RU2348086C1 - Injector of electron with output of electron beam into overpressure medium and electron-beam unit on its basis - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: group of inventions is related to electronics, in particular, to devices intended for electron-beam treatment, welding and beam plasmachemical modification of structural materials in medium at the pressure in working chamber from 10² Pa to 10^-2 Pa. Injector of electrons stipulates for vacuum body structure that comprises differential pumping system (DPS) on axis of transient-time channel with possibility of sliding, and this system is separated into short sections by hollow conic diaphragms, which will make it possible to reduce length of electron beam transportation path, to provide efficient pumping of electron gun volumes and DPS sections, to eliminate possibility of electron beam control system screening and effect of induced magnetic field at control magnetic field. Selection of location place for the first diaphragm installed along direction of electron beam motion and selection of hole size in its smaller base makes it possible to reduce effect of ion flow at units of electron gun. The mentioned altogether will make it possible to increase useful capacity of electron beam, to provide reliable operation of electron beam and injector as a whole, to provide efficient and reliable control of beam. Structural features of working chamber of electron-beam unit in combination with suggested injector will make it possible to expand functional resources of unit due to application of beam energy for heating, excitation and maintenance of different types of discharge in medium with simultaneous application of scattered electrons in technological processes, and also to provide reliable operation of devices due to possibility to perform control and regulation of electron beam parameters and technological parameters in working chamber.

EFFECT: increased useful capacity of electron beam, provision of reliable operation of electron gun and injector as a whole, provision of efficient and reliable operation of beam.

2 cl, 1 dwg

Description

The proposed group of inventions relates to electronics, in particular to devices intended for electron beam processing, welding and plasma beam-chemical modification of structural materials in a gas medium and metal vapor at a pressure in the working chamber from 10 ² Pa to 10 ^-2 Pa.

Known electron injector included in the composition of the electron beam installation (RF patent No. 2192687, IPC: H01J 37/30; C23C 14/30; B23K 15/00, from 11.29.2000, published on 10.11.2002 Bull. No. 31, FIG. 1, [1]) and comprising a vacuum housing in which the triode electron gun installed in the end face, the electron beam transport section and the focusing magnetic lens forming the electron beam emerging from the vacuum housing with the external and internal bipolar tips and external magnetic circuit. In the beam transport section (beam path), an alignment magnetic lens, a grounded cutting diaphragm, a stigmator and sensors for monitoring the beam current and position are installed along its axis.

The disadvantage of the injector [1] is that in the section for transporting the electron beam, which simultaneously performs the function of the first section of the differential pumping system and has a length significantly greater than its diameter, the passage channel has a variable cross section. In the area of the cutting diaphragm, the section of the passage channel is equal to the section of the electron beam. In sections of the section from the cutting diaphragm to the end face of the anode flange of the triode gun on one side and to the surface of the hollow conical pole tip of the focusing magnetic lens on its other side, the section of the passage channel is equal to the mid-section of the hole of the corresponding functional device. In this regard, at the average pressure established in this region, the gas coming from the side of the focusing magnetic lens moves towards the electron beam in a variable from molecular to molecular-viscous mode, and the likelihood of shock waves (Mach disks) is not excluded. In a passage channel of variable cross section, shock waves expanding in the radial direction are repeatedly reflected from the walls and can form hybrid waves and pressure zones. In addition, due to the dense packing of the section by structural elements with a developed external surface, it is difficult to ensure proper gas pumping from the area of the electron-optical gun system and from the electron beam transport section.

When an electron beam is exposed to a gas whose pressure at the leading edge of the shock wave can significantly exceed the average pressure, the energy of the beam for heating and ionizing the gas increases, the flux of ions bombarding the cathode increases, and its service life is reduced. At the same time, the temperature of the nearby walls of the section rises, the emission of harmful gases, for example carbon-containing, which enter the electron gun through the anode, increases. At the same time, chemical compounds are formed on the heated cathode, which reduce the emission characteristics of the cathode, and on the cold walls of the gun, the gas condenses in the form of a conductive coating, which reduces the electrical strength of the insulation. In addition, there may be pairs of soft magnetic materials in the gas that condense on the walls of the section and shield the electromagnetic fields created by magnetic lenses. As a result, the life of the cathode of the electron gun is reduced, the dielectric strength is insulated, the configuration of magnetic fields is distorted, and overall the efficiency and reliability of the injector [1] are reduced. Another disadvantage of the injector [1] is that an alignment magnetic lens, a stigmator, and a focusing magnetic lens placed sequentially along the axis of the electron beam transport section, which correct the geometric dimensions of the beam cross section, do not allow scanning, deflection, and dynamic focusing of the electron beam. In this regard, it is impossible to expand the limits of regulation of the specific energy parameters of the injector [1], for example, power density or radiation dose, which limits its functionality and narrows the scope of application in technology.

Known electron injector, which is used in electron beam installations (RF patent No. 2296038, IPC: B23K 15/06; H01J 37/315, 04/15/2005, published on 03/27/2007 Bull. No. 9, FIG. 1 and 2, [2]) and contains: a triode electron gun, the anode flange of which is made in the form of a cylindrical glass; an electron beam transportation system, which is made in the form of a beam guide body interfaced with a cylindrical glass of the anode flange; system of autonomous pumping devices. At the same time, a centering magnetic lens is installed in the cavity of the cylindrical glass of the anode flange between the conical diaphragms, which is separated by a disk partition with one of the conical diaphragms mounted on it from magnetic focusing and deflection lenses installed in the beam casing. The cavity of the triode electron gun and the cavity of the cylindrical glass of the anode flange bounded at the ends by conical diaphragms with the function of the first section of the differential pumping system communicate through the corresponding pump nozzles with autonomous pumping devices.

The disadvantage of the injector [2] is that the electron beam transport path, which includes a portion of the cylindrical cup of the anode flange and the beam path limited by conical diaphragms, has a large length. In the area where the magnetic focusing lenses and the deflection of the electron beam are located, the pressure is much higher than in the electron gun, and the induction of the magnetic field created by the focusing system first increases to a maximum, then decreases and then changes according to the algorithm specified by the deflection system. Under the influence of an electron beam on a gas of high pressure, the process of gas ionization is intensified in the field of action of magnetic fields, and the development of a beam-plasma discharge and the generation of microwave energy are not ruled out. As a result, the injector operation is destabilized [2]. Due to the energy loss of the beam for heating and ionization of the gas, its efficiency decreases. The flow of ions bombarding the cathode increases, while the thermal stress of the structure increases, the cathode life and electrical insulation strength decrease. In addition, in the injector [2] there is no possibility of cleaning the inner surfaces of the beam from the condensate that shields the magnetic fields of the lenses. As a result, the reliability of the injector [2]. In addition, the disadvantage is that magnetic lenses contain a large amount of gas and do not undergo high-temperature degassing treatment. In this regard, it is highly probable that harmful gases, such as carbon-containing gases, that enter the electron gun are released, poison the cathode and reduce the dielectric strength, and as a result, the reliability of the injector [2] and the electron-beam unit using it as a whole decreases.

