in the flow. The time of flight of this disturbance was measured. Experimental tests were conducted in the Langley pilot model expansion tube. The measured velocities were of the order of 6000 m/sec over a free-stream density range from 0.000196 to 0.00186 kg/cu m. The fractional error in the velocity measurements was less than...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, HYPERSONIC FLOW, VELOCITY DISTRIBUTION,...
The electrical characteristics of a high-power, long-lived, free-burning dc argon arc are presented. Empirical formulas relating voltage to current, electrode separation, and operating pressure are given for two types of cathodes: a typical point tip cathode and a cathode with a 1.27-cm-(0.5-in.-) diameter crater in the tip. Power was varied from 90 to 563 kW. A discussion of the cathode with the crater tip is given.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ARGON, CATHODES, DIRECT CURRENT, ANODES,...
Circuitry for maintaining an arc or spark across a spark gap for a desired length of time is disclosed. A high voltage, direct current source is connected in series with a secondary winding of a high voltage, stepup transformer or coil and a spark gap such as a spark plug for example. The high voltage source may be on continuously or may be turned on and off by a control circuit such as a solid state switch which is, in turn, responsive to a timing device such as a set of ignition contact...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, HIGH VOLTAGES, IGNITION SYSTEMS, SWITCHING...
287
287
May 23, 2011
05/11
by
Wood, Brian E.; Alexander, William R.; Linsky, Jeffrey L
texts
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We present new observations of the Ly alpha lines of Epsilon Indi (K5 5) and A Andromedae (G8 4-3 ) These data were obtained by the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. Analysis of the interstellar H 1 and D 1 absorption lines reveals that the velocities and temperatures inferred from the H 1 lines are inconsistent with the parameters inferred from the D 1 lines, unless the H 1 absorption is assumed to be produced by two absorption components. One...
Topics: PHOTOVOLTAIC CELLS, PLASMA INTERACTIONS, SOLAR ARRAYS, SPACE PLASMAS, INTERNATIONAL SPACE STATION,...
Space environmental effects have caused severe problems as satellites move toward increased power and operating voltage levels. The greatest unknown, however, is the effect of high velocity micrometeoroid impacts on high voltage arrays (>200V). Understanding such impact phenomena is necessary for the design of future reliable, high voltage solar arrays, especially for Space Solar Power applications. Therefore, the objective of this work was to study the effect of hypervelocity impacts on...
Topics: NASA Technical Reports Server (NTRS), HYPERVELOCITY IMPACT, SOLAR ARRAYS, ARC DISCHARGES,...
A parallel-rail arc-discharge system to heat and pressurize the initial helium driver gas of the Langley 6-inch expansion tube is described. This system was designed for a 2.44-m-long driver vessel rated at 138 MPa, with a distance between rails of 20.3 cm. Electric energy was obtained from a capacitor storage system rated at 12,000 V with a maximum energy of 5 MJ. Tests were performed over a range of energy from 1.74 MJ to the maximum value. The operating experience and system performance are...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, GAS EXPANSION, HELIUM, SHOCK TUBES, CARBON...
A study was made of the effect of arc length, cathode thickness, current strength, gas pressure and the chemical nature of the cathode material and filling gases upon the material loss from Cu, Fe, and Ag cathodes in arcs. The results show that the analysis of the phenomenon is complex and the energy balance is difficult to formulate.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CATHODES, COPPER, GAS PRESSURE, IRON, SILVER,...
Spectroscopic and photographic investigations are reported that reveal a complex azimuthal species structure in the exhaust plume of a quasi-steady argon MPD accelerator. Over a wide range of operating conditions the injected argon remains collimated in discrete jets which are azimuthally in line with the six propellant injector orifices. The regions between these argon jets, including the central core of the exhaust flow, are occupied by impurities such as carbon, hydrogen and oxygen ablated...
Topics: NASA Technical Reports Server (NTRS), ARGON PLASMA, ELECTROMAGNETIC PROPULSION, EXHAUST GASES,...
