CN113571394A - Anti-creep electricity sterilization electron gun - Google Patents

Abstract

The invention discloses an anti-creeping sterilization electron gun, which comprises a high-voltage input device and an electron beam output device, wherein the high-voltage input device is connected with the electron beam output device; the electron beam output device comprises a vacuum cavity, a plurality of electrode cores with one ends connected with the high-voltage input device are arranged in the vacuum cavity, the other ends of the electrode cores are connected with an electron beam generating device arranged in the vacuum cavity, and an electron beam outlet is formed in the vacuum cavity; the high-voltage input device and the electron beam output device are isolated by the vacuum flange assembly, the vacuum flange assembly comprises a ceramic disc, the ceramic disc is integrally cylindrical, one end of the ceramic disc is closed, the other end of the ceramic disc is open, the electrode cores penetrate through the closed end of the ceramic disc, and the outer side face of the closed end of the ceramic disc faces the vacuum cavity and is provided with a plurality of annular convex edges which are coaxially arranged. The invention has good anti-creepage effect on the premise of keeping the miniaturization of the electron gun.

Description

Anti-creep electricity sterilization electron gun

Technical Field

The invention relates to the technical field of electron beam sterilization, in particular to an anti-creeping sterilization electron gun.

Background

The electron gun is generally applied to scenes such as inelastic electron scattering, fluorescent screen luminescence oscillography and the like at present, because high-speed electron beams carry huge energy, the possibility is provided for the application of the electron gun in the field of radiation sterilization, compared with the traditional electron beam radiation sterilization disinfection equipment, the electron gun has the advantages of small occupied area, convenience in movement and the like, when the electron gun is used for radiation sterilization, complicated modules such as electron bunching, deflection and the like in the current electron gun can be omitted, but due to the light-weight design of electrons, the problem is that after the electrode core is connected with high voltage, a water streak-like electric arc appears on a flange surface connected with the electrode core from the center to the outer edge and climbs along a transition surface, and the creepage phenomenon can cause the insulation reduction of the flange (generally made of ceramics) for a long time and more serious insulation breakdown and safety accidents, therefore, the size of the flange usually has to be increased to avoid the creepage phenomenon, but the size of the electron gun also increases. Therefore, there is a need to develop an electron gun that can effectively prevent creepage while maintaining a light weight design, so as to solve the problem of applying the electron gun to radiation sterilization.

Disclosure of Invention

The invention aims to provide an anti-creeping sterilization electron gun. The invention has good anti-creepage effect on the premise of keeping the miniaturization of the electron gun.

The technical scheme of the invention is as follows: an anti-creep electric sterilization electron gun comprises a high-voltage input device and an electron beam output device; the electron beam output device comprises a vacuum cavity, a plurality of electrode cores with one ends connected with the high-voltage input device are arranged in the vacuum cavity, the other ends of the electrode cores are connected with an electron beam generating device arranged in the vacuum cavity, and an electron beam outlet is formed in the vacuum cavity; the high-voltage input device and the electron beam output device are isolated by the vacuum flange assembly, the vacuum flange assembly comprises a ceramic disc, the ceramic disc is integrally cylindrical, one end of the ceramic disc is closed, the other end of the ceramic disc is open, the electrode cores penetrate through the closed end of the ceramic disc, and the outer side face of the closed end of the ceramic disc faces the vacuum cavity and is provided with a plurality of annular convex edges which are coaxially arranged.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the side surface of the ceramic disc of the vacuum flange assembly facing the vacuum cavity is provided with the plurality of annular convex edges, so that the surface where the vacuum end electrode core is connected with the ceramic disc presents a section of wavy transition surface, the creepage distance is increased on the basis of not changing the disc diameter of the ceramic disc, the creepage phenomenon is not easy to occur, the operation is safer and more stable, and the service life of the electron gun is longer.

Among the aforementioned anti-creep electricity sterilization electron gun, the vacuum flange subassembly is still including the sealing-in cover of cover at ceramic plate cylinder lateral wall, the sealing-in cover includes annular connecting portion and cylindricality portion of cup jointing, cylindricality portion of cup jointing outside cover has the flange of inserting soon, the one end of inserting the flange soon supports one side of annular connecting portion, the opposite side of annular connecting portion is connected with the ring flange, the edge of ring flange inner circle meets by smooth curved surface transition and with the lateral surface of ceramic plate blind end, and then forms the sealed to the vacuum cavity.