A known injector for outputting an electron beam into the atmosphere (RF patent No. 967251, IPC: H01H 5/02; H01J 29/48, dated 11/12/1980, published on 03/27/1996, Bull. No. 9 (II hours), [3]), comprising: an electron gun; a beam guide, which is mounted on the anode flange and consists of a telescopic sleeve sealed with a bellows and carrying a focusing and deflecting coil, and lock chambers formed by plates with built-in additional lenses for electromagnetic beam transport and separated by conical diaphragms; gas-dynamic shutter at the device output. In this case, the beam path and the lock chambers perform the functions of sections of the differential pumping system (LPS), separated by conical diaphragms. An individual vacuum pumps are connected to the beam guide and lock chambers through the pumping (transitional) pipes.

The disadvantage of the injector [3] is that in the beam guide and in the lock chambers that form the differential pumping system in the form of sections located along the axis and separated by conical diaphragms, each of which is covered by a magnetic lens, the possibility of a beam-plasma discharge is not excluded. This is due to the fact that in the injector [3] the indicated pressure drop between neighboring sections is more critical and the gas coming from the gas-dynamic shutter moves with supersonic speed towards the electron beam. At the same time, at the exit of each conical diaphragm, the gas stream has the configuration of a gas-dynamic “barrel” with disk-shaped zones of increased pressure (Mach disks). With the simultaneous action of an electric field created by an electron beam and a longitudinal magnetic field created by magnetic lenses distributed along the axis, gas ionization is intensified, plasma is formed and microwave waves are excited, the amplitude and frequency of which depend on the power of electromagnetic fields and gas pressure. As a result, the energy loss of the electron beam, the ion flux bombarding the cathode, and the temperature of the device increase, but overall the efficiency and reliability are reduced.

In addition, the disadvantage is that in the injector [3] the device for electromagnetic beam transport does not allow sweep and deflection of the electron beam and, as a result, it is impossible to extend the limits of regulation of the specific energy parameters of the injector [3], for example, power density or radiation dose. In addition, there is no possibility of cleaning the walls of the SDO from condensate, the screening field of magnetic lenses. In this regard, the injector [3] has limited functionality and scope in technology.

In addition, an electron injector is known for introducing a beam into the atmosphere (RF patent No. 1098513, IPC: Н05Н 5/00; H01J 29/48, dated January 11, 1982, published March 27, 1996, Bull. No. 9 (II hour .), [4]), comprising: an electron gun; a device for conducting a beam (beam path), which is mounted on the anode flange and is equipped with control magnetic lenses; a gas-dynamic path made in the form of a parallelepiped, into the central cylindrical channel of which removable conical diaphragms are built and divide it into sections; gas-dynamic shutter, which is installed at the outlet of the injector. The gas-dynamic tract sections are connected to individual vacuum pumps by means of holes in the diaphragms and adapters on its side faces.

The disadvantage of the injector [4] is that the beam path with control magnetic lenses, i.e. the first section of the differential pumping system from the anode of the electron gun to the first conical diaphragm of the gas-dynamic path has a length significantly greater than the length of the gas-dynamic “barrel”. In this section, several zones of wave-like gas movement are formed. The gas pressure at the leading edge of each wave significantly exceeds the average pressure in the considered section. At the pressure drop indicated in [4], the molecular-viscous regime of gas motion, which moves at a supersonic speed towards an electron beam with periodic shock waves, cannot be ruled out. When an electron beam acts on a gas, especially in high pressure zones, the energy losses of the beam on heating and ionization of the gas increase, and the flux of ions bombarding the cathode increases. At the same time, thermal stress and gas desorption increase. Chemical compounds are formed on the heated cathode, which reduce its emission characteristics. On the cold walls of the gun, some condensing gases, for example carbon-containing, are deposited in the form of a conductive coating, which reduces the dielectric strength. In addition, there may be pairs of soft magnetic materials in the gas that condense on the walls of the beam path and shield the field of magnetic lenses. As a result, the efficiency and reliability of the injector are reduced [4].

In addition, the disadvantage of the injector [4] is that the device for electromagnetic beam transportation does not allow sweep, deflection, and dynamic focusing of the electron beam and, as a result, it is impossible to extend the control limits of the specific energy parameters of the injector, for example, power density or radiation dose, which limits its functionality and narrows the scope in technology.

The closest in technical essence and selected as a prototype is an electron injector with the output of the beam into the gaseous medium (RF patent No. 1340567, IPC: Н05Н 7/00; H01J 29/48, dated 02.01.1986, publ. 05/10/1996 g Bulletin No. 13, [5]), which contains: a vacuum chamber equipped with a pumping nozzle; a triode electron gun placed in a vacuum chamber; a cylindrical hollow beam guide connected to the anode flange of the electron gun; differential pumping system with conical diaphragms; gas-dynamic shutter at the device output. At least one magnetic lens is placed on the beam guide. In this case, the SDO is located in the beam guide, and the cavity between the SDO case and the beam guide is divided by partitions into sectors connected via individual adapters to individual vacuum pumps.

