Showing papers on "Electric discharge published in 1971"

Electrochemical Processes in Glow Discharge at the Gas-Solution Interface

Abstract: The term electrolysis is conventionally applied to chemical changes brought about by passing an electric current between conducting electrodes dipping into a liquid phase containing ions, where the changes can be satisfactorily explained by electron transfer between the ions and the electrodes If, however, the liquid phase is itself made an electrode and an electrical glow-discharge is passed to it from a conductor located in the gas space above the surface, a completely different situation arises in which novel chemical reactions can be brought about in the liquid phase, and this process is referred to as glow-discharge electrolysis (GDE) It is worth emphasizing that it differs fundamentally from chemical decomposition brought about by electrical discharge between metallic electrodes in gases at low pressures, since in GDE, the reactions of interest are initiated in the liquid phase, and the quantity of electricity passed rather than electrical power dissipated is found to be the governing variable, as in conventional electrolysis

The propagation of electric discharges across the surface of an electrolyte

Abstract: Optical and electrical techniques have been used to investigate the way in which an electric discharge propagates across the surface of a liquid electrolyte. Field measurements have been carried out both in the column of the discharge, and beneath the liquid surface, by means of small metal probes. Schlieren photography has revealed a complex discharge structure and the presence of a strong liquid wave disturbance accompanying propagation. A significant difference in behaviour between positive and negative point discharges has been found. High speed cine-photography has shown that the speed of propagation of the discharge increases with voltage and with distance travelled and that this speed is influenced by resistive gradients in the electrolyte.

Cross‐Beam Electric‐Discharge Convection Laser

Abstract: An experimental investigation of a 60‐cm‐wide × 2.5‐cm‐high N2–CO2 cross‐beam electric‐discharge convection laser (EDCL) is described. Experiments relating to the achievement of uniform and stable discharges in the rectangular channel and measurements of laser optical properties are reviewed.

Quantitative analysis of the dependence of co2 laser performance on electric discharge properties

Abstract: Reported values of electron‐molecule energy transfer rate constants are combined with atom/molecule‐molecule and radiative energy transfer rate constants in an analysis of the conversion of electron energy to optical energy at 10.6μ in an electric discharge containing CO2, N2, and He. The small‐signal gain and the saturation intensity are calculated as functions of the electron density and gas temperature in the discharge. The calculated values of these quantities are consistent with experimentally determined values. The detrimental effect of high gas temperature on small‐signal gain is found to be the single most important factor influencing the efficiency of the discharge plasma as an energy conversion medium.

The cross-beam electric-discharge convection laser

Abstract: An experimental investigation of a 60-cm-wide × 2.5-cm-high N 2 -CO 2 cross-beam electric-discharge convection laser (EDCL) is described. In the cross-beam EDCL, the discharge is maintained along the flow in a rectangular cross-section channel and optical power is extracted transverse to the discharge and flow. High mass flow rates are employed to achieve high volumetric power densities. Experiments relating to the achievement of uniform and stable discharges at high-power levels in the rectangular laser channel, and measurements of the small-signal gain characteristics, amplifier performance, and optical quality are described. Using an 11-pass optical scheme, a CW optical output power of 2 kW has been extracted from the amplifier at an electrical efficiency of 9.6 percent.

Liquid cooled ozone generator

Abstract: An ozone generator module of the electirc discharge field type is provided having at least one cell comprising an assembly of three concentric tubular members, the inner and outer tubular members being electrodes separated by a tubular dielectric member spaced from one of the electrodes a distance sufficient to define a high density electric discharge zone between them, the cell or cells being disposed within a liquid container. Substantially optimum conditions for the production of ozone are provided by making the cross sectional dimension of the field uniform throughout to within a very small range of tolerance and by controlling the temperature of the electrodes by cooling them with liquid coolants one of which is a dielectric liquid, and limiting the density of the field by regulating the voltage across the field and the frequency employed.

Apparatus for electrostatic charging of paper in electrophotographic reproduction

Abstract: A corona discharge electrode is supplied with voltage from a high frequency power source to produce a corona discharge which strikes a sheet of reproducing paper to charge the same electrostatically. A detection electrode is positioned in the field of the corona discharge and is connected via a resistor and amplifier to the power source to control the same in accordance with the detected corona discharge to maintain the magnitude of the discharge field constant. A switch is connected in the power supply to interrupt connection thereof with the discharge electrode if a spark discharge is produced between the discharge electrode and the paper.

