Results 171 to 180 of about 425 (216)
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Transactions of the IRE Professional Group on Electron Devices, 1953
The properties of a cathode consisting of an internally coated hollow shell with an aperture have been measured for a variety of geometries. Electrons are emitted from the edge of the aperture at current densities as high as 30 amp/sq cm. The cathode is particularly adapted to producing hollow or odd-shaped electron beams.
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The properties of a cathode consisting of an internally coated hollow shell with an aperture have been measured for a variety of geometries. Electrons are emitted from the edge of the aperture at current densities as high as 30 amp/sq cm. The cathode is particularly adapted to producing hollow or odd-shaped electron beams.
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1974
Publisher Summary This chapter provides an overview of hollow cathode arcs (HCA). Hollow cathodes have been used for some years in different discharge devices, working under varying conditions in widely extended ranges. All of these devices have one common feature: the cathode presents a hollow cavity, enclosed or at least partially bound by walls ...
Jean-Loup Delcroix +1 more
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Publisher Summary This chapter provides an overview of hollow cathode arcs (HCA). Hollow cathodes have been used for some years in different discharge devices, working under varying conditions in widely extended ranges. All of these devices have one common feature: the cathode presents a hollow cavity, enclosed or at least partially bound by walls ...
Jean-Loup Delcroix +1 more
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Centrospazio Progress on MPDT Hollow Cathodes
40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2004The paper deals with Alta-Centrospazio progress in the frame of the numerical activity on high-current hollow cathodes for MPD thrusters applications, started about three years ago with the development of a stationary, one-dimension single-channel hollow cathode model.
ROSSETTI P. +3 more
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SYNTHESIS OF FULLERENES BY HOLLOW CATHODE ARC
Fullerenes, Nanotubes and Carbon Nanostructures, 2002The formation of fullerenes in a hollow cathode arc in an inert gas atmosphere is investigated. The effects of the carbon evaporation rate, the inert gas flow rate and the arc temperature on the fullerene yield, production rate and conversion rate are observed.
Marković, Zoran M. +2 more
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Pre-Breakdown Processes in the Hollow Cathode Region of a Transient Hollow Cathode Discharge
Astrophysics and Space Science, 1997Discharge formation in the A–K space of transient hollow cathode discharge (THCD) is causally linked with the emission of high energy electron beams originating in the hollow cathode region (HCR). Ionization in the A–K gap proceeds through the formation of a moving virtual anode, whose time evolution is strongly correlated with different periods in the
M. Favre +6 more
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Pulsed Hollow Cathode Discharge Characteristics
2007 IEEE Pulsed Power Plasma Science Conference, 2007Hollow electrode structures are used in many applications to produce high intensity glow discharges. They provide high current densities at lower voltages compared to planar geometries. In this study, pulsed hollow cathode effects are investigated. Setup consists of hollow copper electrodes with 1.6 cm diameter cavity and a pulsed trigger unit attached
Esin B. Sozer +2 more
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Journal of Electronics and Control, 1964
Abstract In this paper the hollow cathode effect is discussed in connection with the derivation of some simple laws which relate the current density, j, the gas pressure, p, and the current amplification factor, q. Thus one may conclude that, under the conditions of a fully developed hollow cathode effect, the product I2p does not depend on the gas ...
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Abstract In this paper the hollow cathode effect is discussed in connection with the derivation of some simple laws which relate the current density, j, the gas pressure, p, and the current amplification factor, q. Thus one may conclude that, under the conditions of a fully developed hollow cathode effect, the product I2p does not depend on the gas ...
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Analytical Chemistry, 1992
Sputtering changes the analytical performance of the hollow cathode as an emission source. Proper conditioning (aging) of the hollow with sputtering greatly improves precision. Conditioning decreases the blank emission signal and changes the shape of the hollow.
J L, Tseng +3 more
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Sputtering changes the analytical performance of the hollow cathode as an emission source. Proper conditioning (aging) of the hollow with sputtering greatly improves precision. Conditioning decreases the blank emission signal and changes the shape of the hollow.
J L, Tseng +3 more
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Hollow cathodes for arcjet thrusters
19th International Electric Propulsion Conference, 1987In an attempt to prevent exterior spot emission, hollow cathode bodies and orifice plates were constructed from boron nitride which is an electrical insulator, but the orifice plates melted and/or eroded at high interelectrode pressures. The most suitable hollow cathodes tested included a refractory metal orifice plate in a boron nitride body, with the
CRAIG LUEBBEN, PAUL WILBUR
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A Study of Hollow Cathode Discharge Characteristics
AIAA Journal, 1970The operation and performance of small-orifice hollow cathodes for use in electron bombardment ion thrusters is described. Using mercury propellant, vaporized either in a small boiler or by a heated porous plug, cathodes have been operated in both a simple test facility and in an ion thruster.
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