Laser electron gun assembly

Abstract

The present invention relates to a laser electron gun assembly. A first through hole is formed in a mounting base, a light window base is mounted in the first through hole, one end of an optical fiber is connected to a laser generator, the other end of the optical fiber is connected to a focusing and collimating lens, the focusing and collimating lens is connected to one end of the light window base, a light window is mounted at the other end of the light window base in a sealed manner, a cathode assembly is mounted on the mounting base by means of a focusing electrode, and a laser beam emitted by the laser generator passes through the optical fiber, is focused by the focusing and collimating lens, and then passes through the light window to form a light spot on the cathode assembly. According to the laser electron gun assembly of the present invention, the laser beam emitted by the laser generator forms electrons for irradiating an accelerator, so that the structure is simple, and the manufacturing cost is low; moreover, the laser electron gun assembly of the present invention fundamentally overcomes the defect in the prior art of using motors to drive high-voltage generators to supply power to lamp filaments, so that the overall size is greatly reduced, the diameter is generally smaller than 70 mm, and the laser electron gun assembly is easy to carry and use.

Description

Laser electron gun assembly Technical Field

[0001] The present invention relates to an irradiation accelerator, and more particularly to a laser electron gun assembly. Background Art

[0002] Electron gun assemblies are known to be used to generate electrons for irradiation accelerators. Existing electron gun assemblies use a motor to drive a generator mounted on the head to generate current. This current is then heated via two electrodes to heat a tungsten filament. The kinetic energy of the thermal electrons generated by the heated tungsten filament is greater than the work function, causing the electrons to leave the tungsten filament surface and form an electron cloud near the filament. Heating the tungsten filament requires a continuous current of approximately 20A. The accelerator beam size is adjusted by adjusting the generator's rotational speed, thereby varying the heating current of the filament. Clearly, existing electron gun assemblies require a continuous power supply to the head, which introduces numerous drawbacks. First, the overall size of the electron gun assembly is large, both in terms of overall height and diameter, reaching, for example, 140mm in diameter. Second, the electron gun assembly has numerous components, a complex structure, high manufacturing costs, and significant manufacturing difficulty. Third, the electron gun assembly requires a continuous power supply to heat the tungsten filament, resulting in high energy consumption. Summary of the Invention

[0003] In order to solve the problems of large volume and the like in the above-mentioned prior art, the present invention provides a laser electron gun assembly.

[0004] According to the laser electron gun assembly of the present invention, it includes a laser generator, a mounting base, a light window base, a focusing collimating lens, an optical fiber, a light window, a focusing electrode and a cathode assembly, wherein the mounting base is provided with a first through hole, the light window base is mounted in the first through hole, one end of the optical fiber is connected to the laser generator, the other end of the optical fiber is connected to the focusing collimating lens, the focusing collimating lens is connected to one end of the light window base, the light window is sealed and mounted at the other end of the light window base, the cathode assembly is mounted on the mounting base via the focusing electrode, and the laser beam emitted by the laser generator passes through the optical fiber and is focused by the focusing collimating lens, then passes through the light window to form a light spot on the cathode assembly.

[0005] Preferably, the focusing electrode has a transverse partition, the transverse partition is provided with an annular groove, and the cathode assembly is mounted in the annular groove.

[0006] Preferably, the cathode assembly includes a cathode and a heat-insulating ceramic ring, the light spot is formed on the cathode, and the heat-insulating ceramic ring is embedded in the annular groove of the transverse partition.

[0007] Preferably, the cathode is a tungsten plate with a rough surface.

[0008] Preferably, the focusing electrode has a flange, and the focusing electrode is connected to the mounting seat via the flange.

[0009] Preferably, the focusing electrode has a flange, the mounting seat has a groove, and the flange is inserted into the groove for installation.

[0010] Preferably, the light window base is provided with a first internal thread, the end of the optical fiber is provided with a coupling joint, the coupling joint is provided with a second internal thread, and the two ends of the focusing collimating lens respectively have a first and a second external thread, the first external thread cooperates with the first internal thread, and the second external thread cooperates with the second internal thread.

[0011] Preferably, the light window base has an annular embedding groove, and the light window is sealed and installed in the annular embedding groove.

