RU2519657C2 - Apparatus for exciting spatial charge in dense gases - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to quantum electronics and can be used to excite active media of gas lasers. The apparatus for exciting spatial charge in dense gases includes a high-voltage source connected to elongated, blade-shaped corona and current-collecting electrodes mounted along a dielectric cylinder which is capable of rotating. An electroconductive screen and a dielectric film are placed on the outer surface of the cylinder, wherein the corona electrode is placed along the radius of the cylinder with spacing from the cylinder. The screen is in form of two or more sections extending along the cylinder and electrically insulated from each other, wherein the section passing through the zone of the blade-shaped corona electrode is connected by a sliding contact to the grounded terminal of the source, and the section pass through the zone of the blade-shaped current-conducting electrode is connected by a sliding contact to the potential terminal of the source. Potential applied to a section of the screen can be controlled, for example, by a potentiometer.

EFFECT: increasing discharge power.

2 dwg

Description

The invention relates to quantum electronics and can be used to excite active media of high-pressure gas lasers. In addition, it can be in demand in electrical engineering and in those areas of technology where extended corona discharge regions are used.

A device is known, an electrostatic generator containing an electric charge conveyor, including a carrier dielectric (tape) with electrodes fixed across its length, drive and driven shafts, a charging and current collection device [1], which uses a similar method of moving charges. The disadvantage of this device is the presence of two shafts in the structure, leading to its complexity, increasing the size of the device and reducing the reliability of operation.

A device is known, adopted as a prototype, comprising a rotating hollow dielectric cylinder with a screen and a metallized dielectric film, along which a knife-shaped corona and collector electrodes connected to a high voltage source are installed with some clearance, patent MKI No. 2030046 H01S, 3/0977 [2 ]. A stable volume discharge is formed in the zone of the knife-shaped corona electrode in a gas atmosphere of atmospheric pressure, the current value of which is limited by the speed of the dielectric V, the surface density of the applied charges and the length of the knife-shaped corona electrode. For fixed dimensions: the radius of the rotor R and the length of the corona electrode of the knife shape, the discharge power is determined by the angular velocity of rotation of the rotor ω, because V = ωR, and the capacity of the dielectric film.

Charges are adsorbed on the surface of the dielectric film and transported to a knife-shaped current collector electrode in the device due to the appearance of an induced field in the dielectric due to its polarization by the electric field in the system: the knife-shaped corona electrode is a screen (the latter acts as an auxiliary electrode). Upon termination of the external field, the dielectric after a certain time interval (τ _p. - relaxation time) returns to its original state. For dipole polarization, this time can reach ~ ^10–2 sec [3]. During this time, a field exists in the dielectric that holds charges on the surface. This fact imposes certain restrictions on the value of the permissible rotation speed of the rotor of the prototype device, and therefore, limits the possibility of increasing the discharge power.

As the disadvantages of the known device, you can specify the following:

,- the inability to ensure complete runoff of surface charges on the collector electrode of a knife-shaped shape during rotation with an angular velocity above a critical value:

,

where L is the length of the arc between the corona and collector electrodes of the knife shape; due to the presence of a residual induced field in the dielectric layer during the passage of the knife-shaped electrode collector zone. This leads to losses in discharge power;

- reducing the efficiency of the process of deposition of space charges on the film in the combustion zone of the corona discharge, due to the presence of residual charges on its surface at a rotor speed above the following value:

.

.

The latter factor leads to a periodic breakdown of the stable combustion regime, since an excess space charge is accumulated in the corona discharge zone.

The technical result to which the invention is directed is to create a device that provides an increase in the power of a continuous volumetric gas discharge in dense media over the entire range of structurally permissible rotor speeds.

The specified technical result is achieved in that in a device containing a high voltage source connected to elongated knife-shaped corona and collector electrodes mounted along a dielectric cylinder configured to rotate, on the outer surface of which there is an electrically conductive screen and a dielectric film, the screen is made in the form several sections extended along the cylinder, electrically isolated from each other.

Moreover, individual sections of the screen in certain positions by means of sliding contacts are included in the electrical circuit of the voltage source. The screen section passing in the process of rotation of the area of the knife-shaped corona electrode is connected to the grounded pole of the source, and the screen section passing the zone of the knife-shaped electrode is connected to the potential pole of the source.

In this case, the potential value on the screen section is regulated, for example, by a potentiometer, etc. This allows you to optimize the magnitude of the field strength in the area of the collector electrode of the knife-shaped shape for the effective draining of surface charges.

