Electron tube

Abstract

An electron tube (100) is provided with: a cathode (3) that emits hot electrons; an anode in which a plurality of anode strips (4) are disposed so as to surround the cathode (3) in an anode cylinder (2) inside the anode cylinder structure (1), and which forms a cavity resonator; an input unit in which a cathode lead (5) to which an input voltage is applied is disposed; an output unit that emits microwaves to the outside; and a waveguide (W1) that transmits microwaves, a sealable shield case (9) that surrounds a part of the cathode lead (5) is joined to the outer surface of the anode cylinder structure (1) on the input section side, the sealable waveguide (W1) is joined to the outer surface of the anode cylinder structure (1) on the output section side, and the anode cylinder structure is provided with a communication hole (12). The communication hole has a first opening (11) that opens in a region surrounded by the shield housing (9) and a second opening (12) that opens in the waveguide (W1).

Description

Technical Field

[0001] The present invention relates to a vacuum tube, and particularly to a vacuum tube for outputting high-power microwaves. Background Art

[0002] In order to increase the power of medical and non-destructive inspection Linac (linear accelerator) systems, etc., it is necessary to improve the insulation breakdown voltage of the vacuum tube as the microwave oscillation source and the transmission path for transmitting the microwaves output from the vacuum tube. For example, it is necessary to improve the breakdown voltage of the input section where a high input voltage is applied in a magnetron that is the microwave oscillation source, and it is necessary to increase the breakdown voltage (high-frequency breakdown voltage against in-tube arc generation) in the waveguide that transmits the microwaves output from the magnetron.

[0003] In order to improve the breakdown voltage of the input section of the magnetron, for example, Patent Document 1 discloses a structure in which a rod-shaped conductor (corresponding to the cathode lead) to which a high voltage is applied is covered with an insulator such as silicone rubber. In addition, in order to increase the breakdown voltage of the waveguide for transmitting microwaves, for example, Patent Document 2 discloses a technique of maintaining the inside of the waveguide in an atmosphere such as sulfur hexafluoride (SF6) gas or high vacuum.

[0004] Prior Art Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 5-74356

[0006] Patent Document 2: Japanese Patent Laid-Open No. 2006-245978

[0007] As described above, by covering the input section of the magnetron with an insulator to improve the insulation between the terminals to which the voltage is applied, the input voltage can be increased to about 20 kV. As a result, the output power of the vacuum tube can be increased to about 80 kW.

[0008] However, with the demand for higher power of the vacuum tube, for example, it is required to increase the output power of the magnetron to 3 MW or more. In this case, the input voltage of the magnetron needs to be about 46 kV, for example. Such high-power microwaves can be transmitted by filling the inside of the waveguide with pressurized dry air, sulfur hexafluoride gas with high insulation performance, or by maintaining the inside of the waveguide in a vacuum state. However, such a high-power magnetron cannot adopt a structure covered with an insulator such as silicone rubber due to heat conduction and heat radiation from the cathode and the anode that becomes hot during operation. Therefore, it is necessary to improve the breakdown voltage of the input section of the magnetron by other insulation structures.

[0009] In order to improve the withstand voltage of the input section of a magnetron, a structure can be considered in which, for example, the input section is covered with a hermetically sealable housing and an insulating oil or a gas with high insulating properties is filled inside the housing. However, since the input section is at a high temperature, there is a possibility that the insulating oil or gas may leak from the housing due to thermal expansion. To prevent leakage, a complex structure for absorbing the pressure caused by the expansion is required. In addition, in a structure where gas is filled inside the housing, an injection port for injecting the gas is needed. Furthermore, a complex structure for maintaining a pressurized state and detecting the pressurized state after injecting the gas is required. From this perspective, it is also difficult to adopt such a structure. Summary of the Invention

[0010] Therefore, an object of the present invention is to provide a vacuum tube that can improve the withstand voltage of the input section without forming a complex structure and can achieve high power.

[0011] Means for Solving the Problem

[0012] One embodiment of the vacuum tube of the present invention is configured as a vacuum tube including: a cathode that emits thermoelectrons; an anode in which a plurality of anode plates are arranged in an anode cylinder inside an anode cylinder structure so as to surround the cathode, and a cavity resonator is formed between the anode plates; an input section that leads out a cathode lead for applying an input voltage to the cathode; an output section that emits microwaves excited by the cavity resonator to the outside; and a waveguide that transmits the microwaves emitted from the output section. Among them, a hermetically sealable shielding housing that surrounds a part of the cathode lead is joined to the outer side surface of the anode cylinder structure on the output section side, the hermetically sealable waveguide is joined to the outer side surface of the anode cylinder structure on the output section side, and the anode cylinder structure is provided with a communication hole that has a first opening that opens in a region surrounded by the shielding housing and a second opening that opens inside the waveguide.