Carbon monoxide laser from helium-air-methane mixture

Abstract: A gas laser charged with a mixture of helium-air-methane, operable in both the Q-switched and CW mode, forms vibrationally excited CO molecules by the electric discharge induced chemical oxidation of methane. The resulting laser output provides at least 80 laser emission lines in the region from 4.7848 to 5.8532 microns, with 20 lines below 5 microns. Multiline pulse powers greater than two kilowatts may be obtained from the molecules formed by the electrochemical reaction. The lines result from P(J)v,v vibration-rotational transitions in the formed CO with J ranging from 10 to 15 nominally and v,v' ranging from 2:1 to 16:15. Simultaneous lasing of both the formed CO and CO2 molecules may be obtained by using two different temperatures of cooling (approximately -200 DEG C for one portion of the tube and approximately -80 DEG C for the remainder) of the laser tube to provide additional emission lines in the 9 to 13 micron range.

Stabilized, optimizable, gaseous electrical discharge

Abstract: A direct current (DC), transverse discharge, gaseous, slotted hollow cathode laser having an electrically indirectly heated oxidized tungsten, or molybdenum cathode, heated to thermionic emission in the presence of cesium vapor adsorbes cesium atoms and over a defined temperature range thermionic emission occurs in inverse proportion to the temperature of the cathode stabilizing the emission, precluding the formation of ''''hot spots,'''' and the relative low cathode fall voltage is varied providing an optimized amount of energy to the electrons as they are accelerated through the cathode fall voltage.

Magnetic stabilization of the plasma column in flowing molecular lasers

Abstract: A technique of magnetically stabilizing the position of the plasma column and the resulting inversion region in lower pressure flowing molecular lasers is described. A transverse magnetic field, mutually perpendicular to the discharge axial electric field and the gas flow velocity, is employed to maintain the electrical discharge column parallel with the optic axis. The magnetic stabilization of the discharge is analyzed in terms of the Lorentz forces and the resulting ambipolar drifts of the plasma. A comparison with magnetically stabilized arcs is presented. Supporting experimental data obtained for pure gases and typical laser gas mixtures are given. The operating characteristics of the cross-field CO 2 laser which employs a premixed gas flow channeled transverse to the stabilized discharge to provide convective gas cooling are discussed. The experimental results of a parametric study on the dependence of gain and power output upon gas flow velocities, magnetic field, gas mixtures, and pressure are presented. The operation of the first premixed CW electrically initiated chemical laser has been achieved using cross-field magnetic discharge stabilization. Preliminary operating characteristics of this chemical laser for the 3-µ rotational-vibrational transitions in HF and the 4-µ transitions in DF are presented.

Electrical discharges in liquid dielectrics

Abstract: The growth of an electrical discharge in transparent liquids can be observed using a simple shadowgraph technique. The photographic recordings resemble those obtained using the Lichtenberg technique. However, the shadowgraph system has the advantage that the test liquid is not disturbed by the recording medium. Preliminary observations reveal basic differences between the point-cathode and point-anode discharge phenomena.

Electrode wear compensating apparatus for an electrical discharge machine

Abstract: Apparatus for compensating the electrode wear in an electric discharge machine tool wherein an end of electrode travel signal is generated by actuation of a limit switch. The limit switch is actuated by a lead screw which is physically connected to the electrode holding means. The lead screw is moved a predetermined distance away from the limit switch by a motor means on each operation of the electrical discharge machine (EDM).

Glow discharge technique for the preparation of electrophotographic plates

Abstract: A method of preparing an electrophotographic plate having a metallic oxide coating interface is disclosed. The preparation of the plate involves subjecting a metallic substrate to a glow discharge process by utilizing it as the anode electrode in the electrical discharge process. The glow discharge effects oxidation of the surface as well as heating the substrate to a temperature at which vacuum evaporation of the photoconductive layer takes place. The process has particular utility because the glow discharge - oxidation process effectively cleans the metallic substrate thereby preparing it for the subsequent evaporation of a pure photoconductive material such as selenium.

Spot-knocking method for electronic tubes

Abstract: For spot-knocking a cathode ray tube including a first electrode adapted to be externally applied with a high operating voltage, a high voltage in excess of the operating voltage is supplied across the electrode and ground to cause an electric discharge within the tube while a second electrode disposed adjacent the first electrode between it and a cathode is connected to ground through a resistor. This leads to a flow of current through the resistor to cause another electric discharge across the second electrode and a third electrode adjacent it and grounded.