In the anti-creeping sterilization electron gun, a plurality of shielding cylinders are arranged between the electrode cores and the electron beam generating devices, the outer side surfaces of the closed ends of the ceramic discs are provided with annular concave parts, the electrode cores are inserted into the closed ends of the ceramic discs in the concave ring rings, shielding cylinder connecting pieces are connected to the concave parts in a clamped mode, the shielding cylinder connecting pieces are connected with the end portions of the shielding cylinders, and ceramic sleeves are sleeved on the outer sides of the shielding cylinder connecting pieces.

In the above-mentioned anti-creep electric sterilization electron gun, the highest point of the annular rib is higher than any point on the sealing sleeve.

In the above-mentioned anti-creep electric sterilization electron gun, the outer side wall of the ceramic disk is provided with a step at a position opposite to the inner side walls of the sealing sleeve and the annular flange.

In the anti-creep electricity sterilization electron gun, the vacuum cavity includes interconnect's first cavity and second cavity, be equipped with vacuum apparatus interface and vacuum degree detection interface on the first cavity, be equipped with the window on the second cavity.

In the anti-creeping sterilization electron gun, the electron beam generating device comprises a reflection polar plate and a grid plate, the reflection polar plate and the grid plate are spliced into a tubular structure with two open ends, the open positions of the two ends are respectively covered with a reflection polar plate, the two reflection polar plates are respectively connected with a fixing seat through a ceramic column, a discharge rod is fixed between the fixing seats, the potentials of the reflection polar plate and the grid plate are equal and higher than the potential of the discharge rod, and the grid plate is provided with a plurality of beam outlet holes.

In the anti-creeping sterilization electron gun, the positions on the side wall of the vacuum cavity corresponding to the beam outlet holes of the grid plate are provided with electron beam outlet ports, the electron beam outlet ports are connected with an exit window positioned outside the vacuum cavity, the exit window comprises a sealing seat, the sealing seat is outwards connected with a titanium window, the outer side of the titanium window is covered with a titanium film, and the outer side of the titanium film is provided with a pressing plate connected with the titanium window and used for fixing the titanium film.

In the aforesaid anticreep electricity sterilization electron gun, high pressure input device is including the cooling oil tank, cooling oil tank one end is connected with the vacuum flange subassembly, and the other end is connected with the inside socket of inserting the cooling oil tank, the socket is connected with the electrode core through the wire.

Drawings

FIG. 1 is a schematic view of the overall appearance structure of the present invention;

FIG. 2 is a schematic view of the internal structural connections of the present invention;

FIG. 3 is a schematic structural view of an electron beam generating apparatus;

FIG. 4 is a schematic structural view of a vacuum flange assembly;

FIG. 5 is a schematic view of the vacuum flange assembly from another perspective;

FIG. 6 is a front view of the vacuum flange assembly from the perspective of FIG. 4;

FIG. 7 is a cross-sectional view of the internal structure of the vacuum flange assembly of FIG. 6 taken along line A-A;

FIG. 8 is a schematic structural view of a ceramic disk;

fig. 9 is a schematic view of the structure of the exit window;

FIG. 10 is a schematic view of a titanium window construction;

FIG. 11 is an enlarged view of a portion of FIG. 10 at A;

FIG. 12 is an exploded view of the high pressure input device;

FIG. 13 is a schematic view showing a connection structure of a shield cylinder and an electron beam generating apparatus;

FIG. 14 is a schematic diagram showing the uniformity of the beam emitted from the electron gun simulated by the simulation software under the conditions of group 1 in the example;

FIG. 15 is a schematic diagram showing the uniformity of the beam emitted from the electron gun simulated by the simulation software under the conditions of group 2 in the example;

FIG. 16 shows the uniformity of the emitted beam of the electron gun under the conditions of group 1 in the example;

FIG. 17 shows the uniformity of the emitted beam of the electron gun under the conditions of group 2 in the example.