[0013] Advantages of the Invention

[0014] According to the vacuum tube of the present invention, since it is configured to have a communication hole that has openings in a region surrounded by a shielding housing that covers a part of the cathode lead and inside a waveguide that transmits microwaves emitted from the output section, and the cathode lead applies an input voltage to the cathode, the inside of the waveguide that transmits high-power microwaves and the inside of the shielding housing are connected, the withstand voltage of the input section is improved, and a high-power vacuum tube can be provided. Description of the Drawings

[0015] Figure 1 It is a cross-sectional schematic view of a vacuum tube (Embodiment 1) as one embodiment of the present invention.

[0016] Figure 2It is a cross-sectional schematic view of a vacuum tube (Embodiment 2) as another embodiment of the present invention.

[0017] Figure 3 It is a cross-sectional schematic view of a vacuum tube (Embodiment 3) as yet another embodiment of the present invention.

[0018] Figure 4 It is a cross-sectional schematic view of a vacuum tube (Embodiment 4) as yet another embodiment of the present invention.

[0019] Figure 5 It is a cross-sectional schematic view of a vacuum tube (Embodiment 5) as yet another embodiment of the present invention.

[0020] Figure 6 It is a partial enlarged view of the joint portion of the third hole portion and the second hole portion constituting the communication hole in Embodiment 5.

[0021] Figure 7 It is a cross-sectional schematic view of a vacuum tube (Embodiment 6) as yet another embodiment of the present invention.

[0022] Figure 8 It is a partial enlarged view of the joint portion of the fourth hole portion and the second hole portion constituting the communication hole in Embodiment 6. Detailed Embodiments

[0023] The vacuum tube of the present invention is described with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, and components and the like described below can be variously changed within the scope of the gist of the present invention. In addition, in the drawings, the same reference numerals denote the same or equivalent things, and the size, positional relationship, etc. between the respective components are for convenience of explanation and do not strictly reflect the actual situation.

[0024] A shielding case is joined to the outer side surface of the anode cylinder structure on the input portion side of the vacuum tube of the present invention. The shielding case can seal and surround a part of the cathode lead wire led out and exposed from the anode cylinder structure. A waveguide that can be sealed is joined to the outer side surface of the anode cylinder structure on the output portion side. Further, the anode cylinder structure is configured to include a communication hole having a first opening that opens in a region surrounded by the shielding case and a second opening that opens in the waveguide.

[0025] The vacuum tube configured in this way can connect the inside of the waveguide and the inside of the shielding case. For example, when pressurized dry air, sulfur hexafluoride gas with high insulation performance, or the inside of the waveguide is set to a vacuum state is filled in the waveguide for transmitting high-power microwaves, the inside of the shielding case connected by the communication hole is also filled with pressurized dry air or sulfur hexafluoride gas, or becomes a vacuum state, and the withstand voltage of the input portion can be improved. As a result, high power of the vacuum tube can be achieved.

[0026] (Embodiment 1)

[0027] First, Embodiment 1 of the electron tube of the present invention will be described. Figure 1 It is a cross-sectional schematic diagram for explaining Embodiment 1 of the electron tube of the present invention, and is a cross-sectional schematic diagram perpendicular to the tube axis direction of the anode cylinder. As Figure 1 shown, the electron tube 100 of the present embodiment is configured such that a waveguide W1 is joined to the output portion of the magnetron M1. The magnetron M1 is the same as a general magnetron, and a cylindrical anode cylinder 2 is formed inside the anode cylinder structure 1, and a plurality of anode vanes 4 are arranged radially. One end of each anode vane 4 is joined to the inner wall of the anode cylinder 2 to form an anode having a ground potential. A cathode 3 is arranged at the center of the radially arranged anode vanes 4. The anode vane 4 may also be integrated with the anode cylinder 2, as long as a cavity resonator is formed in the space surrounded by the anode vane and the anode cylinder 2.

[0028] The cathode 3 is applied with a negative voltage equivalent to the anode voltage as an input voltage from the cathode lead 5 led out to the input portion. In addition, it is heated by a heater (not shown) and emits thermoelectrons. Figure 1 As shown, both ends of the cathode 3 shown are supported by the cathode leads 5 from a direction perpendicular to the central axis of the cathode 3, and the two cathode leads 5 are led out to the input portion. The side surface of the anode cylinder structure 1 where the cathode lead 5 is led out becomes the "outer side surface of the anode cylinder structure on the input portion side".

[0029] Magnetic circuits (not shown) are arranged on both side surfaces of the anode cylinder structure 1 in the tube axis direction of the anode cylinder 2, and a magnetic field is formed along the axial direction of the cathode 3 in the anode cylinder 2 through the magnetic circuits. Electrons emitted from the cathode 3, which is at a negative voltage with respect to the anode having a ground potential, are affected by the electric field and the magnetic field, and start to perform a circular motion in the action space between the cathode 3 and the front end of the anode vane 4, and resonate in the cavity resonator formed between the anode vanes 4 to excite microwaves. The microwaves are output from the antenna 6 at the output portion to the waveguide W1. The antenna 6 covered by the antenna cover 7 protrudes, and the side surface of the anode cylinder structure 1 where the waveguide W1 is joined becomes the "outer side surface of the anode cylinder structure on the output portion side".

