Vacuum vessel, electromagnetic wave generation system, and electromagnetic wave generation method

Abstract

To provide a vacuum vessel, electromagnetic wave generation system, and electromagnetic wave generation method that make output of an electromagnetic wave to be taken out be hardly reduced.SOLUTION: A vacuum vessel comprises a first vacuum structure that has a dielectric window for taking out a generated electromagnetic wave and can store a positive electrode and a negative electrode, a second vacuum structure into which an introduction terminal for supporting a support post of the positive electrode can be inserted, and a reflection part that is arranged inside the first vacuum structure and is formed using a metal member. The first vacuum structure and the second vacuum structure are arranged in parallel coaxially with an axis of the reflection part. An outer peripheral surface of the first vacuum structure extends along the axis and connects to the second vacuum structure. The reflection part includes a cylinder part having an axis and a wall part that has a hole coaxially with the axis and connects to the cylinder part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a vacuum vessel, an electromagnetic wave generating system, and an electromagnetic wave generating method. [Background technology]

[0002] It is known to use a virtual cathode oscillator as a means for emitting electromagnetic waves.

[0003] For example, Patent Document 1 describes a device that includes: "a plurality of cathodes arranged to face each other at the periphery of a waveguide; an anode having a plurality of anode terminals arranged between the cathodes in the waveguide and facing the cathodes at intervals; and a reflector electrically connected to the anode terminals of the anodes, and a reflector electrically connected to the anode terminals of the anodes and installed between the anode terminals." An output window for outputting the generated electromagnetic waves to the outside is formed at one end of the waveguide located on the opposite side from the anode. "A virtual cathode oscillator tube characterized by: [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-064573 Summary of the Invention [Problem to be solved by the invention]

[0005] When the electromagnetic waves generated by the virtual cathode oscillator tube disclosed in Patent Document 1 are extracted, a portion of the generated electromagnetic waves may be reflected by the output window and travel toward the anode. In this case, the output of the electromagnetic waves extracted from the output window may decrease.

[0006] An object of the present disclosure is to provide a vacuum vessel, an electromagnetic wave generating system, and an electromagnetic wave generating method that solve the above-mentioned problems. [Means for solving the problem]

[0007] The vacuum container of the present disclosure comprises a first vacuum structure having a dielectric window through which generated electromagnetic waves are extracted and capable of accommodating an anode and a cathode, a second vacuum structure through which an introduction terminal supporting a support post of the anode can be inserted, and a reflecting portion disposed inside the first vacuum structure and formed of a metal member, wherein the first vacuum structure and the second vacuum structure are disposed side by side coaxially with the axis of the reflecting portion, the outer peripheral surface of the first vacuum structure extends along the axis and is connected to the second vacuum structure, and the reflecting portion includes a cylindrical portion having the axis, and a wall portion having a hole coaxially with the axis and connected to the cylindrical portion.

[0008] The electromagnetic wave generating method of the present disclosure is characterized in that the electromagnetic wave generating system includes a cathode placed opposite an anode to which a high-voltage pulse is applied, or a cathode placed opposite the anode and to which a negative high-voltage pulse is applied, in a vacuum container having a dielectric window, the cathode including a carbon member having a microstructure on the surface facing the anode, and a base containing metal or graphite and on which the carbon member is provided, the carbon member and the base being bonded together by a carbon paste having heat resistance comparable to that of the carbon member, and electromagnetic waves are generated by applying a pulse voltage between the anode and the cathode. [Effects of the Invention]

[0009] According to the vacuum vessel, the electromagnetic wave generating system, and the electromagnetic wave generating method according to the present disclosure, the output of the extracted electromagnetic waves is less likely to decrease. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram I of an electromagnetic wave generating system according to the present disclosure. [Figure 2] FIG. 2 is a diagram showing the positional relationship of a “cathode-anode-virtual cathode” in an electromagnetic wave generating system according to the present disclosure. [Figure 3] 1 is a flowchart I showing an example of a process of a vacuum container manufacturing method according to the present disclosure. [Figure 4] 2 is a schematic configuration diagram II of an electromagnetic wave generating system according to the present disclosure. [Figure 5]1 is a cross-sectional view showing an example of the configuration of a vacuum container according to the present disclosure. [Figure 6] 10 is a flowchart II showing an example of a process of a vacuum container manufacturing method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. Note that the drawings and specific configurations used in each embodiment should not be used to interpret the disclosure. The same or corresponding configurations in all drawings will be assigned the same reference numerals, and common descriptions will be omitted. It should be noted that in this disclosure, the drawings may relate to one or more embodiments.

[0012] First Embodiment Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. An example of the configuration of an electromagnetic wave generating system according to the present disclosure will be described below with reference to FIGS.

[0013] (Configuration of electromagnetic wave generating system) The electromagnetic wave generating system 100 is used to generate electromagnetic waves. The virtual cathode oscillator 10 constituting the electromagnetic wave generating system 100 has a vacuum vessel 11, an anode 12, and a cathode 13 as its main components. The vacuum vessel 11 generates electromagnetic waves (denoted by the symbol W1) inside, and is provided on its side with a window 15 made of a dielectric material 14 for extracting the generated electromagnetic waves W1 to the outside.

[0014] A positive high voltage pulse is applied to the anode 12. Alternatively, a negative high voltage pulse may be applied to the cathode 13. The cathode 13 is disposed opposite the anode 12, with the opposing surface being disposed parallel to the anode surface 12A.