Reference numerals: 1-high voltage input device, 2-electron beam output device, 10-vacuum flange component, 20-shielding cylinder, 21-vacuum cavity, 22-electrode core, 23-electron beam generating device, 24-electron beam outlet, 25-exit window, 30-shielding cylinder connecting piece, 40-ceramic sleeve, 50-sealing seat, 60-titanium window, 70-titanium film, 80-pressing plate, 90-aluminum wire, 100-cooling oil tank, 101-ceramic disk, 102-sealing sleeve, 103-quick-insertion flange, 104-annular flange, 200-socket, 201-cross connecting piece, 211-first cavity, 212-second cavity, 213-cavity supporting base, 231-reflection polar plate, 232-grid plate, 233-reflection polar plate, 234-ceramic column, 235-fixed seat, 236-discharge rod, 237-press block, 501-recess, 601-support bar, 602-flat hole, 603-reinforcing rib, 1001-oil tank body, 1002-oil tank cover, 1003-oil inlet, 1004-oil outlet, 1005-sealing flange, 1006-sheet flange, 1007-rectangular notch, 1011-annular convex edge, 1012-concave, 1013-step, 1021-annular connecting part, 1022-cylindrical sleeve part, 2111-vacuum equipment interface, 2112-vacuum degree detection interface, 2121-window, 2321-beam outlet hole, 2322-bending part and 2331-connecting lug.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

Example (b): an anti-creep electric sterilization electron gun, the structure is shown in fig. 1 to 13, comprising a high voltage input device 1 and an electron beam output device 2; the electron beam output device 2 comprises a vacuum cavity 21, a plurality of electrode cores 22 with one ends connected with the high-voltage input device 1 are arranged in the vacuum cavity 21, the other ends of the electrode cores 22 are connected with an electron beam generating device 23 arranged in the vacuum cavity 21, and an electron beam outlet 24 is arranged on the vacuum cavity 21.

The electron beam generating device 23 includes a reflective plate 231 and a grid plate 232, the reflective plate 231 and the grid plate 232 are spliced into a tubular structure with two open ends, the open ends of the two ends are respectively covered with a reflective plate side plate 233, the two reflective plate side plates 233 are respectively connected with a fixing base 235 through a ceramic column 234, a discharge rod 236 is fixed between the two fixing bases 235, the plurality of electrode cores 22 include two negative high voltage electrodes, one is connected with the discharge rod 236, the other is connected with the reflective plate 231 and the grid plate 232, so that the reflective plate 231 and the grid plate 232 are equipotential and potential is higher than potential of the discharge rod 236, the grid plate 232 is provided with a plurality of beam outlet holes 2321 for emitting electron beams.

Because the reflecting polar plate 231 and the grid plate 232 are equipotential and have potentials higher than the potential of the discharging rod 236, electrons can be emitted in multiple directions to a semi-closed cylindrical space formed by the reflecting polar plate 231, the grid plate 232 and the two reflecting polar side plates 233 after the discharging rod 236 is electrified, the beam emitting direction is adjusted after the electrons are reflected, the electrons are finally and stably and uniformly released in the form of electron beams from the grid plate 232, the grid plate 232 is connected with negative high voltage, the electron beam outlet 24 on the vacuum cavity 21 is at zero potential, the electron beams are finally accelerated and uniformly emitted from the electron beam outlet 24, the irradiation sterilization of an object is realized, and the uniform beam emission ensures that the object to be sterilized has the best sterilization effect on the premise of consuming the lowest energy.

Preferably, the reflective electrode side plate 233 is provided with a connecting lug 2331, and the reflective electrode side plate 233 is connected to the inner wall of the reflective electrode plate 231 via the connecting lug 2331.