[0030] In a high-power electron tube 100, it is necessary to improve the withstand voltage between the cathode lead 5 of the magnetron M1 to which a negative high voltage is applied as an input voltage and the anode cylinder structure 1 having a ground potential. As Figure 1As shown, the cathode lead 5 connected to the cathode 3 is fixed to the anode cylinder structure 1 by the insulating member 8. Further, the anode cylinder structure 1 is sealed by the insulating member 8, and the cathode lead 5 is exposed from the vacuum container including the anode cylinder 2. In the magnetron M1 having such a structure, it is easy to generate discharge or the like between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1. Therefore, the electron tube 100 of the present embodiment hermetically engages the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input portion side so as to surround a part of the cathode lead 5 exposed from the vacuum container. By configuring in this way, it is possible to surround a part of the cathode lead 5 and a part of the anode cylinder structure 1 where discharge or the like is likely to occur originally by the shielding case 9. Further, the anode cylinder structure 1 includes a communication hole 12 having a first opening 10 opening in the region surrounded by the shielding case 9 and a second opening 11 opening in the waveguide W1.

[0031] Figure 1 The electron tube 100 of the present embodiment shown in the figure is configured such that the input portion from which the cathode lead 5 of the magnetron M1 is led out and the output portion where the antenna 6 is disposed and microwaves are emitted to the outside are arranged in a direction perpendicular to the tube axis direction of the anode cylinder 2 with the anode cylinder 2 interposed therebetween. Further, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the end surface of the circular waveguide or the E-plane of the rectangular waveguide. Therefore, the communication hole 12 is configured such that the first hole portion 12a having the first opening 10 and the second hole portion 12b having the second opening 11 are directly connected, and the communication hole 12 has the first opening 10 opening in the region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input portion side and the second opening 11 opening in the waveguide W1 on the outer side surface of the anode cylinder structure 1 on the output portion side. When configured in this way, it is possible to arrange the communication hole 12 without increasing the area of the anode cylinder structure 1 surrounded by the shielding case 9 and the area of the anode cylinder structure 1 surrounded by the waveguide W1. In addition, the communication hole 12 configured in this way can be easily formed by forming the linear first hole portion 12a from the outer side surface of the anode cylinder structure 1 on the input portion side and then forming the linear second hole portion 12b from the outer side surface of the anode cylinder structure 1 on the output portion side.

[0032] For the electron tube 100 of the present embodiment that can be used as an oscillation source of microwaves, for example, a waveguide W1 that transmits microwaves is connected to a Linac system. In order to improve the electric breakdown strength of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W1, or a vacuum state is maintained inside the waveguide. In such a usage mode, the electron tube 100 of the present embodiment connects the inside of the waveguide W1 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed on the outer side surface of the anode cylinder structure 1. Therefore, the inside of the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or a vacuum state is maintained. As a result, it is possible to prevent discharges between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, and it is possible to achieve high withstand voltage of the input section.

[0033] As an example, when the inside of the waveguide W1 and the inside of the shielding case 9 are filled with dry air and the pressure is set to 2.5 kg / cm 2 , an electron tube with an input voltage of 46 V and an output power of 3 MW can be formed.

[0034] (Embodiment 2)

[0035] Next, Embodiment 2 of the electron tube of the present invention will be described. Figure 2 FIG. is a cross-sectional schematic view for explaining Embodiment 2 of the electron tube of the present invention, and is a cross-sectional view of the anode cylinder 2 in the tube axis direction. As Figure 2 shown, the electron tube 200 of the present embodiment is configured such that a waveguide W2 is joined to the output section of the magnetron M2. Similar to the magnetron M1 described in the above Embodiment 1, the magnetron M2 has a cathode 3 and anode vanes 4 disposed inside an anode cylinder 2 formed inside a rectangular anode cylinder structure 1. Hereinafter, the structures of the input section, output section, and communication hole 12 of the magnetron M2 will be mainly described in detail.

[0036] Figure 2 As shown in FIG., the electron tube 200 of the present embodiment is configured such that the input section from which the cathode lead 5 of the magnetron M2 is led out is disposed in the tube axis direction of the anode cylinder 2, and the output section that disposes an antenna 6 and emits microwaves to the outside is disposed in a direction perpendicular to the tube axis direction of the anode cylinder 2. In addition, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the end face of the circular waveguide or the E-plane of the rectangular waveguide.

[0037] A pair of annular magnets 13a and 13b and a magnetic yoke (not shown) are disposed on both side surfaces of the anode cylinder structure 1 at both ends in the tube axis direction of the anode cylinder 2, and they constitute a magnetic circuit. The magnetic forces of the magnets 13a and 13b of this magnetic circuit are applied to the action space between the front ends of the cathode 3 and the anode vanes 4 through the pole pieces 14a and 14b, respectively.

[0038] Figure 2 The cathode 3 shown is configured to be supported from the central axis direction of the cathode 3 by the cathode lead 5, and the cathode lead 5 is led out to the input section. The side surface of the anode cylinder structure 1 from which the cathode lead 5 is led out becomes the "outer side surface of the anode cylinder structure on the input section side". In addition, the antenna 6 covered by the antenna cover 7 protrudes, and the side surface of the anode cylinder structure 1 to which the waveguide W2 is joined becomes the "outer side surface of the anode cylinder structure on the output section side".