The disadvantage of the injector [5] is that, in the beam guide, from the anode of the electron gun to the larger base of the first conical diaphragm of the SDO, the span electron channel is located in the region of a weak magnetic field created by at least one magnetic lens. Moreover, the pressure on this first section is, as a rule, an order of magnitude higher than in the electron gun. In the second section, i.e. in the LMS, located between the smaller base of the first conical diaphragm and the large base of the second conical diaphragm, the span channel of the electrons is located where the magnetic induction reaches its maximum. Moreover, the pressure in this area, as a rule, is two orders of magnitude greater than in the electron gun. In the third section of the beam guide, the transit electron channel is located in the region of a decreasing magnetic field. Moreover, the pressure in this third section is higher than in the second. At the pressure differences indicated in [5], in the adjacent sections of the SDO, the gas coming from the gas-dynamic shutter moves toward the electron beam at a supersonic speed, and at the exit of each conical diaphragm of the SDO, the gas flow forms a gas-dynamic “barrel”, the virtual bottom of which is formed by a gas layer high pressure - Mach disk. When an electron beam is exposed to a gas, especially in a high-pressure gas layer, in a region of a strong magnetic field, i.e. in the second section of the SDO, the process of gas ionization is intensified, and the development of a beam-plasma discharge and the generation of microwave energy are not ruled out. As a result, the operation of the injector is destabilized [5]. Due to the energy loss of the beam for heating and gas ionization, the efficiency decreases. The flow of ions bombarding the cathode increases, the thermal stress of the structure increases, and the cathode's operating life and dielectric strength decrease. As a result, the reliability of the injector [5].

In addition, the disadvantage of the injector [5] is that to ensure the specified energy parameters of the magnetic lens, which are proportional to the energy of the electron beam and its geometric dimensions, increased power is required. In addition, in the indicated injector, there is no possibility of cleaning the internal surfaces of the beam guide and DLS from condensate, which shields the magnetic lens field. As a result, reliability is reduced.

Another disadvantage is that in the injector [5] the device for electromagnetic beam transportation does not allow sweep, deflection of the electron beam and, as a result, it is impossible to expand the control limits of the specific energy parameters of the described injector, for example, power density or radiation dose, which limits its functionality and narrows the scope of technology.

Known electron beam installation (RF patent No. 2192687, IPC: H01J 37/30; C23C 14/30; B23K 15/00, from 11.29.2000, publ. 10.11.2002 Bull. No. 31, Fig.2 and 3, [6]), comprising: an injector, which is made according to [1] in a vacuum housing with a pump nozzle; a working chamber, which is equipped with a coordinate table and is made with a pump nozzle; differential pumping system. In this case, the input of the working chamber is interfaced with the output of the vacuum housing of the injector through a differential pumping system, which is combined with the working chamber and contains at the inlet an intermediate chamber with an individual pumping nozzle formed by the external part of the working chamber body and the external pole tip of the magnetic lens of the injector.

In addition to the above-mentioned disadvantages of the injector [1] used in the electron-beam installation [6], which affect the efficiency and reliability of the entire installation as a whole, the disadvantage of the installation [6] is also the presence of beam electron losses in the working chamber, because it does not provide for the use of scattered, including reflected, beam electrons. Given that the energy loss of the beam due to heating and ionization of the gas during transportation in high pressure medium and the unused energy of the electrons reflected from the irradiated object exceed 30%, the efficiency of the installation is quite low. In addition, a concentrated electron beam is output through the SDO to the working chamber, the trajectory of which cannot be changed, because In the injector [1] there is no system for deflecting and scanning the beam. In this regard, the possibilities of controlling specific energy parameters (power density or radiation dose) are limited. The disadvantage of the electron-beam installation [6] is also that the design of the working chamber does not allow controlling the output parameters of the beam, regulating the operating conditions of the installation as a whole, letting in the working gas (gas mixture), and effectively using the energy of the electron beam to create plasma in the affected area to the irradiated object and realize plasma-chemical technological processes in the medium of high pressure working gas. As a result, the field of technological application of the electron-beam installation [6] is limited.

The closest in technical essence and selected as a prototype is an electron beam installation (RF patent No. 2296038, IPC: B23K 15/06; H01J 37/315, dated April 15, 2005, published March 27, 2007 Bull. No. 9, FIG. 2, [7]), comprising: an electron injector, which is made according to [2]; vacuum housing (working chamber) with pumping nozzle and coordinate table. In this case, the beam of the injector with focusing and deflecting magnetic lenses is located in the working chamber.

Similarly to the installation [6], the disadvantage of the electron-beam installation [7] is that the design of the working chamber does not provide for the use of scattered, including reflected, beam electrons. Considering that the energy losses of the beam due to heating and ionization of the gas during transportation in high pressure medium, as well as the unused energy of the electrons reflected from the irradiated object, exceed 30%, the efficiency of the installation [7] is low. Considering the above-mentioned disadvantages of the injector [2] and the lack of the ability to let in and regulate the gas pressure in the working chamber, the area of technological application of the installation [7] is quite limited.

The basis of the proposed group of technical solutions is the task of creating designs of the electron injector and the electron beam installation using it, which simultaneously allows:

- reduce the energy loss of the electron beam in the beam of the injector associated with ionization of the gas of the oncoming supersonic stream, which will increase the useful power of the beam extracted into the medium with increased pressure of the working chamber of the installation;

- reduce the flow of ions that bombard the elements of the gun’s EOS, in particular its cathode, and affect the heat stress and shape stability of the EOS;

- to provide the possibility of periodic cleaning of the beam guide in the areas of the focusing systems, sweeps, and deviations from the sawn magnetic conductive coating, screening these systems;

- ensure the efficient use of the energy of secondary electrons in technological processes, including plasmochemical ones, in the control of the parameters of the injector beam, the parameters of the focusing systems, the deflection and sweep of the electron beam and the technological parameters of the installation, as well as their control.

The technical result from the implementation and use of the proposed group of devices is:

- improving the reliability of the injector and the cathode-ray installation as a whole by increasing the cathode resource and the dielectric strength of the electron gun insulation, eliminating the possibility of shielding focusing systems, deflecting and scanning the beam, the ability to control and adjust the parameters of the injector beam and the technological parameters of the cathode-ray installation;

- increasing the efficiency of the injector and the electron beam installation as a whole by reducing the leakage current to the walls of the beam guide, reducing the energy loss of the electron beam for heating and gas ionization during transportation to the SDO, and using scattered (including reflected) beam electrons in the working chamber for monitoring and adjusting the parameters of the injector and the installation as a whole;

- expanding the scope of application of devices due to the simultaneous regulation of the energy parameters of the injector and the installation with a metered supply of gas or gas mixture into the working chamber.

