[en] In this report we present the design, electrical schemes and preliminary results of a test of 4 different electron plasma cathodes operating under Kg h-voltage pulses in a vacuum diode. The first plasma cathode consists of 6 azimuthally symmetrically distributed arc guns and a hollow anode having an output window covered by a metal grid. Plasma formation is initiated by a surface discharge over a ceramic washer placed between a W-made cathode and an intermediate electrode. Further plasma expansion leads to a redistribution of the discharge between the W-cathode and the hollow anode. An accelerating pulse applied between the output anode grid and the collector extracts electrons from this plasma. The operation of another plasma cathode design is based on Penning discharge for preliminary plasma formation. The main glow discharge occurs between an intermediate electrode of the Penning gun and the hollow anode. To keep the background pressure in the accelerating gap at P S 2.5x10⁴ Torr either differential pumping or a pulsed gas puff valve were used. The operation of the latter electron plasma source is based on a hollow cathode discharge. To achieve a sharp pressure gradient between the cathode cavity and the accelerating gap a pulsed gas puff valve was used. A specially designed ferroelectric plasma cathode initiated plasma formation inside the hollow cathode. This type of the hollow cathode discharge ignition allowed to achieve a discharge current of 1.2 kA at a background pressure of 2x10⁴ Torr. All these cathodes were developed and initially tested inside a planar diode with a background pressure S 2x10⁴ Torr under the same conditions: accelerating voltage 180 - 300 kV, pulse duration 200 - 400 ns, electron beam current - 1 - 1.5 kA, and cross-sectional area of the extracted electron beam 113 cm²

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[en] The results of the experimental studies on the formation of various structures on the cathode surface by sputtering in the glowing and magnetron discharges are presented. The cone-like, sheet and tubular formations are identified. The formation mechanism for evolution of these formations is proposed

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[en] Cathodic protection is intensively used on steel pipes in petroleum and gas industries. It is a technique used to prevent corrosion which transforms the whole pipe into a cathode of a corrosion cell. Two types of cathodic protection systems are usually used: 1) the galvanic protection systems which use galvanic anodes, also called sacrificial anodes being electrochemically more electronegative than the structure to be protected and 2) the imposed current systems, which through a current generator will deliver a direct current from the anode to the structure to be protected. The aim of this work is to design a cathodic protection system of a pipe by imposed current with auxiliary electric solar energy. (O.M.)

[en] Cathode spraying is one of the main factors specifying strategy of helium and neon lasers used as sensors for navigation systems of moving objects, planes, satellites, sea crafts and etc. A cold cathode of helium and neon laser operates under the conditions of continuous attack by neon and helium ions, which results in intensive spraying of its emissive surface. This paper describes application of different methods to increase resistance to the cathode spraying of beryllium and aluminum cold cathodes. A method of plasma and chemical surface treatment in glow discharge of oxygen under the cathode conditions is used for aluminum cathodes of helium and neon lasers. Optimal treatment conditions providing a high value of ion and electron emission rate (g= 0,14) and a decrease of emissive surface spraying capability by two times

[en] We have investigated the intensity of Cu 510.6 nm emission line in see-through Hollow Cathode Glow Discharge (st-HCGD) for the development of medical Cu vapor laser. In order to acquire the stable plasma in st-HCGD cell at high current, several factors such as current, the length and the inner diameter of cathode tube, the shape of the tube, and the range of the sputtering range were tested. An optimum condition in our st-HCGD cell was obtained at 600 V, 700 mA, 2.3 Torr of Ar gas (100 SCCM), and 40 mm of tube with 4-11-4 mm type cathode design. Also, it was indirectly observed that temperature in the cell could reach more than 1000 .deg. C since Cu cathode was melt at the current more than 700 mA (melting point of Cu, 1084 .deg. C)

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[en] The sputtering-atomising properties of a conventional flat bottom hollow cathode discharge (FBHCD) are analyzed. Furthermore, a modification of the HCD grounded on a conical bottom (CB) cylindrical cathode is reported. This CBHCD enhances the main HCD property, i.e. the sputtering of the surface of cathode or inserted probe. Comparative polarization measurements with a FBHCD show a stronger narrowing of the Hanle signal width for the sputtered Cu atoms with the CBHCD. Thus, their density is higher in CBHCD. This result is confirmed by the opto-galvanic radial profile. It contains two peaks of the mentioned density, i.e. near the cylindrical cathode surface and over the cone peak. Some preliminary examinations of CBHCD as an ion source in three arrangements are performed and discussed

No abstract available