[0039] As Figure 2 shown, the cathode lead 5 connected to the cathode 3 is fixed to the anode cylinder structure 1 by the insulating member 8. In addition, the anode cylinder structure 1 is sealed by the insulating member 8, and the cathode lead 5 is exposed from the vacuum vessel including the anode cylinder 2. In order to prevent discharge or the like between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, in the electron tube 200 of the present embodiment, the shielding case 9 is also hermetically joined to the outer side surface of the anode cylinder structure 1 on the input section side so as to surround a part of the cathode lead 5 exposed from the vacuum vessel. By configuring in this way, it is possible to surround a part of the cathode lead 5 and a part of the anode cylinder structure 1 that are liable to generate discharge or the like by the shielding case 9. Further, the anode cylinder structure 1 is provided with a communication hole 12, and the communication hole 12 has a first opening 10 that opens in the region surrounded by the shielding case 9 and a second opening 11 that opens in the waveguide W2.

[0040] Figure 2 The electron tube 200 of the present embodiment shown is configured such that the input section from which the cathode lead 5 of the magnetron M2 is led out is arranged along the tube axis direction of the anode cylinder 2. In addition, it is configured such that the output section where the antenna 6 is arranged and microwaves are emitted to the outside is arranged in a direction perpendicular to the tube axis direction of the anode cylinder 2, and the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the end face of the circular waveguide or the E-plane of the rectangular waveguide. Therefore, the communication hole 12 is configured such that the first hole portion 12a having the first opening 10 and the second hole portion 12b having the second opening 11 are directly connected, and the communication hole 12 has the first opening 10 that opens in the region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input section side and the second opening 11 that opens in the waveguide W2 on the outer side surface of the anode cylinder structure 1 on the output section side. The communication hole 12 configured in this way can be easily formed by forming the linear first hole portion 12a from the outer side surface of the anode cylinder structure 1 on the input section side and then forming the linear second hole portion 12b from the outer side surface of the anode cylinder structure 1 on the output section side. In the present embodiment, the communication hole 12 can be provided by using only a relatively small area of the anode cylinder structure 1. Therefore, when the communication hole 12 is provided, other structures such as a cooling water passage provided in the anode cylinder structure 1 do not become a problem.

[0041] Also in the electron tube 200 of the present embodiment that can be used as an oscillation source of microwaves, in order to improve the withstand voltage of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W2, or the inside of the waveguide is maintained in a vacuum state. In such a usage mode, the electron tube 200 of the present embodiment connects the inside of the waveguide W2 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed on the outer side surface of the anode cylinder structure 1. Therefore, the inside of the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or maintained in a vacuum state. As a result, it is possible to prevent discharges between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, etc., and high withstand voltage of the input part can be achieved. In addition, in the present embodiment, a magnet 13a is arranged inside the shielding case 9, but it does not affect the high withstand voltage.

[0042] (Embodiment 3)

[0043] Next, Embodiment 3 of the electron tube of the present invention will be described. Figure 3 It is a cross-sectional schematic view for explaining Embodiment 3 of the electron tube of the present invention, and is a cross-sectional schematic view of the anode cylinder 2 in the tube axis direction. As Figure 3 shown, the electron tube 300 of the present embodiment is configured such that a waveguide W3 is joined to the output part of the magnetron M3. The magnetron M3 is the same as the magnetron M1 described in the above Embodiment 1, and a cathode 3 and anode plates 4 are arranged inside the anode cylinder 2 formed inside the rectangular anode cylinder structure 1. Hereinafter, the structures of the input part, output part, and communication hole 12 of the magnetron M3 will be mainly described in detail.

[0044] Figure 3 As shown, the electron tube 300 of the present embodiment is configured such that the input part from which the cathode lead 5 of the magnetron M3 is led out is arranged in a direction perpendicular to the tube axis direction of the anode cylinder 2, and the output part that arranges the antenna 6 and emits microwaves to the outside is arranged in the tube axis direction of the anode cylinder 2. In addition, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the E plane of the rectangular waveguide.

[0045] A pair of annular magnets 13a and 13b and a magnetic yoke (not shown) are arranged on both side surfaces of the anode cylinder structure 1 at both ends in the tube axis direction of the anode cylinder 2, and they constitute a magnetic circuit. The magnetic forces of the magnets 13a and 13b of this magnetic circuit are respectively applied to the action space between the front ends of the cathode 3 and the anode plates 4 through the pole pieces 14a and 14b.

[0046] Figure 3The cathode 3 shown has the same support structure as the cathode 3 described in the above-described Embodiment 1. That is, the two ends are supported by the cathode leads 5 in a direction perpendicular to the central axis of the cathode 3, and the two cathode leads 5 are led out to the input portion. The side surface of the anode cylindrical structure 1 from which the cathode leads 5 are led out becomes the "outer side surface of the anode cylindrical structure on the input portion side". In addition, the antenna 6 covered by the antenna cover 7 protrudes, and the side surface of the anode cylindrical structure 1 to which the waveguide W3 is joined becomes the "outer side surface of the anode cylindrical structure on the output portion side".