The solution of the problem and the corresponding technical result are achieved by the fact that:

- in the proposed electron injector with the output of the electron beam to a medium with a high pressure, containing a vacuum housing, placed triaxially symmetrically on the axis of the passage channel a triode electron gun with a beam current monitoring sensor, an axially symmetric focusing system, a sweep system and an electron beam deflection, a differential pumping system with diaphragms covering the passage channel made in the form of truncated hollow cones and directed by smaller bases in the direction of motion of the electron beam, and smart shutter, the vacuum housing contains two hollow plates with axial through holes that are interfaced with their cavities, the plates being connected coaxially with a hollow spacer made of non-magnetic material, in which a section in the form of a hollow cylinder is coaxially connected at one end to a section in the form of a hollow cone at its smaller the base, while the spacer with the large base of the section of the hollow cone is vacuum-tightly attached to the first plate, on which an electron gun is mounted from the opposite end of its axial hole, and the other end as a hollow cylinder, to a second plate with a sleeve of non-magnetic material docked at the axial hole of the axial hole to which a vacuum shutter is fixed, in addition, the cavity of the first plate is divided by a partition that encloses the electron gun body along the slip fit, and connected to the corresponding pump nozzles collinear pumping channels, and the cavity of the second plate is divided by a partition, which has a through hole coaxial with the electron gun, connected to the corresponding pumping channels the nozzles are collinear pumping channels, the diameters of the coaxial holes of the spacer cylindrical section, the second plate and sleeve baffle are equal, the electron beam focusing system is fixed to the spacer, and the electron beam sweep and deflection system is fixed to the bushing, while the differential pumping system has short and long hollow cylinders of non-magnetic material, the ends of which are connected to each other by elastic struts, and a long cylinder, the free end of which is firmly pressed against the saddle of the vacuum shutter, with it is slid down (with the possibility of sliding) with holes in the partition of the second hollow plate, the portion of the hollow spacer cylinder and the sleeve, and the free end of the short cylinder is tightly pressed against the anode flange of the triode electron gun on which the electron beam current monitoring sensor is fixed, in addition, the first in the direction of movement of the electron beam diaphragm of the differential pumping system with a large base mounted on a short cylinder, and the second and third diaphragms with large bases fixed in its long cylinder Dre and divide the differential pumping system into sections, while the smaller base of the first diaphragm is located in the crossover region of the electron beam, and the diameter of the hole in it is equal to the diameter of the span channel, while the smaller base of the third diaphragm is located outside the zone of deployment of the sweep system and the deviation of the electron beam from the side electron guns, in addition, in sections of the long hollow cylinder of the differential pumping system, in which the third and second diaphragms are located, radial holes are made in zones with the tension of these sections with the corresponding collinear pumping channels of the second hollow plate, while in the case of the triode electronic gun holes are made in the interface zone with one of the collinear pumping channels of the first hollow plate, and its other collinear pumping channel is associated with a region that is limited along the axis of the span the channel by the anode flange of the triode electron gun and the large base of the second diaphragm of the differential pumping system;

- in an electron-beam installation containing an electron injector with the electron beam output to a medium with high pressure and a working chamber with a pump nozzle, a working gas supply device and a coordinate table coaxial with the electron injector, the electron injector is made according to claim 1, wherein in the working chamber, which is connected at one end to the electron injector from the side of the vacuum shutter, axially symmetric, coaxial with the injector, are placed and provided with corresponding current leads electrons and electrically isolated relative to the working chamber and from each other, a perforated tube with sides at the ends, at least part of which is made of soft magnetic material, disks with axial holes, one of which is located between the perforated tube and the vacuum shutter of the electron injector, and the other disk - between the perforated tube and the coordinate table, a cylindrical cassette that is made of non-magnetic material and covers the perforated tube, a solenoid that is made with a screen made of non-magnetic material and covers a cylindrical cassette with a perforated tube inside and disks, in addition, an electron receiver with a current lead is fixed and electrically isolated from it with a current lead, while the disk between the perforated tube and the vacuum shutter is fixed in its working chamber at its end, which is combined with the end face of the electron injector, and the disk between the perforated tube and the coordinate table, perforated tube, cylindrical cassette, solenoid with an internal screen, coordinate l and the current lead of the electron receiver are fixed in the working chamber on its removable flange of the end face opposite to the electron injector.

The proposed implementation of the structural elements of the vacuum injector body and LMS, which allows you to place LMS elements in the electron beam transport path (beam path), will reduce the length of the beam path, which will reduce the leakage current on its walls. At the same time, the design of the beam path due to the rational choice of its diameter and separation by the diaphragm of the SDO into parts of small length that communicate through collinear pumping channels in the plates of the vacuum casing with pumping pipes acting as receivers will increase the pumping efficiency. Specified in the aggregate will reduce the energy loss of the beam and, therefore, increase its useful power. In addition, since the diameter of the passage channel in the first section of the LMS is determined by the diameter of the hole in the smaller base of the first diaphragm, and the diameter of the electron beam has the smallest cross section in the crossover zone, the proposed location of the smaller base of the first diaphragm and the size of its hole will provide the greatest resistance to the movement of the gas stream from the working chamber of the installation, which will reduce the flow of ions acting on the nodes of the electron gun. The location of the smaller base of the third diaphragm outside the zone of deployment of the sweep system and the deflection of the electron beam, which operates, as a rule, at high frequencies, will reduce the effect of induced magnetic fields in the aperture on the control magnetic field of the sweep and deflection system. And the implementation of the parts of the vacuum housing and LMS from non-magnetic material in the areas of placement of the electron beam control systems and securing the LMS cylinders for sliding fit with the possibility of cleaning from shielding coating control systems will provide effective and reliable control of the beam.

The use of the proposed injector in an electron beam installation while supplying its working chamber with a system of coaxial with the injector, axially symmetric, electrodes isolated from each other and from the working chamber (perforated tube, disks from both of its end sides, cassette), respectively, and placed in a magnetic field placed in the working chamber of the solenoid, will provide the ability to use the energy of scattered, including reflected, electrons in technological processes. At the same time, the presence of a beam current sensor on the flange of the anode of the gun in the injector and disks on both sides of the perforated tube in the working chamber of the installation makes it possible to monitor and control the parameters of the beam and technological parameters in the working chamber, which will ensure reliable operation of the devices. In addition, scattered electrons are used in the process to excite and maintain various types of discharge in a gas or gas mixture, which will expand the functionality of the installation.

Comparison of the claimed group of devices with the prior art in known sources of information allows us to conclude that the proposed group of devices meets the criterion of "novelty."

The claimed group of devices is characterized by a combination of features exhibiting new qualities, which allows us to conclude that the criterion of "inventive step" is met.

The drawing shows a schematic representation of an electron injector with the output of the electron beam in a medium with high pressure and using its electron-beam installation.