The invention is illustrated by two illustrations, in which Fig. 1 shows a diagram of a device: section A-A (Fig. 2) and an electrical connection diagram, and Fig. 2 is a view along B (Fig. 1).

The device consists of a high voltage source 1, a corona electrode 2 of a knife shape, a collector electrode of a knife shape 3 and a cylindrical shell consisting of a dielectric cylinder 4, on the surface of which are located: a screen 5 made of an electrically conductive material, and a dielectric film 6, FIG. 1 . The screen is divided into two or more sections 5, extended along the cylinder, electrically isolated from each other, figure 1, 2. The cylindrical shell is mounted on the shaft of rotation 7, forming a rotor. The inclusion of the screen sections in the electric circuit of the voltage source in the corresponding positions is carried out through the sliding contacts 8, 9 of the roller or other type, by touching the inner surface of the sections protruding relative to the body of the dielectric cylinder. The potential of the section passing the zone of the knife-shaped current collection electrode can be set by the regulator 10, for example, a potentiometer. The number of sections and their width (along the arc) are determined by the design parameters of a particular device, namely: the diameter of the rotor and the location of the collector electrode of the knife shape relative to the corona electrode of the knife shape. The width of the section (the length of the arc of the segment) should be less than the length of the smallest arc connecting the zones of the corona and collector electrodes along the outer surface of the rotor, in addition, the section should not close the sliding contacts. To prevent surface breakdown between the potential screen section and the grounded one, it is advisable to implement such a design that between them there is at least one section without switching to an electric circuit.

The device operates as follows.

When the rotor rotates from the high voltage source 1, a high voltage is applied to the corona electrode of the knife form 2 and the corona discharge is ignited. The pole of the source with zero potential is grounded and connected to the collector electrode of the knife form 3. The section of the screen, which passes the zone of the corona electrode of the knife form, is connected via a sliding contact 8 to the grounded pole. This ensures the development of a corona discharge of the barrier type, and in the dielectric film 6, as a result of polarization, a compensation field is induced, which ensures the adsorption of charges on the film surface. When the charged surface area is moved into the zone of the knife-shaped current collection electrode 3, the corresponding section of the screen first comes off the ground, and then, through a similar sliding contact 9, is connected to the potential pole of the high voltage source. As a result, the dielectric is repolarized. The newly induced field in the layer has the opposite direction and is repulsive in relation to the charges adsorbed on the film surface. In addition, the field in the system: the potential screen is a grounded current collector electrode of a knife shape, is constantly acting and accelerates the movement of charges to the collector electrode of a knife shape, since the ion drift velocity in a gas:

V _al. = K · E,

where K is the mobility of ions;

E is the electric field strength.

Thus, a condition is created for the complete draining of charges on a knife-shaped collector electrode. The potential on the screen can be equal to the potential value on the knife-shaped corona electrode, or be changed by regulator 10 (for example, a potentiometer, etc.) to the optimum value. In the process of further displacement of the dielectric layer, a completely discharged film comes into the discharge region, regardless of the rotation speed. This ensures maximum efficiency of the process of adsorption of spatial charges by the dielectric film of the device. The limiting factor in the growth of discharge power will be only the capacitance of the dielectric layer.

Literature

[one]. Novikov M.T. Electrostatic generator. // Application: 4936018/25 from 1991.05.14. RU (11) 2027298 (13) C1, (51) 6 H02N1 / 08.

[2]. Zhuravlev O.A. Volumetric discharge excitation device in dense gases. // Patent 2030046 MKI H01 S3 / 0977. -4842699 / 25. Bull. No.6 of February 21, 1995

[3]. Physical quantities: Reference. A.P. Babichev, N.A. Grandma’s

A.M. Bratkovsky and others; Under. ed. I.S. Grigoryeva, E.Z. Meilikhova. - M., Energoatomizdat, 1991.

Claims (1)

A device for exciting a volume discharge in dense gases, comprising a high voltage source connected to long knife-shaped corona and collector electrodes mounted along a dielectric cylinder rotatable with an electrically conductive screen and a dielectric film on its outer surface, the corona electrode being installed along the radius cylinder with a clearance relative to the cylinder, characterized in that the screen is made in the form of two or more sections, extended in the role of the cylinder and electrically isolated from each other, while the section passing the zone of the knife-shaped corona electrode is connected by a sliding contact to the grounded source pole, and the section passing the zone of the knife-shaped electrode is connected by the sliding contact to the potential pole of the source, in addition, the potential supplied to the screen section can be adjusted, for example, by a potentiometer.

Images