RU175600U1 - SOURCE OF ELECTRONS - Google Patents

Abstract

The utility model relates to the field of plasma technology. The discharge chamber of the electron source is made in the form of a non-separable cermet assembly, consisting of a high-voltage ceramic insulator with metal cuffs soldered to its end parts and a block of cermet insulators welded through the transition ring to the cuff. An anode with a removable annular permanent magnet and a hollow cathode are welded to the block of insulators. A removable emitter cathode is mounted on the adapter ring and mounted on it with a union flange. The outer part of the cap ring, facing the accelerating electrode, has a rounded shape. The technical result is an increase in the reliability of the device. 1 ill.

Description

Technical field

The utility model relates to the field of plasma technology and can be applied in the development of electron beam devices and used in electron beam technologies and experimental physics.

State of the art

Known electronic source with a plasma emitter (Kornilov S.Yu. Obtaining sharply focused beams in electron guns with a plasma cathode / S.Yu. Kornilov, I.V. Osipov, N.G. Rempe // PTE. - 2009. - No. 3. - S. 104-109), which includes a discharge chamber, consisting of two cathodes and a cylindrical anode placed between them, an accelerating electrode and magnetic focusing coils. One of the cathodes (hollow cathode) is a hollow cylinder, the inner surface of which is working for burning the discharge. In the second cathode (emitter cathode), a channel is made for the release of electrons into the vacuum. The magnetic field in the discharge chamber creates a permanent ring magnet. The hollow and emitter cathodes are made of magnetic steel and are elements of a magnetic circuit. Electron emission occurs through the emission channel into the gap formed by the emitter cathode and the accelerating electrode, between which an accelerating voltage is applied. The electron beam is focused by two magnetic coils mounted on the beam line. The specified source allows to obtain electron beams with energies up to 30 keV.

The disadvantage of this technical solution is the low (up to 30 kV) limiting electron energy.

Known electronic source with a plasma emitter (patent RU No. 159300, publ. 02/10/2016), which includes a discharge chamber consisting of a hollow and emitter cathodes and a cylindrical anode placed between them, an accelerating electrode and a focusing magnetic lens. The hollow cathode is a hollow cylinder. The composite emitter cathode is disk-shaped. The main part of the emitter cathode is made of non-magnetic material, and an insert of ferromagnetic material is placed in the center. The discharge chamber is located in a longitudinal magnetic field, which is created by a ring Sm-Co (samarium-cobalt) magnet. To ensure the exit of electrons from the discharge chamber, a channel is made in the insert.

The disadvantages of the electronic source are the low ultimate electron energy and reduced reliability of the source due to the complex design of the emitter cathode. An insert made of ferromagnetic material in the area of contact with the main part of the emitter cathode due to edge effects leads to a significant concentration of the magnetic field, which increases the likelihood of electrical breakdowns of the high voltage gap of the electronic source.

Utility Model Disclosure

The task to which the claimed utility model is directed is to increase the electrical parameters of the device.

The technical result of the implementation of the utility model is to increase the reliability of the device when working with high (over 30 kV) electron accelerating voltage.

The technical result is achieved by the fact that in the electron source containing the discharge chamber, according to the proposed solution, the discharge chamber is made in the form of a sealed welded cermet unit, consisting of a high-voltage ceramic insulator with metal cuffs soldered to its end parts and a block of cermet insulators welded through an adapter ring to the cuff, while an anode with a removable ring magnet and a hollow cathode are welded to the block of insulators, and a removable emitter to Tod mounted on the adapter ring and is secured thereon compression flange, the outer portion of which facing towards the accelerating electrode has a rounded shape.

The utility model is illustrated in the figure.

The figure shows a General view of the ceramic-metal node in the context.

Utility Model Implementation

The discharge chamber of the electron source is made in the form of a non-separable sealed welded cermet unit. The cermet unit consists of a high-voltage ceramic insulator 1 with metal cuffs 2 and 3 soldered to its end parts and a block of cermet insulators 4, welded through an adapter ring 5 to the cuff 3. Anode 6 with a removable ring magnet 7 and a hollow cathode 8 are welded to the block of insulators 4 A removable emitter cathode 9 is mounted on the adapter ring 5 and secured thereto by a sleeve flange 10. The outer part of the sleeve flange 10, facing the accelerating electrode 11, has a rounded shape to reduce voltage the accelerating electric field and increasing the electric strength of the electron acceleration system.

Device operation

An axially symmetric field is created between the hollow and emitter cathodes 8 and 9 of the removable permanent magnet 7 with an induction on the axis of about 0.1 T. The pressure of the plasma-forming gas in the discharge chamber is approximately 5 примерно10 ^-2 Torr. Such pressure is created by a metered gas inlet with a value of about 10-20 cm ³ atm / h, which is supplied through the channel in the hollow cathode 8 and is pumped out through the channel on the axis of the emitter cathode 9. The discharge burns in continuous mode with a voltage of 350-450 V and a current of 0.1 -1.5 A. The specified range of discharge currents allows you to get an electron beam with a current from units to several hundred milliamps. Electron emission from plasma occurs through an opening in the emitter cathode 9 of the discharge chamber into the region of the accelerating field between this cathode and the grounded high-voltage anode (extractor). The electron beam formed in the accelerating gap is focused by a magnetic field and transported to a vacuum chamber or atmosphere through a special output device.

The claimed task and the technical result are achieved through the use of cermet elements, hermetically welded together, on which the discharge chamber of the electron source is assembled, as well as the use of a ring flange with a rounded shape in the accelerating gap, which allows to reduce the intensity of the accelerating electric field and thereby increase the electric strength of the system acceleration of electrons. In general, it becomes possible to increase the accelerating voltage of an electronic source, and hence the limiting electron energy. In addition, the use of a non-separable cermet assembly in the design of the discharge chamber and an increase in the electric strength of the electron acceleration system make the electronic source more reliable and durable.

Claims (1)

An electron source containing a discharge chamber, characterized in that the discharge chamber is made in the form of a non-separable sealed welded cermet unit, consisting of a high-voltage ceramic insulator with metal cuffs soldered to its end parts and a block of cermet insulators welded through an adapter ring to the cuff, while an anode with a removable ring magnet and a hollow cathode are welded to the block of insulators, and a removable emitter cathode is mounted on the adapter ring and mounted on it an acid flange, the outer part of which is facing the accelerating electrode, has a rounded shape.

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