The electron injector shown in the drawing is made with a differential pumping system located in the electron beam transport path (beam path) and contains axisymmetric axes on the axis of the passage channel: a triode electron gun 1 with a cathode 2, a control electrode 3 and anode 4, on the flange of which a sensor 5 is mounted electron beam current control; an axially symmetric focusing system 6 of the electron beam, which can be performed with a stigmatator 7; scanning system and deflection of the 8 electron beam; differential pumping system (SDO), made of non-magnetic material and with equal internal diameters D, short 9 and long 10 hollow cylinders, the ends of which are connected to each other by elastic struts 11, and diaphragms 12, 13 and 14, covering the passage channel and made in in the form of truncated hollow cones directed by smaller bases in the direction of motion of the electron beam, in addition, the first diaphragm 12 in the direction of movement of the electron beam is mounted on a short cylinder 9 with a large base, and the second and third diaphragms 13, 14 are secured in the large bases long cylinder 10 and the differential pumping system is divided into sections, wherein the free end of the short cylinder 9 is pressed firmly against the flange 4 to the anode of triode electron gun 1; a vacuum shutter 15, to the seat 16 of which the free end of the long cylinder 10 of the differential pumping system is tightly pressed.

In addition, the electron injector has a vacuum housing, consisting of the first 17 and second 18 plates, which are hollow and with axial through holes associated with their cavities, while the plates 17 and 18 are connected coaxially by a spacer 19, which is made hollow of a non-magnetic material and has sections in the form of a hollow cylinder 20 and a hollow cone 21, coaxially mated with each other on the smaller base of the cone 21, while the spacer 19 with the large base of the cone 21 is vacuum-tightly connected to the plate 17, on which from the opposite end of its axial a triode electron gun 1 is installed in the hole, and the other end of the cylinder 20 is connected to the plate 18 with a sleeve 22 made of non-magnetic material docked at the opposite end of its axial hole; in addition, the cavity of the plate 17 is divided by a partition 23 covering the slide of the electron gun 1 body by sliding collinear pumping channels 24, 25, which are connected to autonomous pumping nozzles 26, 27, and the cavity of the plate 18 is divided by a partition 28 into collinear pumping channels 29, 30, connected to autonomous pumping nozzles 31, 32 respectively venno, wherein the partition plates 28, 18 is coaxial with the electron gun one opening, wherein the diameters of the sleeve openings 22, partition plates 28, 18 and the cylindrical portion 20 of the spacer 19 equal.

United by elastic struts 11, short 9 and long 10, SDO cylinders have equal inner diameters D and are placed in the injector vacuum housing between the flange of the anode 4 of the electron gun 1 and the seat 16 of the vacuum shutter 15, and the long cylinder 10 is mated along a slip fit, i.e. with the possibility of sliding, with holes in the sleeve 22, the partition 28 of the hollow plate 18, a section of the hollow cylinder 20 of the spacer 19.

In this case, the focusing system 6 of the electron beam is fixed on the spacer 19, and the sweep and deflection system 8 of the electron beam is mounted on the sleeve 22.

In the LMS, the smaller base of the first diaphragm 12 is located in the cross section of the electron beam, which coincides with the image plane P _i , and the diameter of the hole in it d ₁ is equal to the diameter of the passage channel d _i in the first section of the LMS. In this case, the location of the larger base of the second diaphragm 13 may coincide with the plane of the object P _about , and the smaller base of the third diaphragm 14 is located outside the area of the scanning system and the deviation 8 of the electron beam from the side of the triode electron gun 1.

In addition, in the sections of the long hollow cylinder 10 of the differential pumping system, in which the second 13 and third 14 diaphragms are placed, radial holes 33, 34 are made in the interface zones of these sections with the corresponding collinear pumping channels 29, 30 of the hollow plate 18. In the case of the triode electronic guns 1 made holes 35 in the interface between it and the collinear pumping channel 24 of the hollow plate 17, while another collinear pumping channel 25 of the plate 17 is paired with an area limited along the axis of the passage channel by the anode 4 electric flange hydrochloric gun 1 and the large base of the second diaphragm 13 DLS.

Presented on the drawing, the electron beam installation contains: the above-described electron injector, which fully complies with claim 1 of the formula; a working chamber 36 with a pumping nozzle 37, a working gas supply device (for example, a leak) 38 and a coordinate table 39 coaxial with the electron injector.

The working chamber 36 is connected at one end to the electron injector from the side of the vacuum shutter 15. In this case, in the working chamber 36 above the coordinate table 39 and coaxially with the passageway of the electron injector, there are axially symmetric electrically isolated from each other and from the working chamber 36: perforated tube 40 s sides at the ends, at least part of which is made of soft magnetic material; disks 41, 42 with axial holes, the disk 41 is located between the perforated tube 40 and the vacuum shutter 15, and the disk 42 is between the perforated tube 40 and the coordinate table 39; a cylindrical cartridge 43 of non-magnetic metal located coaxially with a perforated tube 40; a solenoid 44 with an inner screen 45 of non-magnetic material electrically connected to the working chamber 36, which are located coaxially with the cartridge 43, the perforated tube 40 and cover the disks 41, 42. In addition, an electron receiver 46 with a current lead is fixed and electrically isolated from it 47. The disks 41, 42, the perforated tube 40, the cylindrical cartridge 43 are provided with current leads 48, 49, 50, 51, respectively, and the solenoid 44 has current leads 52 and 53. Moreover, the current leads 48, 49, 50, 51, 52 and 53 are electrically isolated from working chamber 36 and friend about other. The disk 41 is mounted on the end of the working chamber 36 from the side of the vacuum shutter 15. In this case, the disk 42, the perforated tube 40, the cylindrical cassette 43 and the solenoid 44 with the screen 45 are fixed in the working chamber 36 together with the coordinate table 39 and the current lead 47 of the electron receiver 46 on a removable a flange 54 opposite the electron injector end.

Electron beam installation with an electron injector with the output of the electron beam in a medium with high pressure works as follows.

When the installation is turned on and pressures of 10 ⁻¹ Pa are reached in the working chamber 36 and 10 ⁻² Pa in the region of electron beam generation, the cathode 2, the focusing system 6, and the sweep and deflection system 8 of the electron beam are connected to the corresponding power sources (not shown) ) After heating the cathode 2 to a predetermined temperature and connecting the electron gun 1 to a high voltage source (not shown) in the electrostatic electric field between the cathode 2 and the anode 4 of the electron gun 1, a converging electron beam is formed, which is accelerated in the indicated electrostatic electric field and moves along inertia along the axis of the SDO, radially bounded by hollow cylinders 9, 10 with an inner diameter D. In this case, the beam current is measured behind the anode 4 of the electron gun 1 with an integrated current sensor 5. The resulting The information is used to assess the quality of beam formation when it enters the SDO, and also allows you to determine the leakage currents to the electrodes of the electron-optical system of gun 1, evaluate the temperature regime of its operation, and optimize the control algorithm of the electron gun 1.