[0015] (Outline of the electromagnetic wave generation system) On the opposite side of the anode 12 from the cathode 13, electrons drawn from the cathode 13 pass through the anode 12, forming a virtual cathode V1. When a positive high voltage pulse is applied to the anode 12 and an electron beam is extracted from the cathode 13 arranged opposite the anode 12, the electrons extracted from the cathode 13 pass through the anode 12, and the virtual cathode V1 is formed on the opposite side of the cathode 13 across the anode 12. In this electromagnetic wave generating system 100, a virtual cathode V1, which is an area where electrons accumulate, is formed on the opposite side of the cathode 13 across the anode 12 inside the vacuum vessel 11, causing oscillatory accelerated motion of electrons between the cathode 13-anode 12-virtual cathode V1, and this motion generates an electromagnetic wave W1, which can be output to the outside through the window 15 in the dielectric 14.

[0016] (Vacuum vessel configuration) 1, the vacuum vessel 11 includes a first vacuum structure 11A, a second vacuum structure 11B, and a reflector 11C. The interior of the vacuum vessel 11 is maintained in a vacuum state. The vacuum state is maintained at a sufficiently high vacuum state so that electrons emitted from the cathode 13 and accelerated toward the anode 12 do not collide with gas molecules or the like during the process. The first vacuum structure 11A, the second vacuum structure 11B, and the reflecting portion 11C are made of a metal material such as stainless steel.

[0017] The first vacuum structure 11A can accommodate an anode 12 and a cathode 13. At the right end of the first vacuum structure 11A in the drawing, a dielectric 14 is provided to seal a window 15, for extracting electromagnetic waves W1 generated by the anode 12 and the cathode 13 to the outside. The traveling direction (the direction of arrow a1) of the extracted electromagnetic waves W1 is as shown in FIG. A lead-in terminal 17 that supports a support post 16 of anode 12 is inserted into second vacuum structure 11B. Lead-in terminal 17 supports anode 12 from the side via support post 16 made of a good conductor, and passes through and is supported by an insulating wall 18 that seals the left end of second vacuum structure 11B in the figure. The first vacuum structure 11A and the second vacuum structure 11B are arranged side by side coaxially with the axis Ax of the reflecting part 11C. From the external appearance of the vacuum vessel 11, it can be seen that the outer peripheral surface SA of the first vacuum structure 11A extends along the axis Ax and is connected to the second vacuum structure 11B.

[0018] The first vacuum structure 11A and the second vacuum structure 11B are cylindrical members. For example, the first vacuum structure 11A and the second vacuum structure 11B may be cylindrical members. For example, if the first vacuum structure 11A and the second vacuum structure 11B are cylindrical members, the inner diameter of the first vacuum structure 11A and the inner diameter of the second vacuum structure 11B may be the same, and the outer diameter of the first vacuum structure 11A and the outer diameter of the second vacuum structure 11B may be the same. This simplifies the structure of the vacuum vessel 11 compared to when the first vacuum structure 11A and the second vacuum structure 11B have different shapes. Even if the inner diameter or outer dimensions of the first vacuum structure 11A and the second vacuum structure 11B are different, they may be formed as a single unit.

[0019] The reflecting portion 11C is disposed inside the first vacuum structure 11A and is formed of a metal member. The reflecting portion 11C includes a cylindrical portion 11Ca and a wall portion 11Cb. The metal member suppresses transmission of the reflected wave that travels toward the second vacuum structure 11B as a result of the electromagnetic wave W1 being reflected by the window 15. The metal member may have a mesh structure. If the metal member is a one-dimensional, two-dimensional, or three-dimensional periodic structure, the opening of the periodic structure (the length between lines in the mesh structure) may be equal to or less than the wavelength of the electromagnetic wave W1. Depending on the suppression of transmission, the opening of the periodic structure may be equal to or less than 1 / 5 of the wavelength of the electromagnetic wave W1, or equal to or less than 1 / 10 of the wavelength of the electromagnetic wave W1. For example, if the output frequency of electromagnetic wave W1 is 3 GHz, and the wavelength is 10 cm, the mesh size of the periodic structure may be 10 cm or less. Depending on the degree of transmission suppression, the mesh size of the periodic structure may be 2 cm (1 / 5 of the wavelength) or 1 cm (1 / 10 of the wavelength). Calculating the transmission suppression effect based on equation (18) in the literature (K.F. Casey, “Electromagnetic Shielding Behavior of Wire-Mesh Screens,” IEEE Trans. on Electromagnetic Compatibility, vol. 30, no. 3, Aug. 1988), assuming a wire diameter of the metal component is 1 mm, the transmission suppression effect improves by approximately 6 dB when the mesh size of the periodic structure is 1 / 5, and by approximately 16 dB when the mesh size is 1 / 10, compared to when the mesh size is the same as the wavelength of electromagnetic wave W1 (here, 10 cm).