[0047] As Figure 3 shown, the cathode leads 5 connected to the cathode 3 are fixed to the anode cylindrical structure 1 by the insulating members 8. In addition, the anode cylindrical structure 1 is sealed by the insulating members 8, and the cathode leads 5 are exposed from the vacuum container including the anode cylinder 2. In order to prevent discharge or the like between the cathode leads 5 exposed from the insulating members 8 and the anode cylindrical structure 1, in the electron tube 300 of the present embodiment, the shielding case 9 is also hermetically joined to the outer side surface of the anode cylindrical structure 1 on the input portion side so as to surround a part of the cathode leads 5 exposed from the inside of the vacuum container. By configuring in this way, it is possible to surround a part of the cathode leads 5 and a part of the anode cylindrical structure 1 where discharge or the like is likely to occur originally by the shielding case 9. Further, the anode cylindrical structure 1 is provided with a communication hole 12 having a first opening 10 that opens in the region surrounded by the shielding case 9 and a second opening 11 that opens in the waveguide W3. In addition, the second opening 11 is configured to open in the waveguide W3 by being disposed in the through hole 15 formed in the E-plane of the waveguide W3.

[0048] Figure 3The electron tube 300 of the present embodiment shown is configured such that the input portion where the cathode lead 5 of the magnetron M3 is led out is arranged in a direction perpendicular to the tube axis direction of the anode cylinder 2. Further, it is configured such that the output portion where the antenna 6 is arranged and microwaves are emitted to the outside is arranged along the tube axis direction of the anode cylinder 2, and the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the E-plane of the rectangular waveguide. Therefore, the communication hole 12 is configured such that the first hole portion 12a having the first opening 10 and the second hole portion 12b having the second opening 11 are directly connected. The communication hole 12 has the first opening 10 that opens in the region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure body 1 on the input portion side and the second opening 11 that opens in the waveguide W3 via the through hole 15 formed in the waveguide W3 on the outer side surface of the anode cylinder structure body 1 on the output portion side. The communication hole 12 configured in this way can be easily formed by forming the linear first hole portion 12a from the outer side surface of the anode cylinder structure body 1 on the input portion side and then forming the linear second hole portion 12b from the outer side surface of the anode cylinder structure body 1 on the output portion side. In the present embodiment, it is necessary to form a through hole for inserting the output portion of the magnetron M3 and a through hole 15 for opening the second opening 11 in the waveguide W3, but these through holes can be easily formed in the normal manufacturing process of the waveguide. In addition, the communication hole 12 can be provided using only a relatively small area of the anode cylinder structure body 1. Therefore, when the communication hole 12 is provided, other structures such as the cooling water passage provided in the anode cylinder structure body 1 do not become a problem.

[0049] Also in the electron tube 300 of the present embodiment that can be used as an oscillation source of microwaves, in order to improve the withstand voltage of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W3, or the inside of the waveguide is maintained in a vacuum state. In such a usage mode, the electron tube 300 of the present embodiment connects the inside of the waveguide W3 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed on the outer side surface of the anode cylinder structure body 1. Therefore, the inside of the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or maintained in a vacuum state. As a result, it is possible to prevent discharges between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure body 1, etc., and high withstand voltage of the input portion can be achieved.

[0050] (Embodiment 4)

[0051] Next, Embodiment 4 of the electron tube of the present invention will be described. Figure 4 It is a cross-sectional schematic view for explaining Embodiment 4 of the electron tube of the present invention and is a cross-sectional view of the anode cylinder 2 along the tube axis direction. As Figure 4As shown, the electron tube 400 of the present embodiment is configured such that a waveguide W4 is joined to the output portion of the magnetron M4. The magnetron M4 is the same as the magnetron M1 described in the above-described Embodiment 1, and a cathode 3 and anode vanes 4 are disposed in an anode cylinder 2 formed inside a rectangular anode cylinder structure 1. Hereinafter, the structures of the input portion, output portion, and communication hole 12 of the magnetron M4 will be mainly described in detail.

[0052] Figure 4 In the electron tube 400 of the present embodiment shown, the input portion from which the cathode lead 5 of the magnetron M4 is led out and the output portion where an antenna 6 is disposed and microwaves are emitted to the outside are arranged in the tube axis direction of the anode cylinder 2 with the anode cylinder 2 therebetween. In addition, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the E-plane of the rectangular waveguide.

[0053] A pair of annular magnets 13a and 13b and a yoke (not shown) are disposed on both side surfaces of the anode cylinder structure 1 at both ends in the tube axis direction of the anode cylinder 2, and they constitute a magnetic circuit. The magnetic forces of the magnets 13a and 13b of this magnetic circuit are applied to the action space between the front ends of the cathode 3 and the anode vanes 4 through the pole pieces 14a and 14b, respectively.