In the first section of the SDO, upon entering it, the beam passes through the hole in the first diaphragm 12 fixed on the short cylinder 9, the smaller base of which is located in the crossover region of the beam, and then through the hole in the second diaphragm 13. At the same time, the magnetic field is excited by the electron beam when connecting the focusing system 6 and the stigma 7 to the appropriate power sources (not shown).

In the second section of the LMS, the electron beam moves along the section of the passage channel, limited along its axis by the smaller base of the diaphragm 13 and the large base of the diaphragm 14.

In the third section of the LMS, the electron beam moves along the section of the passage channel, which is limited outside the area of the scanning system and the deflection of the electron beam 8 by the smaller base of the diaphragm 14 from the side of the electron gun 1 and the end face of the saddle 16 of the vacuum shutter 15. In this section of the LMS, the electron beam is exposed to magnetic the field excited by connecting the scan system and deviation 8 to a power source (not shown). However, the diaphragm 14 does not shield the control magnetic field.

Next, the electron beam passes through the hole in the saddle 16 of the vacuum shutter 15 into the working chamber 36, from the side of which gas flows towards the electron beam. It is known (B.N. Korolev et al., “Fundamentals of Vacuum Engineering”, Energia Publishing House, Moscow, 1975, p. 329, [8]) that, with a pressure ratio between any two adjacent sections of the SDO exceeding the critical value, gas moves at the speed of sound or more. In this case, the structure and geometric dimensions of the gas stream at the outlet of each diaphragm depend on the degree of off-design n _n of the SDO section, which is determined from the relation:

where: P _n , P _n-1 is the average pressure in any two adjacent sections of the SDO, Pa.

It is also known (“Methodology for calculating the differential pumping system”, Zavyalov MA, Zverev VV, Shapiro AL “Instruments and experimental equipment”, No. 4, 1983, p.162-164, [9]) that the gas pressure in any two adjacent sections of the LMS are interconnected by the ratio:

where: F _n - conductivity of the diaphragm, s / l,

S _n - pumping speed, l / s.

At the same time, in the first section of the SDO with an average pressure P ₁ between the diaphragms 12, 13 and the diameter of the passage channel d _{1, the} gas flow moves in the molecular mode (K.M. Ovsyannikov “Calculation of vacuum systems in foundry”, Mechanical Engineering, Leningrad, 1971, p. .20, [10]) provided: P ₁ · D <15 cm · μm Hg

The diameter D of the holes in the cylinders 9, 10 of the SDO and the distance H ₁ between the smaller base of the diaphragm 12 and the large base of the diaphragm 13 are determined when calculating the structure and configuration of the gas flow from known ones (Abramovich G.P. "Applied gas dynamics", Moscow, Nauka, 1976 , [11]) relations:

where: D _max - the maximum diameter of the gas-dynamic barrel of the Mach configuration, enveloping the disk-shaped shock waves (Mach disks), m;

where: N _i is the distance between two adjacent diaphragms of the SDO, m;

d _i is the diameter of the passage channel of the electrons (the smallest diameter of the hole in the hollow conical diaphragm in the LMS section, m;

M is the Mach number;

k is the adiabatic exponent.

The calculation results show that the inner diameter D of the hollow cylinders 9, 10 of the SDO is approximately equal to D _max (D ~ D _max ), and the distance H ₁ between the diaphragms 12 and 13 of the SDO can vary from 4d ₁ to 5d ₁ .

Effective gas evacuation from the volumes of the electron gun 1 and the first section of the SDO, separated by the first diaphragm 12, is achieved due to the fact that gas is pumped from each volume through the corresponding collinear channels 24 and 25 in the plate 17 of the vacuum casing, which is equipped with pumping nozzles 26 and 27, respectively . The volume of each nozzle 26 and 27 is approximately 20 times larger than the volume of gun 1 and the volume of the first section of the SDO. In this regard, each pipe 26, 27 performs the function of a receiver that smooths out pressure fluctuations in the pumped volumes. This allows you to stabilize the pressure, reduce the likelihood of shock waves (Mach disks) and the intensity of gas ionization when exposed to an electron beam. In this case, the effect of ions on the beam compression decreases, and the electric field between the cathode 2 and anode 4 becomes more uniform and penetrates deeper into the beam drift region. This provides Brillouin equilibrium conditions under which the beam pulsations are smoothed out (IV Alyamovsky “Intensive electron fluxes”, Moscow, 1991, p. 37, [12]). The ions entering the accelerating gap do not significantly affect the emission current of the cathode 2. The intensity of the ion bombardment of the gun electrodes 1 decreases and, as a result, the temperature of the electrodes and insulators decreases, the shape stability of thermally stressed assemblies and the electrical insulation strength increase.

If the value of H ₁ exceeds 5d ₁ , then the formation of shock waves is periodic in nature, the number of waves in the area between the diaphragms 13 and 12 increases. At the leading front of each shock wave, the pressure is much higher than the calculated one, and when an electron beam acts on the dense gas layers in the region where the magnetic field of the focusing system 6 exists, high-frequency beam-plasma oscillations can occur that destabilize the operating mode. When the value of H ₁ less than 4d ₁ there is a premature reflection of the shock waves of the gas stream from the oncoming diaphragm 12 and the formation of hybrid waves of high pressure. The diameter of the gas-dynamic barrel increases, the leakage current of the electron beam to the walls of the SDO increases, and the efficiency decreases. When an electron beam acts on a gas, especially at the leading edge of a shock wave, the formation of gas ions is intensified, which move toward the electron beam and bombard the cathode. As a result, the temperature of the electron-optical system of the gun 1 increases, the shape stability of the electrodes and the dielectric strength of the insulation decrease, and as a result, the reliability decreases.