[0020] The reflecting portion 11C includes a tube portion 11Ca having an axis Ax. For example, the tube portion 11Ca is a cylindrical member. The wall portion 11Cb has a hole H coaxial with the axis Ax and is connected to the cylindrical portion 11Ca. The metal member may further include a wall portion 11Cc having a hole H coaxially with the axis Ax, thereby allowing the electromagnetic wave W1 that has leaked into the second vacuum structure 11B via the cylindrical portion 11Ca of the reflecting portion 11C to be reflected. The reflecting portion 11C is welded to the inside of the first vacuum structure 11A or the second vacuum structure 11B, or screwed to a terminal provided in the first vacuum structure 11A, thereby ensuring electrical connection between the reflecting portion 11C and the first vacuum structure 11A. For example, the wall portion 11Cb is electrically connected to the first vacuum structure 11A. Furthermore, when the vacuum vessel 11 further includes a wall portion 11Cc as in the vacuum vessel 11 of the present disclosure, the wall portion 11Cc is electrically connected to either the first vacuum structure 11A or the second vacuum structure 11B.

[0021] (Configuration of anode and cathode) A high-voltage pulse power supply 19 for applying a positive high-voltage pulse is connected to the lead-in terminal 17 of the anode 12. The other negative terminal of this high-voltage pulse power supply 19 is grounded. The cathode 13 has a cathode main body 13B supported from above on the wall surface of the first vacuum structure 11A by supports 16 made of a good conductor. As shown in FIG. 2, the cathode main body 13B includes a base 13Ba, a carbon member 13Bb, and a carbon paste 13Bc. The cathode main body 13B includes a carbon member 13Bb having a fine structure on a surface region 13α facing the anode 12. The finely structured carbon member 13Bb located on the surface region 13α provides an electric field concentration effect, thereby lowering the threshold electric field strength required for electron emission in the surface region 13α. As a result, the carbon member 13Bb of the present disclosure facilitates electron emission compared to when a flat surface structure is located on the surface region 13α, contributing to improved output from the virtual cathode oscillator tube 10. The carbon member 13Bb is provided on a base 13Ba made of a metal such as copper or aluminum, or graphite. When the base 13Ba contains graphite, the base 13Ba may be a graphite laminate structure or a body made of a carbon fiber reinforced carbon composite material. The material of the base 13Ba is preferably one that does not release gas in a vacuum, can withstand high temperatures, and has good electrical conductivity and good thermal conductivity. The same applies to the material of the anode 12. Examples of the carbon member 13Bb include carbon fiber felt and a three-dimensional structure formed of a plurality of carbon nanotubes. The carbon paste 13Bc bonds the base 13Ba and the carbon member 13Bb. The carbon paste 13Bc has high heat resistance comparable to that of the carbon member 13Bb. During electron emission, the cathode generates heat of approximately 2000°C. If a conductive resin is used for bonding, the conductive resin will melt or sublimate. This wear at the bonded portion reduces the durability of the cathode 13. Therefore, in the cathode 13 of the present disclosure, the carbon paste 13Bc is used to bond the base 13Ba and the carbon member 13Bb, thereby improving the durability of the cathode 13 compared to when a resin-based adhesive or the like is used. Reducing the number of times the cathode needs to be replaced using the carbon paste 13Bc reduces the operating costs of the electromagnetic wave generating system 100. The carbon paste 13Bc may have the same level of conductivity as the carbon member 13Bb. A film of a metal material such as nickel, titanium, chromium, or copper may be formed on the adhesive surface of the carbon member 13Bb. In this case, two or more layers of different metals may be formed on the adhesive surface. Sputtering or the like is used for the film formation. This can further improve the adhesiveness between the carbon member Bb and the carbon paste Bc. Similarly, a film of the above metal material may be formed on the adhesive surface of the base 13Ba.

[0022] The cathode 13 may also be used in other oscillator tubes such as a magnetron, a klystron, a magnetically insulated line oscillator (MILO), a backward-wave oscillator (BWO), a traveling wave tube, etc.

[0023] For example, a coaxial cylindrical cathode 13 and anode 12 may be used. It is conceivable that the cylindrical cathode 13 is disposed inside the vacuum vessel 11, and the cylindrical anode 12, which is one size larger than the cathode 13, is disposed coaxially with the cathode 13 so as to surround the cathode 13.

[0024] The anode 12 has a structure that allows electrons drawn from the cathode 13 to pass through the anode 12, and for example, a mesh structure made of a conductive material is adopted. However, the structure of the anode 12 through which electrons can pass is not limited to this, and it may be a thin film with a thickness on the order of microns or less. The mesh structure has the advantage that it is easy to make a mechanically strong structure or to fabricate a highly durable anode 12 by making the non-penetrating portions thicker. On the other hand, the thin film has the advantage that there is no distinction between portions through which electrons can pass and portions through which they cannot, and the electron permeability is uniform, resulting in uniform characteristics.

[0025] In such a virtual cathode oscillator tube 10, when a positive high voltage pulse of several hundred kV is supplied from the high voltage pulse power supply 19 to the anode 12 in the vacuum vessel 11 via the lead-in terminal 17, an electric field is generated between the anode 12 and the cathode 13, and electrons are drawn out from the cathode 13 and accelerated from the cathode 13 toward the anode 12. The electrons extracted from the surface of the cathode 13 continue to accelerate until they reach the position of the anode 12, at which point they reach a maximum speed, and most of them pass through the anode 12. After passing through the anode 12, the electrons are accelerated again toward the anode 12 and eventually stop moving, after which they start moving toward the anode 12 again.