[0054] Figure 4 The cathode 3 shown is configured in the same manner as the support structure of the cathode 3 described in the above-described Embodiment 2, and is configured to be supported from the central axis direction of the cathode 3 by the cathode lead 5, and the cathode lead 5 is led out to the input portion. The side surface of the anode cylinder structure 1 from which the cathode lead 5 is led out becomes the "outer side surface of the anode cylinder structure on the input portion side". In addition, the antenna 6 covered by the antenna cover 7 protrudes, and the side surface of the anode cylinder structure 1 to which the waveguide W4 is joined becomes the "outer side surface of the anode cylinder structure on the output portion side".

[0055] As Figure 4 shown, the cathode lead 5 connected to the cathode 3 is fixed to the anode cylinder structure 1 by an insulating member 8. In addition, the anode cylinder structure 1 is sealed by the insulating member 8, and the cathode lead 5 is exposed from the vacuum vessel including the anode cylinder 2. In order to prevent discharge or the like between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, in the electron tube 400 of the present embodiment, the shielding case 9 is also hermetically joined to the outer side surface of the anode cylinder structure 1 on the input portion side so as to surround a part of the cathode lead 5 exposed from the vacuum vessel. By configuring in this way, it is possible to surround a part of the cathode lead 5 and a part of the anode cylinder structure 1 that are liable to generate discharge or the like by the shielding case 9. Further, the anode cylinder structure 1 is provided with a communication hole 12 having a first opening 10 that opens in the region surrounded by the shielding case 9 and a second opening 11 that opens in the waveguide W4. In addition, the second opening 11 is configured to open in the waveguide W4 by being disposed in a through hole 15 formed in the E-plane of the waveguide W4.

[0056] Figure 4 The electron tube 400 of the present embodiment shown is configured such that the input section from which the cathode lead 5 of the magnetron M4 is led out and the output section where the antenna 6 is disposed and microwaves are transmitted to the outside are arranged in the tube axis direction of the anode cylinder 2 with the anode cylinder 2 interposed therebetween. Further, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the E-plane of the rectangular waveguide. Therefore, it is configured to include a communication hole 12 which has a first opening 10 that opens in a region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input section side and a second opening 11 that opens in the waveguide W4 via a through hole 15 formed in the waveguide W4 on the outer side surface of the anode cylinder structure 1 on the output section side. The communication hole 12 configured in this way can be easily formed by forming a linear through hole by a single machining from the outer side surface of the anode cylinder structure 1 on the input section side or the output section side, and the workability is good. In addition, the formation position of the through hole can be easily selected. In the present embodiment, it is necessary to form a through hole for inserting the output section of the magnetron M4 and a through hole 15 for opening the second opening 11 in the waveguide W4, and these through holes can be easily formed in the normal manufacturing process of the waveguide. In addition, the communication hole 12 can be provided using only a very small area of the anode cylinder structure 1. Therefore, other structures such as the cooling water passage do not cause problems.

[0057] Also in the electron tube 400 of the present embodiment that can be used as an oscillation source of microwaves, in order to improve the withstand voltage of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W4, or the inside of the waveguide is maintained in a vacuum state. In such a usage mode, the electron tube 400 of the present embodiment connects the inside of the waveguide W4 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed on the outer side surface of the anode cylinder structure 1. Therefore, the inside of the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or maintained in a vacuum state. As a result, it is possible to prevent discharges between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, etc., and high withstand voltage of the input section can be achieved. In addition, in the present embodiment, a magnet 13a is disposed inside the shielding case 9, but it does not affect the high withstand voltage.

[0058] (Embodiment 5)

[0059] Next, Embodiment 5 of the electron tube of the present invention will be described. Figure 5 It is a cross-sectional schematic view for explaining Embodiment 5 of the electron tube of the present invention, and is a cross-sectional view perpendicular to the tube axis direction of the anode cylinder 2. As Figure 5As shown, the electron tube 500 of the present embodiment is configured such that a waveguide W5 is joined to the output portion of the magnetron M5. The magnetron M5 is the same as the magnetron M1 described in the above-described Embodiment 1, and a cathode 3 and anode vanes 4 are disposed in an anode cylinder 2 formed inside a rectangular anode cylinder structure 1. Further, a shielding case 9 is hermetically joined to the outer side surface of the anode cylinder structure 1 on the input portion side so as to surround a part of the cathode lead 5 exposed from the vacuum container. Further, in the present embodiment, a cooling water passage 16 through which cooling water passes is disposed in the anode cylinder structure 1 in the axial direction of the anode cylinder 2. Hereinafter, the structures of the input portion, output portion, and communication hole 12 of the magnetron M5 will be mainly described in detail.

[0060] Figure 5 As shown, the electron tube 500 of the present embodiment is configured such that the input portion from which the cathode lead 5 of the magnetron M5 is led out and the output portion where an antenna 6 is disposed and microwaves are emitted to the outside are disposed in a direction perpendicular to the axial direction of the anode cylinder 2 with the anode cylinder 2 interposed therebetween. Further, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the end surface of the circular waveguide or the E-plane of the rectangular waveguide. In the present embodiment, since the cooling water passage 16 is disposed in the anode cylinder structure 1, it is not possible to form Figure 1 the communication hole 12 having the structure in which the first hole portion 12a and the second hole portion 12b described in are directly connected.