Flash discharge apparatus and method

Abstract: This disclosure involves novel flash tubes and similar electric discharge devices and methods comprising electrodes in a gaseous medium between which an electrical discharge is to pass and in which the reliability of repetitive operation is assured through the use of novel cooperative internal initiator conductor means and cooperative external conductive path means at opposite walls of the housing containing the gaseous medium.

Enhancement of laser output by nuclear reactions.

Abstract: Enhancement output power of CO-2 laser excited by electric discharge and irradiated by neutrons obtained from nuclear reactor

Aerodynamic large volume gaseous electric discharge system

Abstract: A large volume gaseous discharge system such as used in lasers has a plurality of electrodes at one end of the channel. A plurality of separate discharges are established adjacent the plurality of electrodes. A fast-moving gas stream within the channel aerodynamically controls the ion spacial distribution, and therefore indirectly the electron spacial distribution within the channel. In one system the geometry of the system and velocity of the stream are made such that the transit time between the plurality of electrodes at one end of the channel, and an electrode at the other end of the channel, is of the order of the diffusion time from one current stream and the next. In another embodiment rods are positioned to rapidly diffuse the plasma with nozzles provided to further aid in the mixing. A transverse folded optical path is used for laser operation.

Discharge lamp igniting circuit

Abstract: A discharge lamp igniting circuit in a discharge lamp of short tube length and capable of being ignited only by pre-heating a filament thereof, comprising a stabilizer winding having a secondary winding; a switching element connected to the discharge lamp at a terminal of one filament of said discharge lamp which is not connected to a power supply; and a diode connected to said secondary winding to keep said switching element conductive for at least one cycle until the discharge lamp is started; said secondary winding of the stabilizer winding, said filament of the discharge lamp, said switching element and said diode forming a closed loop to promote pre-heating of the filament and energize the stabilizer winding throughout all cycles by a short-circuit current flowing through the secondary winding, the switching element and the diode. With such a discharge lamp igniting circuit, a kick voltage produced at a time of ignition of the discharge lamp can be well prevented to eliminate possible darkening of the discharge lamp at its end portions.

High pressure electric discharge lamp

Abstract: The arc tube of an arc discharge lamp has two main electrodes and a starter electrode adjacent to one of them, the starter electrode being electrically connected to the other main electrode through a ceramic capacitor. The capacitance and voltage rating of the capacitor are such as to provide sufficient capacitive reactance for limiting the current to the starter electrode and to function as a direct current blocking capacitor during normal operation of the lamp.

Gas-discharge devices for optical pumping of lasers

Abstract: A gas-discharge device for optical pumping of lasers, in which a gas-filled chamber encloses an optically transparent laser-material holding tube and at least one optically transparent cylindrical discharge tube. This discharge tube is arranged inside the chamber so that the electrode assemblies between which an electric discharge is initiated to produce a gas-discharge plasma are found inside the discharge tube which has a slot to allow part of the plasma to spill over into the chamber.

Corona discharge laser

Abstract: A method of and apparatus for producing laser action in and transverse to a flowing gas over a wide range of flow and pressure conditions by an electrical discharge orthogonal to both the flow and lasing direction which is stabilized by electrode segmentation and ballasting.

Means for and method of stabilizing a plurality of gaseous electric arc discharge devices

Abstract: A method of and apparatus for providing stabilization of gaseous electric arc devices by effecting suitable changes in the voltage-versus-current (V-I) characteristics of such arc devices. Stable V-I characteristics of such electric arc devices are obtained by controlling the rate of gas flow through each electric arc device as a function of the arc current. The rate of gas flow through each arc is controlled by deriving for each such arc a control signal from its arc current and actuating a valve in its gas supply means via feedback circuit means to cause the gas flowing there through to vary as a linear function of its arc current.

Device for producing stimulated infrared emission an iraser by means of an electric discharge in a gas mixture which consists partly of carbon dioxide and discharge tube for such a device

Abstract: The invention relates to a device for producing stimulated infrared emission, an iraser, by means of an electric discharge in a gas mixture which mainly consists of carbon dioxide, nitrogen, helium and water vapour and in which the gas mixture is in contact with a quantity of zeolite which is partly saturated with water. The invention furthermore relates to an electric discharge tube for such a device.