[0026] The region where these electrons reside is called the virtual cathode V1. That is, when a positive high voltage pulse is applied to the anode 12 and an electron beam is extracted from the cathode 13 arranged opposite the anode 12, the electrons extracted from the cathode 13 pass through the anode 12, and the virtual cathode V1 is formed on the opposite side of the cathode 13 across the anode 12. In such a virtual cathode oscillator 10, electromagnetic waves W1 are generated by the oscillatory accelerated motion of electrons in the "cathode 13-anode 12-virtual cathode V1" configuration, and the generated electromagnetic waves W1 are extracted to the outside through the window 15 in the dielectric 14.

[0027] (Vacuum vessel creation method) A method for producing the vacuum vessel 11 in this disclosure will be described. The method for producing the vacuum vessel 11 in the present disclosure is carried out according to the flow shown in FIG.

[0028] First, the operator prepares the first vacuum structure 11A and the second vacuum structure 11B (step ST10: preparing step). The first vacuum structure 11A has a window 15 in a dielectric 14 through which the generated electromagnetic wave W1 is extracted, and has a structure capable of accommodating the anode 12 and the cathode 13. The second vacuum structure 11B has a structure capable of inserting a lead-in terminal that supports a support post 16 of the anode 12.

[0029] Next, the worker forms the reflecting portion 11C using a metal member (step ST20: forming step). The reflecting portion 11C is formed of a metal member. The reflecting portion 11C includes a cylindrical portion 11Ca and a wall portion 11Cb. The metal member suppresses the transmission of the electromagnetic wave W1. The metal member may have a mesh structure. If the metal member is a one-dimensional, two-dimensional, or three-dimensional periodic structure, an operator can adjust the mesh size of the periodic structure according to the degree of transmission suppression.

[0030] Next, the worker places the reflecting portion 11C inside the first vacuum structure 11A (step ST30: placing step). At this time, the reflecting portion 11C is welded to the inside of the first vacuum structure 11A or the second vacuum structure 11B or screwed to a terminal provided in the first vacuum structure 11A, thereby ensuring electrical connection between the reflecting portion 11C and the first vacuum structure 11A. For example, the wall portion 11Cb is electrically connected to the first vacuum structure 11A. Furthermore, when the vacuum vessel 11 further includes a wall portion 11Cc as in the vacuum vessel 11 of the present disclosure, the wall portion 11Cc is electrically connected to either the first vacuum structure 11A or the second vacuum structure 11B. In this way, the vacuum vessel 11 used in the electromagnetic wave generating system 100 is completed. (Complete)

[0031] (Cathode creation method) A method for producing the cathode 13 in this embodiment will be described. The cathode 13 is disposed opposite the anode 12 to which a high voltage pulse is applied, and the opposing surface region 13α is disposed parallel to the surface of the anode 12.

[0032] First, the worker prepares the base 13Ba containing metal or graphite and the carbon member 13Bb having a microstructure in the surface region 13α.

[0033] Next, the worker bonds the base 13Ba and the carbon member 13Bb with a carbon paste 13Bc having heat resistance similar to that of the carbon member 13Bb. The carbon paste 13Bc has heat resistance similar to that of the carbon member 13Bb. The carbon paste 13Bc may have electrical conductivity similar to that of the carbon member 13Bb. During bonding, the worker may form a film of a metal material such as nickel, titanium, chromium, or copper on the bonding surface of the carbon member 13Bb or the base 13Ba, and then bond the carbon member 13Bb to the base 13Ba. Sputtering or the like is used for forming the film. In this way, the cathode 13 used in the electromagnetic wave generating system 100 is completed. (Complete)

[0034] (Action and effect) According to the vacuum vessel 11 of this embodiment, a reflector 11C is disposed inside the first vacuum structure 11A. The reflector 11C is formed of a metal member. As a result, when the electromagnetic wave W1 collides with the wall portion 11Cb of the metal member, an impedance mismatch occurs for the electromagnetic wave W1, and fixed-end reflection of the electromagnetic wave W1 occurs at the wall portion 11Cb, causing resonance between the electromagnetic wave W1 and the reflected wave. The reflector 11C suppresses the complex reflected wave via the cylindrical portion 11Ca, thereby more accurately controlling resonance. Furthermore, by suppressing reflection at the window 15 of the dielectric 14 and strengthening the transmitted wave, it is possible to strengthen the output of the electromagnetic wave of the desired frequency. As described above, in the vacuum vessel 11 of the present disclosure, the output of the electromagnetic waves extracted from the output window is less likely to decrease.

[0035] By adjusting the length of the reflecting portion 11C, the vacuum vessel 11 can suppress electromagnetic waves W1 leaking from the first vacuum structure 11A through the cylindrical portion 11Ca of the reflecting portion 11C to the second vacuum structure 11B.

[0036] When the output frequency of the electromagnetic wave W1 is changed, the position of the cathode 13 in the first vacuum structure 11A and the length L1 along the axis Ax of the first vacuum structure 11A are changed. When designing the output frequency band, the position of the cathode 13 in the vacuum vessel 11 and the length of the first vacuum structure 11A of the vacuum vessel 11, which affect the oscillation, propagation, transmission, reflection, etc. of the electromagnetic wave W1, are dominant. Therefore, the length of the cylindrical portion 11Ca of the reflecting portion 11C along the axis Ax may be changed according to the length L1, which allows the output frequency band to be changed without creating a vacuum vessel 11 according to the output frequency band.