Arcing and other types of electrical discharges are likely to occur in high-voltage subsystems of the Space Station. Results from ground and space experiments on the arcing of solar cell arrays are briefly reviewed, showing that the arcing occurs when the conducting interconnects in the arrays are at negative potential above a threshold, which decreases with the increasing plasma density. Furthermore, above the threshold voltages the arcing rate increases with the plasma density. At the...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE ENVIRONMENTS, ARC DISCHARGES, ELECTRIC DISCHARGES,...
The time dependence of the emitted currents during arcing on solar cell arrays is being studied. The arcs are characterized using three parameters: the voltage change of the array during the arc (i.e., the charge lost), the peak current during the arc, and the time constant describing the arc current. This paper reports the dependence of these characteristics on two array parameters, the interconnect bias voltage and the array capacitance to ground. It was found that the voltage change of the...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CAPACITANCE, PLASMA INTERACTIONS, SOLAR...
A quasi-steady MPD accelerator has been operated with four different hollow cathodes over a power range from 5 kilowatts to 5 megawatts. The absolute level of the argon mass flow, as well as the fractional division of the flow between the cathode and the six standard chamber injectors, is varied over a range of 1 to 12 grams per second. For a fixed total current, it is observed that the voltage increases monotonically with mass flow rate, compared to the usual experience with solid cathodes...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, HOLLOW CATHODES, PLASMA ACCELERATORS, PLASMA...
The exhaust of the source flowing into vacuum was measured by Thomson scattering diagnosis. Mean electron temperatures and densities were found to be 4-8 eV and of order ten to the 13th power cm/3 respectively over the 8 cm exhaust diameter at 30 cm from the source. Large shot to shot variations were noted. After a transient spike passes, these conditions persist during the power time of 125 microsecond. These exhaust conditions are marginal for evaluation of a proposed near resonant charge...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, PLASMA DIAGNOSTICS, PULSED LASERS, THOMSON...
This document outlines arc tracking signals -- both the data acquisition and signal processing. The objective is to obtain the salient features of the arc tracking phenomenon. As part of the signal processing, the power spectral density is obtained and used in a MATLAB program.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, DATA ACQUISITION, ELECTRIC ARCS, POWER...
The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, MATHEMATICAL MODELS, PLASMA ARC WELDING,...
Arcing due to spacecraft charging on spacecraft EMI margins of immunity was determined. The configuration of the P78-2 spacecraft of the SCATHA program was analyzed. A brushfire arc discharge model was developed, and a technique for initiating discharges with a spark plug trigger was for data configuration. A set of best estimate arc discharge parameters was defined. The effects of spacecraft potentials in limiting the discharge current blowout component are included. Arc discharge source...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, COUPLING COEFFICIENTS, ELECTROSTATIC...
Repetitively pulsed plasma jets generated by a capillary arc discharge at high stagnation pressure (>15,000 psi) and high temperature (>10,000 K) are utilized to produce 0.1-10 .mu.m sized metal powders and decrease cost of production. The plasma jets impact and atomize melt materials to form the fine powders. The melt can originate from a conventional melt stream or from a pulsed arc between two electrodes. Gas streams used in conventional gas atomization are replaced with much...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, HIGH PRESSURE, HIGH TEMPERATURE, METAL...
Serious problems can occur from insulation failures in the wiring harnesses of aerospace vehicles. In most recorded incidents, the failures have been identified to be the result of arc tracking, the propagation of an arc along wiring bundles through degradation of insulation. Propagation of the arc can lead to the loss of the entire wiring harness and the functions which it supports. While an extensive database of testing for arc track resistant wire insulations has been developed for aircraft...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE VEHICLES, ARC DISCHARGES, ELECTRICAL INSULATION,...
A simple optical setup has been devised to enable safe viewing of the arc and measurement of the interelectrode gap in a process in which carbon nanotubes are produced in an arc between a catalyst-filled carbon anode and a graphite cathode. This setup can be used for visually guided manual positioning of the anode to maintain the interelectrode gap at a desired constant value, possibly as a low-technology alternative to the automatic position/voltage control described in Automatic Control of...