[0012] Preferably, the laser generator is a laser generating device that can continuously emit infrared laser or green laser.

[0013] Preferably, the first through hole is a stepped hole.

[0014] The laser electron gun assembly of the present invention utilizes a laser beam emitted by a laser generator to generate electrons for irradiating an accelerator. It features a simple structure and low manufacturing cost. Furthermore, the laser electron gun assembly of the present invention fundamentally avoids the drawbacks of prior art technologies that rely on a motor to drive a high-voltage generator to power the filament. Its overall size is significantly reduced, typically to a diameter of less than 70 mm, making it easy to carry and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a schematic diagram of the overall structure of a laser electron gun assembly according to a preferred embodiment of the present invention.

[0016] FIG2 is a partial cross-sectional view of FIG1 .

[0017] FIG. 3 is a first exploded view of FIG. 1 .

[0018] FIG. 4 is a second exploded view of FIG. 1 .

[0019] FIG5 is a schematic structural diagram of the mounting base of FIG1 .

[0020] FIG6 is a schematic structural diagram of the focusing collimating lens in FIG1 .

[0021] FIG. 7 is a schematic structural diagram of the focusing electrode in FIG. 1 . DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0023] As shown in Figures 1 to 4, a laser electron gun assembly according to a preferred embodiment of the present invention includes a laser generator (not shown), a mounting base 1, a light window base 2, a focusing collimating lens 3, an optical fiber 4, a light window 5, a focusing electrode 6 and a cathode assembly 7, wherein the mounting base 1 is a part of the irradiation accelerator, and the mounting base 1 is connected to a voltage multiplier assembly with a high voltage of 5 MeV. As shown in Figure 5, a first through hole 11 is provided in the center of the mounting base 1. As shown in Figure 2, the first through hole 11 is a stepped hole, and the light window base 2 is mounted on the first through hole from the top of the mounting base 1. In 11, the upper end of the light window base 2 is connected to the lower end of the focusing collimating lens 3, the upper end of the focusing collimating lens 3 is connected to the optical fiber 4, the optical fiber 4 is connected to the laser generator, the light window 5 is sealed and mounted on the lower end of the light window base 2, the focusing electrode 6 is mounted on the lower end of the mounting base 1, and the cathode assembly 7 is mounted on the focusing electrode 6 below the light window 5, so that the laser beam emitted by the laser generator passes through the light window 5 after being focused by the focusing collimating lens 3, and forms a light spot with a diameter of 3.5 mm on the cathode assembly 7, thereby forming an electron cloud for irradiating the accelerator.

[0024] The laser generator is a laser generating device capable of generating high-power, high-energy continuous infrared laser light or green laser light. In this embodiment, the laser generator is a laser generator capable of emitting infrared laser light with a wavelength of 1064 nm. In another embodiment, the laser generator is a laser generator capable of emitting green laser light with a wavelength of 532 nm.

[0025] The light window base 2 is a tubular structure. An internal thread is provided at the upper end of the light window base 2, as shown in Figure 6. The lower end of the focusing collimating lens 3 has an external thread 31, which mates with the internal thread at the upper end of the light window base 2. The lower end of the light window base 2 has an annular groove, into which the light window 5 is sealed, for example, with a sealant.

[0026] Among them, the end of the optical fiber 4 is provided with a coupling joint 41, and the lower end of the coupling joint 41 is provided with an internal thread, as shown in Figure 6, the upper end of the focusing collimating lens 3 has an external thread 32, and the external thread 32 cooperates with the internal thread of the lower end of the coupling joint 41.

[0027] The light window 5 is made of sapphire with a light transmittance of ≥90%.

[0028] As shown in Figure 7, the focusing electrode 6 has a flange 61. As shown in Figure 5, the mounting base 1 has a groove 12, into which the flange 61 is inserted for installation (see Figure 2). As shown in Figure 7, the focusing electrode 6 has a flange 62, which is connected to the lower end of the mounting base 1 via the flange 62. Furthermore, as shown in Figure 2, the focusing electrode 6 also has a transverse partition 63, which has an annular groove, into which the cathode assembly 7 is mounted. It should be understood that the area below the optical window 5 is a vacuum environment.