[0037] The distance in the propagation direction (direction of arrow a1) of the electromagnetic wave W1 between the center position of the cathode 13 in the first vacuum structure 11A and the wall portion 11Cb of the reflecting portion 11C located opposite the window 15 of the first vacuum structure 11A may be made to coincide with the position of the antinode of the standing wave generated by the fixed-end reflection of the electromagnetic wave W1 of the desired frequency. This not only prevents the electromagnetic wave W1 of the desired frequency generated in the area of ​​the cathode 13 from canceling each other out, but also aligns the phases of the propagating wave and the reflected wave, making them reinforce each other. By appropriately setting the distance between the center position of the cathode 13 in the first vacuum structure 11A and the window 15 of the first vacuum structure 11A, it is possible to suppress reflection of the dielectric 14 at the window 15 and strengthen the transmitted wave. At the window 15, a part of the electromagnetic wave W1 is reflected by the free end.

[0038] A comparative example of a vacuum vessel will now be described. The comparative example of a vacuum vessel may have a structure consisting of three vacuum vessels (vacuum vessels a, B, and C). For example, vacuum vessel A has a dielectric window for extracting the generated electromagnetic waves to the outside and houses an anode and a cathode. Vacuum vessel A extracts electrons and generates a virtual cathode. Vacuum vessel B, which houses a feedthrough that supports the anode pole, introduces a high-voltage pulse to the electrode. Vacuum vessel C suppresses electromagnetic waves leaking from either vacuum vessel A or B to the other vacuum vessel. Vacuum vessel C has a different diameter from vacuum vessels A and B to intentionally create an impedance mismatch. However, connecting three cylinders of different diameters makes the vacuum vessel structure complex and expensive. Also, because vacuum vessel C is connected to vacuum vessels A and B, which have larger diameters, a structure to reinforce the joint of vacuum vessel C is required, which makes it even more expensive.

[0039] To address the above-mentioned concerns about price, the vacuum vessel 11 of the present disclosure is characterized in that a portion of the vacuum vessel C is made of metal mesh and is located inside the vacuum vessel A. This allows the number of types of vacuum vessel diameters to be reduced to two: vacuum vessel A and vacuum vessel B.

[0040] Furthermore, by substituting a metal member for the thinnest diameter vacuum vessel C, there is no need for a structure to reinforce the joint of the vacuum vessel C in the "vacuum vessel B-vacuum vessel C-vacuum vessel A" structure. Therefore, the vacuum vessel can be produced more inexpensively.

[0041] (Variation) In the above disclosure, a positive high voltage pulse is applied to the anode 12 , but a positive high voltage pulse may be applied to the cathode 13 .

[0042] Furthermore, the vacuum vessel 11 of the present disclosure "includes a first vacuum structure 11A having a window 15 in a dielectric 14 through which the generated electromagnetic wave W1 is extracted and capable of accommodating an anode 12 and a cathode 13, a second vacuum structure 11B into which an input terminal 17 supporting a support 16 of the anode 12 can be inserted, and a reflecting portion 11C arranged inside the first vacuum structure 11A and formed of a metal member, the first vacuum structure 11A and the second vacuum structure 11B being arranged side by side coaxially with the axis Ax of the reflecting portion 11C, the outer peripheral surface SA of the first vacuum structure 11A extending along the axis Ax and connected to the second vacuum structure 11B, and the reflecting portion 11C including a tubular portion 11Ca having the axis Ax, and a wall portion 11Cb having a hole coaxially with the axis Ax and connected to the tubular portion 11Ca," thereby achieving the following effects. According to the vacuum vessel 11 of the present disclosure, a reflecting portion 11C is disposed inside the first vacuum structure 11A. The reflecting portion 11C is formed of a metal member. This provides the following effect: "When the electromagnetic wave W1 collides with the wall portion 11Cb of the metal member, an impedance mismatch occurs for the electromagnetic wave W1, and fixed-end reflection of the electromagnetic wave W1 occurs at the wall portion 11Cb, causing resonance between the electromagnetic wave and the reflected wave. The reflecting portion 11C suppresses the complex reflected waves that pass through the tubular portion 11Ca, thereby controlling the resonance more accurately, and further suppressing reflection at the window 15 of the dielectric 14 and strengthening the transmitted waves, making it possible to strengthen the output of the electromagnetic wave of the desired frequency." Therefore, in the vacuum vessel 11 of the present disclosure, the output of the electromagnetic waves extracted from the output window is less likely to decrease.

[0043] Additionally, in the vacuum vessel 11 of the present disclosure, "the first vacuum structure 11A and the second vacuum structure 11B are cylindrical members", which also provides the effect that "the vacuum vessel 11 is easy to manufacture".

[0044] Furthermore, in the vacuum vessel 11 of the present disclosure, "the metal member has a mesh structure," which "can increase the exhaust conductance, which indicates the ease of gas flow in vacuum exhaust. Since the gas in the vacuum vessel 11 can pass through the reflecting portion 11C, which has a mesh structure, the effective inner diameter of the piping is increased by having the mesh structure, and the exhaust conductance is improved." This also has the effect of achieving this effect.

[0045] Furthermore, in the vacuum vessel 11 of the present disclosure, the mesh size of the periodic structure (the length between the lines of the mesh structure) can be changed depending on the suppression of permeation.

[0046] Second Embodiment Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. An example of the configuration of an electromagnetic wave generating system according to the present disclosure will be described below with reference to FIG. In addition, components common to those disclosed above are given the same reference numerals and detailed description thereof will be omitted.