The parameters obtained by calculation were used to solve the complex problem of the formation of an electron beam and its electromagnetic transportation along the SDO, in which the pressure increases from section to section along the course of the electron beam. In this case, the optimal geometric parameters of the focusing system 6 of the beam were established, in which the distance between the main planes of the object P _o (cathode 2) and the image P _i (electron receiver 46), approximately equal to the width of the gap S between the poles of the focusing system 6, is taken to be equal to the distance H ₁ between the diaphragms 12 and 13, and the diameter of the pole hole D _f of the focusing system 6 is taken to be approximately equal to the diameter D of the hole in the LMS. The parameters S and D _f are basic in determining the energy characteristic of the focusing system 6 of the electron beam, and its focal length f is determined (Z. Schiller et al. “Electron beam technology”, Moscow, E., p. 80, [13]) ratio:

where: aK (S, D _f ) is a parameter characterizing the geometry of the pole pieces of the focusing system;

U is the accelerating voltage. AT;

N · I - magnetomotive force (MDS), A · revolution.

The optimal gap width between the poles of the focusing system 8 S is determined from the well-known (B.E. Bonstedt, MG Markovich "Focusing and beam deflection in electron-beam devices", Moscow, 1967, p. 83-86, [14]) ratios:

In the second section of the LMS with an average pressure P ₂ between the diaphragms 13 and 14 and the diameter of the passage channel d ₂ , which may differ from the diameter of the flight channel of the first section d _{1 of the} LMS, the gas moves towards the beam at a supersonic speed in the visco-molecular mode with the condition:

15 cm · μm Hg <P ₂ · D <500 cm · μm Hg

The pressure difference between the second and third sections of the SDO determines the choice of the length H _{2 of the} second section, which, as you know, ("Methodology for calculating the differential pumping system", Zavyalov MA, Zverev VV, Shapiro AL “Instruments and experimental technique ”, No. 4, 1983, pp. 162-164, [15]) taking into account the conductivity of the diaphragm 14 and the conductivities of the pumping elements 29, 31 connected by means of a radial hole 33 to the indicated section of the SDO, can be selected in the range of 2 up to 3 diameters of the passage channel in the second section (d ₂ ) SDO.

In the third section of the SDO with an average pressure P ₃ between the diaphragm 14 and the saddle 16 of the vacuum shutter 15 and the diameter of the passage channel d ₃ , which may differ from the diameters of the passage channels in the first d ₁ and second d ₂ sections of the SDO, the gas moves towards the beam at a supersonic speed in the viscous regime with the condition: P ₃ · D> 500 cm · μm Hg

The pressure difference between the third section of the SDO and the working chamber 36 according to [15], taking into account the conductivity of the hole in the saddle 16 of the vacuum shutter 15, the conductivities of the pumping elements 30, 32, coupled through a radial hole 34 with the third section of the SDO, determines the length H _{3 of the} third section. In this case, the length value H _{3 of the} third section can be selected in the range from 1.2 to 1.5 diameters of the passage channel in the third section (d ₃ ) of the SDO.

The identical nature of the gas movement in the second and third sections allows us to describe the general patterns of occurrence of pressure fluctuations in the second and third sections of the SDO. When a supersonic gas stream enters the third and then into the second sections of the LMS, the gas expands radially with the formation of a tubular structure of the gas stream. A shock wave arises in the form of a Mach disk of large diameter, which is reflected from the wall of the hollow cylinder 10, converges to its axis and, reflected from the outer surface of the corresponding diaphragms 14 and 13, diverges again in the radial direction. Inside the tubular structure of the gas stream, a rarefaction zone is formed, into which an additional portion of gas is supplied from the working chamber, exciting pressure pulsations. In this case, intensive pumping of the reflected tubular gas flow from the volumes of the second and third sections of the SDO limited by relatively short distances H ₂ and H ₃ and the wall of the long cylinder 10 is carried out respectively through openings 33 and 34 by collinear channels 29 and 30 of the second plate 18 of the vacuum casing, which equipped with pumping nozzles 31 and 32, respectively. Moreover, each pipe 31 and 32 has a volume significantly exceeding the pumped volumes of the second and third sections of the SDO, and performs the function of a receiver. As a result, the pressure pulsations are smoothed out and when the electron beam is exposed to the gas, the energy loss of the electron beam on heating and gas ionization is reduced, the probability of a beam-plasma discharge with characteristic microwave radiation is reduced, and the efficiency and reliability are increased.

The third conical diaphragm 14 is fixed in a long cylinder 10 SDO so that its smaller base is removed at a distance of H ₃ from the end surface of the vacuum shutter 15, in which a hole is made with a diameter of at least the diameter of the passage channel. In this case, the diaphragm 14 does not shield the control magnetic field of the scanning system and the deflection 8 of the electron beam, since its smaller base is located outside the zone of the scanning system and the deflection 8 of the electron beam from the side of the electron gun 1.

In addition, the performance of the SDO in the form of a removable assembly containing short 9 and long 10 hollow cylinders 11 connected with elastic struts with integrated diaphragms 12, 13 and 14, and the slip mating with the vacuum housing, allows the dismantling of the SDO to clean from magnetic screening contaminants the field created by the focusing system 6, 7 and the system of scanning and deflection 8 of the electron beam, and then re-install LMS with high accuracy.

When using the proposed injector in the electron beam installation shown in the drawing, the electron beam from the injector moves under the influence of magnetic fields of the focusing system 6, 7 and the scanning system and deflection 8 of the beam through the hole in the saddle 16 of the vacuum shutter 15 and through the perforated tube 40 with sides at the ends to the electron receiver 46, which in this device is made in the form of a cone. Other embodiments of the electron receiver 46 are possible, for example, instead of the electron receiver 46 in the form of a cone, another object can be installed on the coordinate table 39, on the surface of which it is necessary to influence the electron beam. The object of irradiation may be the surface of the part, the surface of the substance being modified in the crucible, the collector-energy recuperator, etc.

When the electron beam moves along the perforated tube 40 in a medium with increased pressure, its energy is spent on heating the working gas, which is supplied to the working chamber 39 through the gas leak 38, on heating the surface of the electron receiver 46 and, under certain conditions, on the excitation and development of the beam plasma discharge. Part of the beam energy is scattered on the walls of the perforated tube 40, and part is reflected from the irradiated surface of the electron receiver 46.

When connecting the electron receiver 46, the perforated tube 40 and the disk 42 located above the coordinate table 39 to the corresponding measuring instruments (not shown), the distribution of the beam currents and the fraction of the energy of the scattered, including reflected, electrons are determined. Comparing the obtained values of currents with the readings of the current sensor 5 of the beam mounted on the flange of the anode 4 of the electron gun 1, the parameters of all units of the installation are regulated.