Topics: NASA Technical Reports Server (NTRS), CARBON NANOTUBES, VISUAL OBSERVATION, ELECTRIC POTENTIAL, ARC...
The results are presented of Kapton wire arc tracking tests performed at NASA-Johnson in 1990 using test procedure KWATT BB01. The tests were performed to gather data for use in assessing the safety of the Space Shuttle Orbiter wiring which is predominantly Kapton insulated.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CIRCUIT PROTECTION, ELECTRIC ARCS, ELECTRIC...
A quantitative assessment of the hazard associated with spacecraft charging and arcing on spacecraft systems is presented. A literature survey on arc discharge thresholds and characteristics was done and gaps in the data and requirements for additional experiments were identified. Calculations of coupling of arc discharges into typical spacecraft systems were made and the susceptibility of typical spacecraft to disruption by arc discharges was investigated. Design guidelines and recommended...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, SAFETY MANAGEMENT, SPACECRAFT CHARGING,...
A low-energy gallium plasma source is used to perform a spatially and temporally broad spectroscopic survey in the 220-520 nm range. Neutral, singly, and doubly ionized gallium are present in a 20 J, 1.8 kA (peak) arc discharge operating with a central cathode. When the polarity of the inner electrode is reversed the discharge current and arc voltage waveforms remain similar. Utilizing a central anode configuration, multiple Ga lines are absent in the 270-340 nm range. In addition, neutral and...
Topics: NASA Technical Reports Server (NTRS), GALLIUM, PLASMAS (PHYSICS), ELECTRIC POTENTIAL, CATHODES, ARC...
An analysis is made of the electrophysical processes occurring at the end surface of rod electrodes during constant and alternating arc discharge in hydrogen. Experiments are reported on the effect of surface temperature of tungsten electrodes on their erosion. The influence of activating additions of thorium oxide, the structure of the tungsten, and the gas surrounding the electrode on the specific thermal loading and the erosion of the electrodes is discussed.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, DISINTEGRATION, ELECTRODE MATERIALS,...
Arcs representative of those occurring between the grids of a mercury ion thruster were simulated. Parameters affecting an arc and the resulting damage were studied. The parameters investigated were arc energy, arc duration, and grid geometry. Arc attenuation techniques were also investigated. Potentially serious damage occurred at all energy levels representative of actual thruster operating conditions. Of the grids tested, the lowest open-area configuration sustained the least damage for...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ELECTRIC ARCS, ION ACCELERATORS, ION...
Proposals are now being developed for the construction of high-power photovoltaic systems for operation in low Earth orbit, where the plasma number density is about 1,000 to 1,000,000 per cubic cm. Existing data indicate that interactions between the plasma and high-voltage surfaces of an orbiting power system will occur. In ground tests, where the applied voltage is increased negatively from ground, the array current collection shows an approximately linear rise until it terminates in arcing...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, DIELECTRICS, ELECTRIC CONDUCTORS, SOLAR...
365
365
Jul 26, 2010
07/10
by
Arif, Hug
texts
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The COLD-SAT free-flying spacecraft was to perform experiments with LH2 in the cryogenic fluid management technologies of storage, supply and transfer in reduced gravity. The Phase A preliminary design of the Thermal Control Subsystem (TCS) for the spacecraft exterior and interior surfaces and components of the bus subsystems is described. The TCS was composed of passive elements which were augmented with heaters. Trade studies to minimize the parasitic heat leakage into the cryogen storage...
Topics: ARC DISCHARGES, GEOMAGNETISM, MAGNETIC STORMS, MULTILAYER INSULATION, SPACECRAFT DESIGN, THREE...
A quartz hollow tube cathode was used to determine the operating conditions within a mercury orificed hollow cathode. Insert temperature profiles, cathode current distributions, plasma properties profile, and internal pressure-mass flow rate results are summarized and used in a phenomenological model which qualitatively describes electron emission and plasma production processes taking place within the cathode. By defining an idealized ion production region within which most of the plasma...