[0061] Therefore, the communication hole 12 is configured such that a first hole portion 12a having a first opening 10 and a second hole portion 12b having a second opening 11 are connected via a third hole portion 12c, and the communication hole 12 has the first opening 10 that opens in a region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input portion side and the second opening 11 that opens in the waveguide W5 on the outer side surface of the anode cylinder structure 1 on the output portion side. Figure 6 is a partial enlarged view of the joint portion of the third hole portion 12c and the second hole portion 12b that constitute the communication hole 12 formed in the anode cylinder structure 1. As Figure 5 and Figure 6 shown, a recess 17 extending in a direction perpendicular to the axial direction of the anode cylinder 2 is formed on the outer side surface of the anode cylinder structure 1, and the third hole portion 12c is formed by covering the opening of the recess 17 with a cover portion 18. The recess inner opening 19 opens in the recess 17. The hole portion having the recess inner opening 19 and the second opening 11 becomes the second hole portion 12b. Further, although in Figure 6Although not shown, other inner openings 19 of the recesses are formed in the recess 17. The hole portion having the inner opening 19 of the recess and the first opening 10 becomes the first hole portion 12a. A recess 17 is formed on the outer side surface of the anode cylinder structure 1, and a linear first hole portion 12a is formed in such a manner that the inner opening 19 of the recess is formed from the outer side surface of the anode cylinder structure 1 on the input portion side to the recess 17. Further, a linear second hole portion 12b is formed in such a manner that the inner opening 19 of the recess is formed from the outer side surface of the anode cylinder structure 1 on the output portion side to the recess 17. By covering the opening of the recess 17 with the cover portion 18, the communication hole 12 composed of the first to third hole portions 12a to 12c can be easily formed. The cover portion 18 can be formed either before or after the formation of the first hole portion 12a or the like.

[0062] Also in the electron tube 500 of the present embodiment that can be used as an oscillation source of microwaves, in order to improve the electric breakdown strength of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W5, or the inside of the waveguide is maintained in a vacuum state. In such a usage mode, the electron tube 500 of the present embodiment connects the inside of the waveguide W5 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed with respect to the anode cylinder structure 1. Therefore, the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or maintained in a vacuum state. As a result, it is possible to prevent discharge between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, and high withstand voltage of the input portion can be achieved. Further, in the present embodiment, the third hole portion 12c is configured to be covered with the cover portion 18, but the cover portion 18 is joined to the anode cylinder structure 1 with a joining strength that can be sealed under the pressure of the air or gas filled in the shielding case 9 and the waveguide including the waveguide W5 or in a vacuum state.

[0063] (Embodiment 6)

[0064] Next, Embodiment 6 of the electron tube of the present invention will be described. Figure 7 It is a cross-sectional schematic view for explaining Embodiment 6 of the electron tube of the present invention, and is a cross-sectional view perpendicular to the tube axis direction of the anode cylinder. As Figure 6 shown, the electron tube 600 of the present embodiment is configured such that a waveguide W6 is joined to the output portion of the magnetron M6. Figure 7The magnetron M6 shown is the same as the magnetron M1 described in the above-described Embodiment 1. The cathode 3 and the anode piece 4 are arranged in the anode cylinder 2 formed inside the rectangular anode cylinder structure 1. In addition, the shielding case 9 is hermetically joined to the outer side surface of the anode cylinder structure 1 on the input unit side so as to surround a part of the cathode lead 5 exposed from the vacuum container. Further, similar to the above-described Embodiment 5, a cooling water passage 16 through which cooling water passes is arranged in the anode cylinder structure 1 in the tube axis direction of the anode cylinder 2. Hereinafter, the structures of the input unit, the output unit, and the communication hole 12 of the magnetron M6 will be mainly described in detail.

[0065] Figure 7 The electron tube 600 of the present embodiment shown is configured such that the input unit from which the cathode lead 5 of the magnetron M6 is led out and the output unit on which the antenna 6 is arranged and which emits microwaves to the outside are arranged in a direction perpendicular to the tube axis direction of the anode cylinder 2 with the anode cylinder 2 interposed therebetween. In addition, it is configured such that the antenna 6 covered by the antenna cover 7 is inserted into the waveguide from the end face of the circular waveguide or the E-plane of the rectangular waveguide. In the present embodiment, since the cooling water passage 16 is arranged in the anode cylinder structure 1, it is not possible to form Figure 1 the communication hole 12 having the structure in which the first hole portion 12a and the second hole portion 12b described in are directly connected.