[0047] (Configuration of electromagnetic wave generating system) As shown in FIG. 4, the virtual cathode oscillator tube 20 constituting the electromagnetic wave generating system 200 has a vacuum vessel 11′, an anode 12, and a cathode 13 as its main components. The vacuum vessel 11' differs in configuration from the vacuum vessel 11 in the shape of the first vacuum structure 11A' and the cylindrical member 11d.

[0048] (Vacuum vessel configuration) The vacuum vessel 11' includes a first vacuum structure 11A', a second vacuum structure 11B, a reflecting portion 11C, and a cylindrical member 11d. Unlike the first vacuum structure 11A, the first vacuum structure 11A' has the same dimensions as the second vacuum structure 11B. In the following disclosure, the first vacuum structure 11A' and the second vacuum structure 11B are cylindrical members, and the inner diameter of the first vacuum structure 11A' is the same as the inner diameter of the second vacuum structure 11B, and the outer diameter of the first vacuum structure 11A' is the same as the outer diameter of the second vacuum structure 11B. This allows the first vacuum structure 11A' and the second vacuum structure 11B to be formed as a single unit. This simplifies the structure of the vacuum vessel 11' compared to when the first vacuum structure 11A and the second vacuum structure 11B have different shapes. In the following disclosure, the first vacuum structure 11A' and the second vacuum structure 11B are also arranged side by side and coaxial with the axis Ax of the reflecting portion 11C. From the outside of the vacuum vessel 11, the outer circumferential surface SA' of the first vacuum structure 11A' extends along the axis Ax and is connected to the second vacuum structure 11B. The outer circumferential surface SA' of the first vacuum structure 11A' coincides with the outer circumferential surface SB of the second vacuum structure 11B.

[0049] The cylindrical member 11d is disposed inside the first vacuum structure 11A and extends along the axis Ax. The cylindrical member 11d is made of the same metal material as the reflecting portion 11C, and therefore the metal material in the cylindrical member 11d may have the same mesh structure as disclosed above.

[0050] One wall portion (11Cb) of the reflecting portion 11C is connected to the cylindrical member 11d. As described above, the cylindrical member 11d and the reflecting portion 11C are formed of the same metal material. Therefore, the cylindrical member 11d and the reflecting portion 11C may be formed integrally.

[0051] (Action and effect) According to the vacuum vessel 11' of this embodiment, a reflector 11C is disposed inside the first vacuum structure 11A'. The reflector 11C is formed of a metal member. As a result, when the electromagnetic wave W1 collides with the wall portion 11Cb of the metal member, an impedance mismatch occurs for the electromagnetic wave W1, and fixed-end reflection of the electromagnetic wave W1 occurs at the wall portion 11Cb, causing resonance between the electromagnetic wave W1 and the reflected wave. The reflector 11C suppresses the complex reflected wave that passes through the cylindrical portion 11Ca, thereby controlling resonance more accurately. Furthermore, by suppressing reflection at the window 15 of the dielectric 14 and strengthening the transmitted wave, it is possible to strengthen the output of the electromagnetic wave of the desired frequency. As described above, in the vacuum vessel 11' of the present disclosure, the output of the electromagnetic waves extracted from the output window is less likely to decrease.

[0052] Third Embodiment Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. An example of the configuration of the vacuum vessel in this disclosure will be described below with reference to FIG.

[0053] (composition) The vacuum vessel 11m has a window 15m in a dielectric 14m through which the generated electromagnetic waves are extracted, and is equipped with a first vacuum structure 11Am capable of accommodating an anode 12m and a cathode 13m, a second vacuum structure 11Bm through which an input terminal 17m supporting a support 16m of the anode 12m can be inserted, and a reflective portion 11Cm arranged inside the first vacuum structure 11Am and formed of a metal member, the first vacuum structure 11Am and the second vacuum structure 11Bm being arranged side by side coaxially with the axis Axm of the reflective portion 11Cm, the outer peripheral surface SAm of the first vacuum structure 11Am extending along the axis Axm and connected to the second vacuum structure 11Bm, and the reflective portion 11Cm including a tubular portion 11Cam having the axis Axm, and a wall portion 11Cbm having a hole Hm coaxially with the axis Axm and connected to the tubular portion 11Cam.

[0054] (Action and effect) According to the vacuum vessel 11m of the present disclosure, a reflector 11Cm is disposed inside the first vacuum structure 11Am. The reflector 11Cm is formed of a metal member. As a result, when an electromagnetic wave collides with a wall 11Cbm of the metal member, an impedance mismatch occurs for the electromagnetic wave, and fixed-end reflection of the electromagnetic wave occurs at the wall 11Cbm, causing resonance between the electromagnetic wave and the reflected wave. The reflector 11Cm more accurately controls resonance by suppressing the complex reflected wave that passes through the cylindrical portion 11Cam. Furthermore, by suppressing reflection at the window 15m of the dielectric 14m and strengthening the transmitted wave, it is possible to strengthen the output of the electromagnetic wave of the desired frequency. As described above, in the vacuum vessel 11m of the present disclosure, the output of the electromagnetic waves extracted from the output window is less likely to decrease.

[0055] The vacuum vessel of the above-mentioned oscillator tube (including magnetron, etc.) tends to have a complicated structure, which makes the manufacturing of the vacuum vessel expensive.