Preferably, the high voltage input device 1 and the electron beam output device 2 are isolated by a vacuum flange assembly 10, the vacuum flange assembly 10 includes a ceramic disk 101, the ceramic disk 101 is integrally cylindrical with one end closed and the other end open, a plurality of electrode cores 22 penetrate through the closed end of the ceramic disk 101, and the ceramic disk 101 sealsThe outer side surface of the closed end faces the vacuum cavity 21 and is provided with a plurality of annular convex edges 1011 which are coaxially arranged, the arrangement of the annular convex edges 1011 enables the outer side surface of the closed end of the ceramic disc 101 to present a section of wavy transition surface, and because the surface is in a vacuum environment, after the electrode core 22 is connected with high voltage, the surface generates a water wave-like electric arc from the center to the outer edge and climbs along the transition surface, namely, electrons crawl to the nearest edge position along the transition surface along the center position of the electrode core 22, and according to the voltage-resistant characteristic of ceramic materials, the vacuum degree in the vacuum cavity 21 is pumped to be lower than 10 in the embodiment^-2Pa, and according to the surface flashover characteristic of the ceramic insulating material, when the creepage distance is more than or equal to 2cm, the creepage phenomenon is hardly generated, therefore, the creepage distance is increased on the basis of not changing the disc diameter of the ceramic disc 101 by the arrangement of the annular convex edge 1011, the creepage phenomenon is hardly generated, the operation is safer and more stable, and the service life of the electron gun can be longer.

Preferably, the vacuum flange assembly 10 further includes a sealing sleeve 102 sleeved on the outer cylindrical side wall of the ceramic disc 101, the sealing sleeve 102 includes an annular connecting portion 1021 and a cylindrical sleeve portion 1022, the outer side of the cylindrical sleeve portion 1022 is sleeved with a quick-insertion flange 103, one end of the quick-insertion flange 103 abuts against one side of the annular connecting portion 1021, the other side of the annular connecting portion 1021 is connected with an annular flange 104, the edge of the inner ring of the annular flange 104 is transited by a smooth curved surface and is connected with the outer side surface of the closed end of the ceramic disc 101, the creepage distance is further increased, and meanwhile, the vacuum chamber 21 is sealed.

Preferably, a shielding cylinder 20 is arranged between the plurality of electrode cores 22 and the electron beam generating device 23, the shielding cylinder 20 can shield electrons emitted from the wires, and the electrons are prevented from being emitted to the vacuum cavity 21 to disturb the accelerating electric field, an annular concave 1012 is arranged on the outer side surface of the closed end of the ceramic disc 101, the electrode cores 22 are inserted into the closed end of the ceramic disc 101 in the inner concave 1012 ring, a shielding cylinder connecting piece 30 is clamped at the concave 1012, the shielding cylinder connecting piece 30 is connected with the end part of the shielding cylinder 20, and a ceramic sleeve 40 is sleeved on the outer side of the shielding cylinder connecting piece 30 to further shield the leakage of the electrons.

Preferably, the highest point of the annular rib 1011 is higher than any point of the sealing sleeve 102, that is, the outer side surface of the closed end of the ceramic disc 101 is not in the same plane with the annular connecting part 1021 of the sealing sleeve 102, which is also designed to avoid the creepage phenomenon.

Preferably, a step 1013 is provided at a position where the outer sidewall of the ceramic disc 101 is opposite to the inner sidewall of the sealing sleeve 102 and the annular flange 104, and the step 1013 forms a groove for filling solder after the ceramic disc 101 is assembled with the sealing sleeve 102 and the annular flange 104.

Preferably, the electron beam generator 23 includes an arc-shaped reflective plate 231 and a planar grid 232, two ends of the grid 232 are connected to the reflective plate side plates 233 at two sides, the arc-shaped reflective plate 231 has a high fault tolerance and can reflect the electrons emitted in all directions to finally irradiate the grid 232, the discharge rod 236 between the two holders 235 is a tungsten rod, the discharge efficiency is high, each holder 235 is connected with a pressing block 237 to press and fix one end of the tungsten rod, the holders 235 can conduct electricity to enable the tungsten rod and the negative high-voltage electrode to form a loop, the tungsten rod is arranged parallel to the grid 232, and the arrangement is helpful for enabling the electrons emitted from the tungsten rod to irradiate the grid 232 uniformly.

Preferably, the central angle corresponding to the arc on the cross section of the reflective plate 231 is 180 ° to 260 °, that is, the opening angle of the arc on which the reflective plate 231 is located is 100 ° to 180 °.

