SU303738A1 - GAS-DISCHARGE ELECTRON RING HEATER - Google Patents

Description

The known gas-discharge electronic ring heaters of metal bodies of a symmetric shape with a hollow cathode are not reliable enough in operation, have a short service life and a rather complicated structure.

A distinctive feature of the described heater is that it is provided with an annular source of a magnetic field, for example, a solenoid located in the inner cavity of the annular cathode of the coaxial with it and with the heated body, and the cathode consists of two sections, one of which is Radial Section C. -shaped magnetic conductor, part of which is open on the side of the heated body, the other, made of electrically conductive non-magnetic material, is adjacent to the poles of the magnetic circuit from the side, to a magnetic field source, with an electrically conductive magnetic and vacuum-tight contact.

These differences make it possible to increase the reliability of operation, the service life and simplify the design of the heater.

electrode 3. Anode 4 is subject to heating.

The 1 N cylinder flange 2 is made of a ferromagnetic material and is made

at the same time the role of the magnetic conductor and the vacuum shell of the heater. The cylindrical ring (electrode) 3, manufactured by a non-magnetic material, performs the role of a vacuum heater sheath and is connected to the cylinder (and the flange 2) vacuum-tightly by soldering or welding to ensure good sealing and electrical contact.

Flange 5 and stud 6 (multiple studs)

are magnetic conductors and are made of ferromagnetic material.

A heated part (anode 4) is placed along the axis of the heater. The annular cavity bounded by cylinder 1, flange 2 and cylindrical electrode 3 having electrical contact with each other, when the heater is in operation, acts as a negative electrode (hollow cathode).

Voltage is applied between the annular cavity (cylinder 1, flange 2, cylindrical ring of electrode 5) and heated part (anode) 4, (plus to heated part 4. When the heater is in operation, the heated part 4 is a collector electrically passing current through it creates a magical field which, using studs 6, flanges 5 and 2, and a cylinder / is concentrated in an annular loop. The electromagnetic coil 7 is fixed so as to provide on one side the necessary electrical insulation between the coil 7 and the surrounding its parts, and on the other hand to provide air enough to cool the flange 2, the cylindrical ring of the electrode 3 and the cylinder /.

The principle of operation of the heater is as follows.

When the required vacuum is reached inside the heater by means of an electromagnetic coil 7, a magnetic field is created in the volume of the annular cavity, and an attachment is applied between the annular cavity and the heated part. There is a discharge between the surface of the annular cavity and the heated part. The magnetic field, distorting the trajectories of electrons on the one hand, facilitates the elevation of the discharge, and on the other hand, increases the degree of gas ionization in the volume of the annular cavity, so that the discharge is localized in the annular CAVITY. Electrons. Under the action of an electric ion, they acquire kinetic energy and, having reached the anode (the heated part 4, causes its heating.

The operation mode of the heater varies by changing the discharge parameters (current and discharge voltage, gas pressure, magnetic field strength).

The devices and devices necessary to ensure the operation of the heater (vacuum chamber, holder of the heated part, etc.) are connected on the side of flanges 2 and 5.

In case of difficulties with applying voltage to the coil 7, associated with the need to isolate it from the magnetostrictor to the full operating voltage, permanent magnets can be used to create the necessary magnetic ground. This essentially simplifies the feeding circuit of the heater and facilitates its operation.

In the proposed heater, a gas discharge plasma arising in the discharge between the heating object, which is the anode, and the hollow ring cathode placed in a magnetic field is used as the electron source. The presence of a magnetic field in the ring hollow cathode contributes to the plasma concentration in the cathode region due to the fact that under the influence of the magnetic field electrons

move along complex cyclic trajectories and produce a large number of ionizing collisions and only after that do they go to the anode. Under the action of an electric field between the anode and the cathode, the electrons are accelerated to the energies necessary to heat the anode. The use in a ring heater as a source of electrons for a gas discharge hollow ring cathode, which is placed in a magnetic field of a permanent magnet or electromagnet, is new.

By using a gas discharge hollow cathode, the reliability of the heater is significantly increased. Such a cathode is not sensitive to vacuum and is not afraid of ion bombardment, which allows it to operate under relatively poor vacuum. It has a simple design and does not require heat. The heater will operate both at alternating and constant voltage. The absence of initial circuits allows the natrevatel to be supplied directly from the rectifier, if it is necessary to carry out heating at a constant current, and

if it is possible to conduct heating at a variable voltage, then the heater is supplied with voltage directly from the step-up transformer.

The indicated advantages of gas discharge

ring heater indicate its prospects. With a pressure of 5 10 mm Hg. Art. 150 mA anode current was obtained at a voltage of 500 V.

Subject invention

The gas-discharge electronic ring heater of metal bodies of symmetric shape; we, being an anode, contain a hollow cathode, characterized in that, in order to increase reliability of operation, service life and simplify the design of CI1, it is equipped with an annular source magnetic field, for example, a solenoid located in the inner cavity of said cathode coaxially with it and with the heated body, and the cathode consists of two sections, one of which is a C-shaped magnetic conductor in the radial section, the open part of which

located on the side of the heated body, the other, made of electrically conductive non-magnetic material, is adjacent to the poles of the magnetic circuit on the side facing the source of the magnetic field, forming an electrically reliable and vacuum-tight contact with the magnetic circuit.

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