Topics: NASA Technical Reports Server (NTRS), ELECTRON EMISSION, HOLLOW CATHODES, ION PROPULSION,...
The properties of the arc discharges which are caused by the laboratory exposure of dielectric materials to electron beams are examined, the intent being to simulate conditions on synchronous-orbit spacecraft. Extensive experimental studies are reported for planar dielectrics (Teflon, Kapton, Mylar) on the subjects of incident-flux scaling of discharge properties and the effects of high-energy broad-spectrum electron irradiation from a radioisotpe source. In addition a preliminary evaluation is...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ELECTRON BOMBARDMENT, INSULATION, SPACECRAFT...
The mechanism of the high temperature Ar arc is interpreted considering those essential points in which it deviates from the known arcs based on earlier measurements and experiments. The following points are discussed individually: the charge carrier balance, the energy balance, the volt amp characteristics, and the difference between high temperature arcs in Ar and N. Besides the volt amp characteristic of a 10 mm long arc in Ar between 10 and 200 amp, the anode fall, cathode fall, and arc...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ARGON, ELECTRIC ARCS, PLASMA JETS, CHARGE...
A hollow cathode-based plasma contactor has been baselined for use on the Space Station to reduce station charging. The plasma contactor provides a low impedance connection to space plasma via a plasma produced by an arc discharge. The hollow cathode of the plasma contactor is a refractory metal tube, through which xenon gas flows, which has a disk-shaped plate with a centered orifice at the downstream end of the tube. Within the cathode, arc attachment occurs primarily on a Type S low work...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, CONTACTORS, HOLLOW CATHODES, SPACE PLASMAS,...
Development of a new test method suitable for the assessment of the resistance of aerospace cables to arc tracking for different specific environmental and network conditions of spacecraft is given in view-graph format. The equipment can be easily adapted for tests at different realistic electrical network conditions incorporating circuit protection and the test system works equally well whatever the test atmosphere. Test results confirm that pure Kapton insulated wire has bad arcing...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ELECTRIC ARCS, ELECTRIC EQUIPMENT TESTS,...
The ability of wire insulation materials and constructions to resist arc tracking was determined and the damage caused by initial arcing and restrike events was assessed. Results of arc tracking tests on various insulation constructions are presented in view-graph format. Arc tracking tests conducted on Champlain, Filotex, and Teledyne Thermatics indicate the Filotex is least likely to arc track. Arc tracking occurs more readily in air than it does in vacuum.
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ELECTRIC ARCS, ELECTRICAL INSULATION,...
A dc power supply for spacecraft arcjet thrusters has an integral automatic starting circuit and an output averaging inductor. The output averaging inductor, in series with the load, provides instantaneous current control, and ignition pulse and an isolated signal proportional to the arc voltage. A pulse width modulated converter, close loop configured, is also incorporated to give fast response output current control.
Topics: NASA Technical Reports Server (NTRS), ARC JET ENGINES, CIRCUITS, DIRECT CURRENT, SPACECRAFT POWER...
A model for the longitudinal variations of the partial pressures of electrons, ions, and neutral particles is proposed as a result of an experimental study of pressure variations at the level of the active zone as a function of the various discharge parameters of a hollow cathode arc. The cathode region where the temperature passes through its maximum is called active zone. The proposed model embodies the very important variations which the partial electron and neutral particles pressures...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ELECTRON DENSITY (CONCENTRATION), GAS...
The tasks performed can be divided into the following categories: an analysis of the electric arc phenomena, especially near the electrodes; a parametric study of arcjet performance by means of a computer code (ARCFLO) and verification with experimental data where possible; the development of a data acquisition system to collect the above experimental data using Ames arc-jets; and a study of the critical components (electrodes and constrictor disks) and suggestions of how to improve their...
Topics: NASA Technical Reports Server (NTRS), ARC DISCHARGES, ARC HEATING, ELECTRIC ARCS, ELECTRODES,...