Preferably, the two ends of the grid plate 232 are provided with bending portions 2322 perpendicular to the plane of the grid plate 232, and the bending portions 2322 at the two ends respectively abut against the reflective electrode side plates 233 at the two ends of the grid plate 232.

Preferably, the vacuum chamber 21 includes a first chamber 211 and a second chamber 212 connected to each other, the first chamber 211 is provided with a vacuum device interface 2111 and a vacuum degree detection interface 2112 for respectively receiving a vacuum device and a vacuum degree detection device, and the second chamber 212 is provided with a window 2121 for observing the internal status of the electron gun.

Preferably, the beam outlet holes 2321 are arranged in a honeycomb shape, that is, each beam outlet hole 2321 has a regular hexagonal structure, which has high stability and can improve the uniformity of the emitted electrons.

Preferably, a lead through hole is provided in the repeller side plate 233 on the side close to the shield cylinder 20, and a ceramic ring is fitted in the lead through hole for insulation.

Preferably, the side wall of the vacuum chamber 21 is provided with electron beam outlets 24 at positions corresponding to the plurality of beam outlets 2321 of the grid plate 232, the electron beam outlets 24 are connected to an exit window 25 located outside the vacuum chamber 21, the exit window 25 includes a sealing seat 50, the sealing seat 50 is connected to a titanium window 60, the titanium window 60 is covered with a titanium film 70, a pressing plate 80 connected to the titanium window 60 for fixing the titanium film 70 is provided outside the titanium film 70, the electron beam is led out to the irradiated object through the titanium film 70, and the titanium film 70 is supported by the titanium window 60.

Preferably, the titanium window 60 comprises a plurality of support bars 601 which are arranged in parallel at equal intervals, the support bars 601 are arc-shaped, an arc-shaped flat hole 602 is formed between every two adjacent support bars 601, the flat hole 602 is arranged in a manner that the absorptivity of high-pressure deformation wrinkles of the titanium film 70 is considered, the titanium film 70 is sufficiently supported, the deformation influence generated by the titanium film 70 is minimized, a reinforcing rib 603 connected with every two adjacent support bars 601 is arranged in each flat hole 602, and the reinforcing ribs 603 in every two adjacent flat holes 602 are arranged in a staggered manner, so that the structural strength of the titanium window 60 is guaranteed.

Preferably, a ring of annular groove is arranged on the surface of the outer side of the titanium window 60, which is in contact with the titanium film 70, the aluminum wire 90 is embedded in the groove for metal sealing, and when the titanium film 70 deforms, the aluminum wire 90 can be used as an edge sealing and tightly adsorbed by the titanium film 70, so that the sealing performance inside the vacuum cavity 21 is improved.

Preferably, the seal holder 50 is provided with a recess 501 which is attached to the outer wall of the vacuum chamber 21.

Preferably, the high-voltage input device 1 comprises a cooling oil tank 100, cooling oil is input for insulation and cooling, the use safety of the high-voltage input device 1 is improved, the cooling oil adopts a standard of high-insulation oil, one end of the cooling oil tank 100 is connected with the vacuum flange assembly 10, the other end of the cooling oil tank is connected with a socket 200 inserted into the cooling oil tank 100, the socket 200 is connected with the electrode core 22 through a wire, and the cooling oil circulates in the cooling oil tank 100 to cool the wire and the electrode core 22, so that the service life of the high-voltage input device is prolonged.

Preferably, the cooling oil tank 100 is a rectangular parallelepiped, and includes an oil tank body 1001 and an oil tank cover 1002, the oil tank cover 1002 can be periodically opened to clean the internal environment of the cooling oil tank 100, the oil tank body 1001 is provided with an oil inlet 1003 and an oil outlet 1004 for the circulation of cooling oil, one end of the oil tank cover 1002 is connected to the socket 200 through a sealing flange 1005, the other end is connected to a sheet flange 1006 attached to the vacuum flange assembly 10, and the sealing flange 1005 and the sheet flange 1006 are both provided with rectangular recesses 1007 into which the ends of the oil tank body 1001 are inserted.