[0056] To address the above-mentioned concern about the price, the vacuum vessel 11m of the present disclosure has a reflecting portion 11Cm inside the vacuum vessel 11m to generate impedance mismatch. This makes it easy to make the vacuum vessel 11m in a simple shape. In other words, the vacuum vessel 11m is less expensive to manufacture.

[0057] <Fourth embodiment> Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. An example of a method for producing a vacuum vessel according to the present disclosure will be described below with reference to FIG. The manufacturing method according to the present disclosure is carried out according to the flow shown in FIG.

[0058] The method for creating a vacuum vessel includes the steps of: preparing a first vacuum structure (ST10m) having a dielectric window through which generated electromagnetic waves are extracted and capable of housing an anode and a cathode; and a second vacuum structure through which an introduction terminal supporting a support post of the anode can be inserted; forming a reflecting portion using a metal member; and arranging the reflecting portion inside the first vacuum structure (ST20m), wherein the reflecting portion includes a cylindrical portion and a wall portion having a hole coaxial with the axis of the cylindrical portion and connected to the cylindrical portion.

[0059] (Action and effect) According to the vacuum vessel manufacturing method of the present disclosure, a reflector is disposed inside the first vacuum structure. The reflector is formed of a metal member. As a result, when an electromagnetic wave collides with the wall of the metal member, an impedance mismatch occurs for the electromagnetic wave, and fixed-end reflection of the electromagnetic wave occurs at the wall, causing resonance between the electromagnetic wave and the reflected wave. The reflector suppresses the complex reflected wave that passes through the cylindrical portion, thereby more accurately controlling resonance, and further suppresses reflection at the dielectric window and strengthens the transmitted wave, thereby enabling the output of electromagnetic waves of a desired frequency to be strengthened. As described above, in the method for producing a vacuum vessel according to the present disclosure, the output of the electromagnetic waves extracted from the output window is less likely to decrease.

[0060] The vacuum vessel of the above-mentioned oscillator tube (including magnetron, etc.) tends to have a complicated structure, which makes the manufacturing of the vacuum vessel expensive.

[0061] To address the above-mentioned concerns about price, the vacuum container manufacturing method of the present disclosure arranges a reflecting portion 11 inside the vacuum container to generate impedance mismatch. This makes it easy to make the vacuum container into a simple shape. In other words, the vacuum container manufactured by this vacuum container manufacturing method is unlikely to be expensive.

[0062] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0063] A part or all of the above disclosure may be described as, but is not limited to, the following supplementary notes.

[0064] (Appendix 1) a first vacuum structure having a dielectric window for extracting the generated electromagnetic waves and capable of accommodating an anode and a cathode; a second vacuum structure through which a lead-in terminal supporting the anode pole can be inserted; a reflecting portion disposed inside the first vacuum structure and formed of a metal member; Equipped with the first vacuum structure and the second vacuum structure are arranged side by side coaxially with an axis of the reflecting portion, an outer periphery of the first vacuum structure extends along the axis and connects to the second vacuum structure; The reflecting portion is a cylindrical portion having the axis; a wall portion having a hole coaxial with the shaft and connected to the cylindrical portion; Contains vacuum container.

[0065] (Appendix 2) a tubular member disposed within the first vacuum structure and extending along the axis; the cylindrical member is formed from the metal member, One of the wall portions and the cylindrical member are connected. 1. A vacuum vessel as described in Appendix 1.

[0066] (Appendix 3) The first vacuum structure and the second vacuum structure are cylindrical members. 1. A vacuum vessel according to claim 1 or 2.

[0067] (Appendix 4) The inner diameter dimension of the first vacuum structure and the inner diameter dimension of the second vacuum structure are the same, The outer diameter of the first vacuum structure is the same as the outer diameter of the second vacuum structure. 1. A vacuum vessel as described in Appendix 3.

[0068] (Appendix 5) The metal member has a mesh structure. 10. A vacuum vessel according to any one of claims 1 to 4.

[0069] (Appendix 6) The metal member has a mesh structure with openings equal to or smaller than the wavelength of the electromagnetic wave. 1. A vacuum vessel as described in Appendix 5.

[0070] (Appendix 7) The mesh structure has an opening size of 1 / 5 or less of the wavelength of the electromagnetic wave. 1. A vacuum vessel as described in Appendix 6.

[0071] (Appendix 8) The mesh structure has an opening size of 1 / 10 or less of the wavelength of the electromagnetic wave. 1. A vacuum vessel as described in Appendix 6.

[0072] (Appendix 9) a vacuum vessel according to any one of Supplementary Note 1 to Supplementary Note 8; a cathode disposed opposite to an anode to which a high voltage pulse is applied, the cathode having an opposing surface disposed parallel to the surface of the anode; the anode; Equipped with Electromagnetic wave generating system.

[0073] (Appendix 10) providing a first vacuum structure having a dielectric window for extracting the generated electromagnetic waves and capable of accommodating an anode and a cathode, and a second vacuum structure into which a lead-in terminal supporting a support post of the anode can be inserted; forming a reflecting portion using a metal member; placing the reflector within a first vacuum structure; Including, The reflecting portion is A cylindrical portion and a wall portion having a hole coaxial with the axis of the cylindrical portion and connected to the cylindrical portion; Contains How to create a vacuum vessel.