When connecting the perforated tube 40 to the negative pole of the power source (not shown), grounding the disks 41 and 42, electrically isolated from the perforated tube 40, and creating a predetermined pressure by the gas inlet into the working chamber 36, a beam-plasma discharge (SPD) is excited under the influence of an electron beam , in which the dissociation of gas molecules and their deposition on the inner surface of the perforated tube 40.

When connecting the perforated tube 40 to the negative, and the disks 41, 42 to the positive poles of the corresponding power sources (not shown), grounding the electron receiver 46 and the cassette 43 and turning on the solenoid 44 covering the electrode system (perforated tube 40, disks 41 and 42, the cassette 43 and an electron receiver 46), a Penning gas discharge is excited and supported by an electron beam. The contour of a beam moving in a magnetic field is a wavy line with amplitude and spatial period, depending on the electron energy and the magnitude of the magnetic field induction. Moreover, most of the beam energy is converted on the surface of the electron receiver 46 into thermal energy and can be used to heat its surface to predetermined temperatures, up to evaporation. Due to the inhomogeneity of the electric field between the perforated tube 40 and the disks 41, 42, which respectively perform the functions of the cathode and anode of the magnetron, and the inhomogeneity of the magnetic field, especially in the gaps between the ends of the perforated tube 40 and the closely spaced surfaces of the disks 41 and 42, the gas discharge plasma is concentrated directly near the sprayed the surface of the electron receiver 46. As a result of this, there is a centrifugal and gradient motion in the plasma, intensified by the effect of those transmitted through the perforation tion of the tube 40 and the reflected beam 46 from the electron receiver surface. To change the configuration of the magnetic field, it is possible to use a perforated tube 40 consisting of at least two parts made of non-magnetic and soft magnetic material that shields the magnetic field of the solenoid 44. In the general case, the plasma takes a shape close to toroidal, and the densest plasma is formed in the zone spraying the material of the electron receiver 46 in the form of a cone or other irradiation object. As a result of the plasma-chemical reaction, a composite is formed, which is deposited on the inner cylindrical surface of the cassette 43, on which the modified samples are mounted.

Thus, the technological capabilities of the facility are expanded while increasing the efficiency due to the use of scattered beam electrons, including those reflected from the electron cone made in the form of a receiver 46 in the process of exciting and maintaining a gas discharge plasma.

Claims (2)

1. An electron injector with the output of an electron beam to a medium with increased pressure, containing a vacuum housing, a triode electron gun with an axial-symmetric focusing system, an electron beam sweep and deflection system, a differential pumping system with diaphragms covering the passage channel made in the form of truncated hollow cones and directed by smaller bases in the direction of movement of the electron beam, and a vacuum shutter, characterized in that the vacuum housing contains two hollow plates with axial through holes that are interfaced with their cavities, the plates being connected coaxially with a hollow spacer made of non-magnetic material, in which a section in the form of a hollow cylinder is coaxially connected with one end in the form of a hollow cone along smaller base, while the spacer with the large base of the hollow cone section is vacuum-tightly attached to the first plate, on which a triode electron gun is installed from the opposite end of its axial hole, and by the end of the section of the hollow cylinder — to the second plate with a sleeve of non-magnetic material docked at the axial hole of the axial hole to which a vacuum shutter is fixed, in addition, the cavity of the first plate is divided by a partition that encloses the body of the triode electron gun by sliding fit corresponding pumping nozzles collinear pumping channels, and the cavity of the second plate is divided by a partition, which has a through hole coaxial with the triode electron gun, is connected collinear pumping channels with corresponding pumping nozzles, the diameters of the coaxial holes of the spacer cylindrical section, the walls of the second plate and the sleeve being equal, the electron beam focusing system fixed to the spacer, and the electron beam sweep and deflection system fixed, while the differential pumping system has a short and a long hollow cylinder of non-magnetic material, the ends of which are connected to each other by elastic struts, and a long cylinder, the free end of which is tight at at the seat of the vacuum shutter, it is mated to fit the holes with the holes in the partition of the second hollow plate, the portion of the hollow spacer cylinder and the sleeve, and the free end of the short cylinder is tightly pressed against the anode flange of the triode electron gun, on which the electron beam current monitoring sensor is fixed, in addition , the first in the direction of movement of the electron beam diaphragm of the differential pumping system with a large base mounted on a short cylinder, and the second and third diaphragms with large bases fixed in its long cylinder and divide the differential pumping system into sections, while the smaller base of the first diaphragm is located in the crossover region of the electron beam, and the diameter of the hole in it is equal to the diameter of the passage channel, while the smaller base of the third diaphragm is located outside the zone of deployment of the sweep system and the electron beam is deflected from the side of a triode electron gun, in addition, on sections of a long hollow cylinder of the differential pumping system in which the third and second diaphragms are located, radial holes are made there are holes in the interface zones of these sections with the corresponding collinear pumping channels of the second hollow plate, while in the case of the triode electron gun there are holes in the zone of pairing it with one of the colinear pumping channels of the first hollow plate, and its other collinear pumping channel is paired with an area that is limited along the axis of the passage channel, the anode flange of the triode electron gun and the large base of the second diaphragm of the differential pumping system. 2. An electron beam apparatus comprising an electron injector with an electron beam output to a medium with increased pressure and a working chamber with a pump nozzle, a working gas supply device and a coordinate table coaxial with the electron injector, characterized in that the electron injector is made according to claim 1, at the same time, in the working chamber, which is connected at one end to the electron injector from the side of the vacuum shutter, axially symmetric, coaxial with the injector, are placed and provided with corresponding current leads electrons and electrically isolated relative to the working chamber and from each other, a perforated tube with sides at the ends, at least part of which is made of soft magnetic material, disks with axial holes, one of which is located between the perforated tube and the vacuum shutter of the electron injector, and the other disk - between the perforated tube and the coordinate table, a cylindrical cassette that is made of non-magnetic material and covers the perforated tube, a solenoid that is made with a screen made of non-magnetic material and covers a cylindrical cassette with a perforated tube inside and disks, in addition, an electron receiver with a current lead is fixed and electrically isolated from it with a current lead, while the disk between the perforated tube and the vacuum shutter is fixed in its working chamber at its end, which is combined with the end face of the electron injector, and the disk between the perforated tube and the coordinate table, perforated tube, cylindrical cassette, solenoid with an internal screen, coordinate l and the current lead of the electron receiver are fixed in the working chamber on its removable flange of the end face opposite to the electron injector.