Preferably, the cross-shaped connector 201 is arranged at one end of the shielding cylinder 20 connected with the electron beam generating device 23, the cross-shaped connector 201 is connected with the inner wall of the shielding cylinder 20 in the radial direction of the shielding cylinder 20, and is connected with the electron beam generating device 23 in the axial direction of the shielding cylinder 20, so that the connection is convenient to disassemble and assemble.

Preferably, a chamber support base 213 is connected to the vacuum chamber 21.

The working principle of the invention is as follows: the high-voltage input device 1 is electrified, the internal circulating cooling oil cools the conducting wire and the electrode core 22, the tungsten rod, the reflecting polar plate 231 and the grid plate 232 are connected with negative high voltage, the potential of the reflecting polar plate 231 and the grid plate 232 is equal, the potential of the reflecting polar plate 231 and the potential of the grid plate 232 are all higher than that of the tungsten rod, electrons are diverged in all directions after the tungsten rod is electrified, the electrons are attracted by the reflecting polar plate 231, the reflecting polar plate 233 and the grid plate 232 and directly or indirectly ejected from the beam outlet holes 2321 of the grid plate 232 through reflection of the reflecting polar plate 231, and the electrons ejected from the beam outlet holes 2321 are finally accelerated and then uniformly ejected from the titanium film 70 of the beam outlet holes 24 because the electron beam outlet 24 on the vacuum cavity 21 is at zero potential.

The beam-emitting uniformity of the electron gun based on the structure is also related to the diameter of the arc where the reflecting polar plate 231 is located, the opening angle of the arc where the reflecting polar plate 231 is located, the size of the beam-emitting hole 2321 of the grid plate 232, the position of the tungsten rod and other factors.

The beam-out condition of the electron gun under two different sets of conditions is simulated in simulation software.

Group 1: the diameter of the arc where the reflecting plate 231 is located is 85mm, the opening angle of the arc where the reflecting plate 231 is located is 120 degrees, the diameter of the inscribed circle of the beam outlet 2321 of the grid plate 232 is 8mm, the center of the arc of the section of the reflecting plate 231 is taken as the origin, the grid plate 232 is 10mm below the origin, and the tungsten rod is 10mm above the origin.

Group 2: the diameter of the arc where the reflecting polar plate 231 is located is 85mm, the opening angle of the arc where the reflecting polar plate 231 is located is 120 degrees, the diameter of the inscribed circle of the beam outlet 2321 of the grid plate 232 is 4mm, the center of the arc of the cross section of the reflecting polar plate 231 is taken as the origin, the grid plate 232 is 20mm below the origin, and the tungsten rod is overlapped with the origin.

The group 1 and the group 2 are simultaneously carried out under the conditions that negative high voltage of 70KV is input at the tungsten rod, the irradiation time is 1 second, the current of the tungsten rod is 13.2mA, and the feedback current is 2.5 mA.

The simulation results are shown in fig. 14 and fig. 15, respectively, and it can be seen that the beam uniformity of the electron gun under the condition of group 2 is better.

Now, the conditions of the group 1 and the group 2 are kept unchanged, and further evidence is obtained through practical tests.

In the actual test, the irradiation sterilization color-changing indication label is used for detection, the label is a circular test paper with the diameter of 13mm, the color before irradiation is yellow, the color gradually changes into red according to the irradiation degree, and yellow, light red and deep red are defined as three grades of the label after irradiation and respectively correspond to grade I, grade II and grade III.

The actual test results are shown in fig. 16 and 17, respectively, and the lower right corner of each label in fig. 16 and 17 is the grade of the label after being irradiated, which is obtained after colorimetry, and it is verified that the beam uniformity of the electron gun under the condition of the group 2 is better.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned examples, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims (9)

1. An anti-creep electricity sterilization electron gun which characterized in that: comprises a high-voltage input device (1) and an electron beam output device (2); the electron beam output device (2) comprises a vacuum cavity (21), a plurality of electrode cores (22) with one ends connected with the high-voltage input device (1) are arranged in the vacuum cavity (21), the other ends of the electrode cores (22) are connected with an electron beam generating device (23) arranged in the vacuum cavity (21), and an electron beam outlet (24) is formed in the vacuum cavity (21); the high-voltage input device (1) and the electron beam output device (2) are isolated through the vacuum flange assembly (10), the vacuum flange assembly (10) comprises a ceramic disc (101), the ceramic disc (101) is integrally cylindrical with one closed end and the other open end, the electrode cores (22) penetrate through the closed end of the ceramic disc (101), and the outer side face of the closed end of the ceramic disc (101) faces towards the vacuum cavity (21) and is provided with a plurality of annular convex ribs (1011) which are coaxially arranged.