[0074] (Appendix 11) a cathode disposed opposite to an anode to which a high voltage pulse is applied, or a cathode disposed opposite to an anode to which a negative high voltage pulse is applied, a carbon member having a microstructure on a surface facing the anode; a base including metal or graphite and on which the carbon member is provided; Equipped with The carbon member and the base are bonded together by a carbon paste having heat resistance comparable to that of the carbon member. cathode.

[0075] (Appendix 12) A metal material is formed on the adhesive surface of the carbon member or the base. 12. The cathode of claim 11.

[0076] (Appendix 13) The carbon member is a three-dimensional structure formed of carbon fiber felt or a plurality of carbon nanotubes. 13. The cathode of claim 11 or 12.

[0077] (Appendix 14) A cathode disposed opposite to an anode to which a high voltage pulse is applied, providing a base including metal or graphite and a carbon member having a microstructure on its surface; bonding the base and the carbon member together with a carbon paste having heat resistance comparable to that of the carbon member; Contains How to make a cathode.

[0078] (Appendix 15) In the bonding step, a copper film is formed on the bonding surface of the carbon member or the base via a metal material, and then the carbon member and the base are bonded together. 15. A method for making a cathode according to claim 14.

[0079] (Appendix 16) An electromagnetic wave generating system including, in a vacuum vessel having a dielectric window, a cathode disposed opposite an anode to which a high voltage pulse is applied, or a cathode disposed opposite the anode and to which a negative high voltage pulse is applied, a carbon member having a microstructure on a surface facing the anode; and a base containing metal or graphite on which the carbon member is provided, and a cathode to which the carbon member and the base are bonded with a carbon paste having heat resistance comparable to that of the carbon member; and an electromagnetic wave generating method characterized by applying a pulse voltage between the anode and the cathode. [Explanation of symbols]

[0080] 10 Virtual Cathode Oscillator 11 Vacuum container 11' vacuum container 11A First vacuum structure 11C Reflector 11Ca cylinder part 11Cb wall 11Cc wall 11B Second vacuum structure 11A' First vacuum structure 11d Cylindrical member 11m vacuum container 11Am First vacuum structure 11Bm second vacuum structure 11Cm Reflector 11Cam cylinder part 11Cbm wall 12 Anode 12A anode surface 12m anode 13 Cathode 13A Post 13B Cathode main body 13Ba base 13Bb Carbon material 13Bc carbon paste 13m cathode 13α surface area 14 Dielectrics 14m dielectric 15. Window 15m window 16 pillars 16m pole 17 Lead-in terminal 17m lead-in terminal 18 Wall 19 High voltage pulse power supply 20 Virtual Cathode Oscillator 100 Electromagnetic Wave Generating System 200 Electromagnetic Wave Generating System a1 arrow Ax axis Axm axis H hole Hm hole SA outer surface SA' outer surface SAm outer surface SB outer surface V virtual cathode V1 Virtual Cathode W1 electromagnetic wave

Claims

1. a first vacuum structure having a dielectric window for extracting the generated electromagnetic waves and capable of accommodating an anode and a cathode; a second vacuum structure through which a lead-in terminal supporting the anode pole can be inserted; a reflecting portion disposed inside the first vacuum structure and formed of a metal member; Equipped with the first vacuum structure and the second vacuum structure are arranged side by side coaxially with an axis of the reflecting portion, an outer periphery of the first vacuum structure extends along the axis and connects to the second vacuum structure; The reflecting portion is a cylindrical portion having the axis; a wall portion having a hole coaxial with the shaft and connected to the cylindrical portion; Contains vacuum container.

2. a tubular member disposed within the first vacuum structure and extending along the axis; the cylindrical member is formed from the metal member, One of the wall portions and the cylindrical member are connected. The vacuum vessel according to claim 1 .

3. The first vacuum structure and the second vacuum structure are cylindrical members.

3. The vacuum vessel according to claim 1 or 2.

4. The inner diameter dimension of the first vacuum structure and the inner diameter dimension of the second vacuum structure are the same, The outer diameter of the first vacuum structure is the same as the outer diameter of the second vacuum structure. The vacuum vessel according to claim 3 .

5. The metal member has a mesh structure.

3. The vacuum vessel according to claim 1 or 2.

6. The metal member has a mesh structure with openings equal to or smaller than the wavelength of the electromagnetic wave. The vacuum vessel according to claim 5 .

7. The mesh structure has an opening size of 1 / 5 or less of the wavelength of the electromagnetic wave. The vacuum vessel according to claim 6.

8. The vacuum vessel according to claim 1 or 2; a cathode disposed opposite to an anode to which a high voltage pulse is applied; the anode; Equipped with Electromagnetic wave generating system.

9. a carbon member having a microstructure on a surface facing the anode; a base including metal or graphite and on which the carbon member is provided; Equipped with The carbon member and the base are bonded together by a carbon paste having heat resistance comparable to that of the carbon member.

9. The electromagnetic wave generating system according to claim 8.

10. An electromagnetic wave generating system including, in a vacuum vessel having a dielectric window, a cathode disposed opposite an anode to which a high voltage pulse is applied, or a cathode disposed opposite the anode and to which a negative high voltage pulse is applied, a carbon member having a microstructure on a surface facing the anode; and a base containing metal or graphite on which the carbon member is provided, and a cathode to which the carbon member and the base are bonded with a carbon paste having heat resistance comparable to that of the carbon member; and an electromagnetic wave generating method characterized by applying a pulse voltage between the anode and the cathode.

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