[0029] The cathode assembly 7 comprises a cathode 71 and an insulating ceramic ring 72. A light spot is formed on the cathode 71. The cathode 71 is heated to 2500 degrees Celsius, causing the kinetic energy of the electrons to exceed the work function, and the electrons leave the surface of the cathode 71 to form an electron cloud. The insulating ceramic ring 72 is embedded in the annular groove of the transverse partition 63, and the cathode 71 is fixed to the transverse partition 63 via the insulating ceramic ring 72. It should be understood that the heating of the cathode 71 by the laser beam is confined to the cathode 71 by the insulating ceramic ring 72. In this embodiment, the cathode 71 is a tungsten plate with a rough surface, which increases the contact area between the laser beam and the cathode 71, accelerating the heating rate of the cathode 71. The diameter of the light spot formed by the infrared laser beam focused on the cathode 71 by the focusing collimating lens 3 is 3.5 mm. It should be understood that the size of the light spot can be adjusted as needed by adjusting the distance between the cathode 71 and the focusing collimating lens 3 and the parameters of the focusing collimating lens 3 (such as focal length, diameter, and shape).

[0030] According to a preferred embodiment of the present invention, a method for forming electrons for an irradiation accelerator includes the following steps: S1, turning on the power of a laser generator to generate an infrared or green laser beam; S2, the laser beam is transmitted to a focusing collimating lens 3 through an optical fiber 4; S3, the focusing collimating lens 3 focuses the laser beam; S4, the focused laser beam enters a vacuum chamber inside a focusing electrode 6 through an optical window 5; S5, a light spot formed by the focused laser beam is irradiated onto the surface of a cathode 71 to heat the cathode 71; S6, the cathode 71 is heated until the kinetic energy of the electrons is greater than the work function, and the electrons leave the surface of the cathode 71 to form an electron cloud; S7, the focusing electrode 6 confines and gathers the scattered electrons.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A laser electron gun assembly, characterized in that: The laser electron gun assembly includes a laser generator, a mounting base, a light window base, a focusing collimating lens, an optical fiber, a light window, a focusing electrode, and a cathode assembly. The mounting base is provided with a first through hole, the light window base is mounted in the first through hole, one end of the optical fiber is connected to the laser generator, the other end of the optical fiber is connected to the focusing collimating lens, the focusing collimating lens is connected to one end of the light window base, the light window is sealed and mounted on the other end of the light window base, and the cathode assembly is mounted on the mounting base via the focusing electrode. The laser beam emitted by the laser generator passes through the optical fiber and is focused by the focusing collimating lens, then passes through the light window to form a light spot on the cathode assembly.

2. The laser electron gun assembly according to claim 1, characterized in that: The focusing electrode has a transverse partition, the transverse partition is provided with an annular groove, and the cathode assembly is installed in the annular groove.

3. The laser electron gun assembly according to claim 2, characterized in that: The cathode assembly includes a cathode and a heat-insulating ceramic ring. The light spot is formed on the cathode. The heat-insulating ceramic ring is embedded in the annular groove of the transverse partition.

4. The laser electron gun assembly according to claim 3, characterized in that: The cathode is a tungsten plate with a rough surface.

5. The laser electron gun assembly according to claim 1, characterized in that: The focusing electrode has a flange, and the focusing electrode is connected to the mounting seat through the flange.

6. The laser electron gun assembly according to claim 5, characterized in that: The focusing electrode has a flange, and the mounting seat has a groove, and the flange is inserted into the groove for mounting.

7. The laser electron gun assembly according to claim 1, characterized in that: The light window base is provided with a first internal thread, the end of the optical fiber is provided with a coupling joint, the coupling joint is provided with a second internal thread, and the two ends of the focusing collimating lens are respectively provided with a first and a second external thread, the first external thread cooperates with the first internal thread, and the second external thread cooperates with the second internal thread.

8. The laser electron gun assembly according to claim 1, characterized in that: The light window base is provided with an annular embedding groove, and the light window is sealed and installed in the annular embedding groove.

9. The laser electron gun assembly according to claim 1, characterized in that: The laser generator is a laser generating device that can continuously emit infrared laser or green laser.

10. The laser electron gun assembly according to claim 1, characterized in that: The first through hole is a stepped hole.

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