2. The electron gun as claimed in claim 1, wherein: vacuum flange subassembly (10) still including cover at sealing sleeve (102) of ceramic dish (101) cylinder lateral wall, sealing sleeve (102) are including annular connecting portion (1021) and cylindricality cover portion (1022), cylindricality cover portion (1022) outside cover has fast inserting flange (103), the one end of inserting flange (103) soon supports one side of annular connecting portion (1021), the opposite side of annular connecting portion (1021) is connected with annular flange (104), the edge of annular flange (104) inner circle is met by smooth curved surface transition and with the lateral surface of ceramic dish (101) blind end, and then forms the sealing to vacuum cavity (21).

3. The electron gun as claimed in claim 1, wherein: a plurality of be equipped with between electrode core (22) and electron beam generating device (23) and shield a section of thick bamboo (20), the lateral surface of ceramic dish (101) blind end is equipped with annular indent (1012), electrode core (22) alternates on ceramic dish (101) closed end with the inside of indent (1012) ring circle, indent (1012) department joint has a shielding section of thick bamboo connecting piece (30), shielding section of thick bamboo connecting piece (30) is connected with the tip of a shielding section of thick bamboo (20), shielding section of thick bamboo connecting piece (30) outside cover has ceramic cover (40).

4. The electron gun as claimed in claim 2, wherein: the highest point of the annular convex rib (1011) is higher than any point on the sealing sleeve (102).

5. The electron gun as claimed in claim 2, wherein: the outer side wall of the ceramic disc (101) is provided with a step (1013) at a position opposite to the inner side walls of the sealing sleeve (102) and the annular flange (104).

6. The electron gun as claimed in claim 1, wherein: the vacuum cavity (21) comprises a first cavity (211) and a second cavity (212) which are connected with each other, a vacuum equipment interface (2111) and a vacuum degree detection interface (2112) are arranged on the first cavity (211), and a window (2121) is arranged on the second cavity (212).

7. The electron gun as claimed in claim 1, wherein: the electron beam generating device (23) comprises a reflecting polar plate (231) and a grid plate (232), the reflecting polar plate (231) and the grid plate (232) are spliced into a tubular structure with two open ends, the open positions of the two ends are respectively covered with a reflecting polar plate (233), the two reflecting polar plates (233) are respectively connected with a fixing seat (235) through a ceramic column (234), two discharging rods (236) are fixed between the fixing seats (235), the equal potential and the potential of the reflecting polar plate (231) and the grid plate (232) are respectively higher than the potential of the discharging rods (236), and a plurality of beam outlet holes (2321) are formed in the grid plate (232).

8. The electron gun according to claim 7, wherein: the electron beam emission device is characterized in that electron beam emission openings (24) are formed in the side wall of the vacuum cavity (21) and correspond to a plurality of emission holes (2321) of the grid plate (232), the electron beam emission openings (24) are connected with emission windows (25) located outside the vacuum cavity (21), the emission windows (25) comprise sealing seats (50), titanium windows (60) are connected to the sealing seats (50) outwards, titanium films (70) cover the outer sides of the titanium windows (60), and pressing plates (80) connected with the titanium windows (60) and used for fixing the titanium films (70) are arranged on the outer sides of the titanium films (70).

9. The electron gun as claimed in claim 1, wherein: the high-voltage input device (1) comprises a cooling oil tank (100), one end of the cooling oil tank (100) is connected with the vacuum flange assembly (10), the other end of the cooling oil tank is connected with a socket (200) inserted into the cooling oil tank (100), and the socket (200) is connected with the electrode core (22) through a wire.

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