A terahertz electron gun

Abstract

The present invention discloses a terahertz electron gun, comprising a tip cathode (1), a cavity cathode end plate (2), a cavity (3), a cavity outlet end plate (4) and a beam hole (5); the tip cathode (1) and the cavity cathode end plate (2) are an integral structure, and in an area inside the cavity (3), where the field strength is the highest inside the cavity (3), the surface of the tip cathode (1) emits electrons under the action of a strong electric field; the cavity cathode end plate (2), the cavity (3) and the cavity outlet end plate (4) are independent components connected to form a whole; the beam hole (5) is located at the center of the cavity outlet end plate (4) and is used to extract a beam. The invention has a simple and compact structure, is easy to process, and is easy to use. The electron gun has a simple and compact structure, establishes a terahertz field inside the cavity, and when the electric field amplitude exceeds the field emission condition, the cathode surface emits electrons to generate an ultrashort femtosecond pulse beam, while overcoming the pulse jitter problem.

Description

Technical Field

[0001] The present invention relates to the field of accelerators, and in particular to a terahertz electron gun. Background Art

[0002] The cathodes used in electron guns to generate electron sources primarily include thermal cathodes, photocathodes, and field emission cathodes. Traditional field emission cathodes emit electrons under the influence of a strong electrostatic field (GV / m), with the pulse width determined by the pulse width of the electrostatic high voltage. For terahertz accelerators, the required bunch pulse width is less than 100 femtoseconds, with jitter less than 10 femtoseconds. Conventional voltage pulse widths and photocathode-driven lasers struggle to meet these requirements. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the present invention provides a terahertz electron gun, which solves the problem of the electron source of the terahertz band accelerator.

[0004] In order to achieve the above object, the technical solution adopted by the present invention to solve the technical problem is:

[0005] A terahertz electron gun comprises a pointed cathode 1, a cavity cathode end plate 2, a cavity 3, a cavity exit end plate 4, and a beam aperture 5. The pointed cathode 1 and cavity cathode end plate 2 are integrally structured and located within the cavity 3. The field strength at this location is the highest within the cavity 3, and the surface of the pointed cathode 1 emits electrons under the influence of the strong electric field. The cavity cathode end plate 2, cavity 3, and cavity exit end plate 4 are independent components connected to form a single unit. The beam aperture 5 is located at the center of the cavity exit end plate and is used to extract the beam.

[0006] Furthermore, a terahertz field is established inside the cavity. When the electric field amplitude exceeds the field emission condition, electrons are emitted from the cathode surface. When the electric field amplitude does not meet the field emission condition, no electrons are emitted, forming a pulse beam.

[0007] Furthermore, the top of the pointed cathode 1 is an arc, and the connection with the cavity cathode end plate 2 is a chamfer.

[0008] Furthermore, the top of the pointed cathode 1 is an arc, and the connection with the cavity cathode end plate 2 is an angle.

[0009] Furthermore, the terahertz electron gun is used to generate a femtosecond pulsed electron beam.

[0010] Advantages and positive effects:

[0011] The invention has the following beneficial effects: The invention has a simple and compact structure, is easy to process, and is readily practical. The electron gun has a simple and compact structure, establishes a terahertz field within the cavity, and when the electric field amplitude exceeds the field emission condition, electrons are emitted from the cathode surface, generating an ultrashort femtosecond pulse beam while overcoming the pulse jitter problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic structural diagram of a terahertz electron gun according to embodiment 1 of the present invention;

[0013] Figure 2 This is a schematic structural diagram of a terahertz electron gun according to embodiment 2 of the present invention.

[0014] In the figure: 1 is the tip cathode, 2 is the cavity cathode end plate, 3 is the cavity, 4 is the cavity outlet end plate, and 5 is the beam hole. DETAILED DESCRIPTION

[0015] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. However, the following embodiments are intended only to explain the present invention, and the scope of protection of the present invention should include the entire contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement the entire contents of the claims of the present invention.

[0016] Example 1

[0017] like Figure 1 As shown: A terahertz electron gun includes a tip cathode 1, a cavity cathode end plate 2, a cavity 3, a cavity exit end plate 4, and a beam hole 5. The top of the tip cathode 1 is an arc, and the connection with the cavity cathode end plate 2 is a chamfer.

[0018] The tip cathode 1 and the cavity cathode end plate 2 are an integral structure, without the need for welding, and are located in the inner area of the cavity 3. The field strength here is the highest in the cavity 3, and the surface of the tip cathode 1 emits electrons under the action of the strong electric field.

[0019] The cavity cathode end plate 2, cavity 3, and cavity exit end plate 4 are independent components connected to form a whole. A terahertz field is established within cavity 3. When the electric field amplitude exceeds the field emission condition, electrons are emitted from the cathode surface. When the electric field amplitude does not meet the field emission condition, no electrons are emitted, forming a pulsed beam.

[0020] The beam hole 5 is located at the center of the exit end plate of the cavity 3 and is used to lead out the beam.

[0021] Example 2

[0022] like Figure 2 As shown, a terahertz electron gun has a tip cathode 1 with an arc top and an angle at the connection with the cavity cathode end plate 2. The structure of the remaining parts is the same as that of Example 1.

[0023] In summary, the present invention provides a terahertz electron gun for generating a femtosecond pulsed electron beam.

[0024] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A terahertz electron gun, characterized in that: It includes a tip cathode (1), a cavity cathode end plate (2), a cavity (3), a cavity outlet end plate (4) and a beam hole (5); The tip cathode (1) and the cavity cathode end plate (2) are an integral structure. In the inner region of the cavity (3), the field strength there is the highest field strength inside the cavity (3). The surface of the tip cathode (1) emits electrons under the action of a strong electric field. The cavity cathode end plate (2), the cavity (3) and the cavity outlet end plate (4) are independent components, which are connected to form a whole. A terahertz field is established inside the cavity (3). When the electric field amplitude exceeds the field emission condition, electrons are emitted from the cathode surface. When the electric field amplitude does not meet the field emission condition, no electrons are emitted, forming a pulse beam. The beam hole (5) is located at the center of the cavity outlet end plate (4) and is used to lead out the beam. The top of the tip cathode (1) is an arc, and the connection with the cavity cathode end plate (2) is a chamfer, or the top of the tip cathode (1) is an arc, and the connection with the cavity cathode end plate (2) is an angle.

2. The electron gun according to claim 1, wherein The terahertz electron gun is used to generate femtosecond pulsed electron beam.

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