[0066] Therefore, the communication hole 12 is configured such that the first hole portion 12a having the first opening 10 and the second hole portion 12b having the second opening 11 are connected via the fourth hole portion 12d. The communication hole 12 has the first opening 10 that opens in the region surrounded by the shielding case 9 on the outer side surface of the anode cylinder structure 1 on the input unit side and the second opening 11 that opens in the waveguide W6 on the outer side surface of the anode cylinder structure 1 on the output unit side. Figure 8 is a partial enlarged view of the joint portion of the fourth hole portion 12d and the second hole portion 12b that constitute the communication hole 12 formed in the anode cylinder structure 1. As Figure 7 and Figure 8 shown, a through hole 20 extending in a direction perpendicular to the tube axis direction of the anode cylinder 2 is formed near the surface of the anode cylinder structure 1, and the fourth hole portion 12d is constituted by blocking both ends of the through hole 20 with the lid portion 21. The through hole inner opening 22 opens in the through hole 20. The hole portion having the through hole inner opening 22 and having the second opening 11 becomes the second hole portion 12b. In addition, although in Figure 8Although not shown in the figure, other through-hole inner openings 22 are formed in the through-hole 20 at the through-hole inner opening 22. The hole portion having the through-hole inner opening 22 and the first opening 10 becomes the first hole portion 12a. The through-hole 20 is formed near the surface of the anode cylinder structure 1, and the linear first hole portion 12a is formed in such a manner that the through-hole inner opening 22 is formed from the outer side surface of the anode cylinder structure 1 on the input portion side to the through-hole 20. Further, the linear second hole portion 12b is formed in such a manner that the through-hole inner opening 22 is formed from the outer side surface of the anode cylinder structure 1 on the output portion side to the through-hole 20. The openings at both ends of the through-hole 20 are blocked by the cover portion 21, whereby the communication hole 12 composed of the first hole portion 12a, the second hole portion 12b, and the fourth hole portion 12d can be easily formed. The formation of the cover portion 21 can be performed either before or after the formation of the first hole portion 12a and the like.

[0067] Also in the electron tube 600 of the present embodiment that can be used as an oscillation source of microwaves, in order to improve the withstand voltage of the waveguide for transmitting high-power microwaves, for example, pressurized dry air or sulfur hexafluoride gas with high insulation performance is filled in the waveguide including the waveguide W6, or the inside of the waveguide is maintained in a vacuum state. In such a usage mode, the electron tube 600 of the present embodiment connects the inside of the waveguide W6 and the inside of the shielding case 9 through the communication hole 12, and the shielding case 9 is sealed in the anode cylinder structure 1. Therefore, the inside of the shielding case 9 is also filled with pressurized dry air or sulfur hexafluoride gas with high insulation performance, or maintained in a vacuum state. As a result, it is possible to prevent discharge between the cathode lead 5 exposed from the insulating member 8 and the anode cylinder structure 1, and it is possible to achieve high withstand voltage at the input portion. Further, in the present embodiment, the fourth hole portion 12d is configured to be blocked by the cover portion 21, but the joining of the cover portion 21 to the anode cylinder structure 1 is configured to have a joining strength such that it can be sealed under the pressure of the air or gas filled in the shielding case 9 and the waveguide including the waveguide W6, or in a vacuum state.

[0068] As described above, since the electron tubes 100 to 600 of the present embodiment do not use components that deteriorate due to high temperature, there is no problem even if the anode cylinder structure 1, the shielding case 9, etc. become high temperature. Further, even if the gas in the shielding case 9 thermally expands, since the inside of the shielding case 9 communicates with the relatively large-volume waveguide W2 etc. through the communication hole 12, the pressure inside only the shielding case 9 does not increase, and the joining strength between the shielding case 9 and the anode cylinder structure 1 and the joining strength between the cover portion 21 and the anode cylinder structure 1 or the joining strength between the cover portion 21 and the anode cylinder structure 1 do not deteriorate.

[0069] Therefore, the electron tubes 100 to 600 of the present embodiment do not have a complex structure, can prevent discharges in the shielding case 9, etc., can apply a high input voltage, and can achieve high power of the electron tube. In addition, it can also be used on high ground where discharges are likely to occur.

[0070] The embodiments of the electron tube of the present invention have been described above. Of course, the present invention is not limited to the above embodiments. For example, the connection structure between the magnetron and the waveguide, the arrangement of the input part and the output part of the magnetron, etc. can be appropriately changed. As long as the communication hole 12 has a structure with at least a first opening 10 opening in the region surrounded by the shielding case 9 and a second opening 11 opening in the waveguide, it can be appropriately changed. The anode cylinder structure 1 can be configured to include a part that does not form an anode, such as a spacer. In addition, as long as the anode cylinder structure 1 can be hermetically joined to the shielding case 9 and the waveguide, it is not limited to a rectangle. The shapes of the communication hole 12, the through holes 15 and 20 only need to be shapes through which air and gas can pass. The shape of the shielding case 9 can also be appropriately changed.

[0071] (Summary)

[0072] (1) An embodiment of the electron tube of the present invention is configured as an electron tube including: a cathode that emits thermoelectrons; an anode in which a plurality of anode plates are arranged in an anode cylinder inside the anode cylinder structure so as to surround the cathode, and a cavity resonator is formed between the anode plates; an input part that leads out a cathode lead for applying an input voltage to the cathode; an output part that emits microwaves excited by the cavity resonator to the outside; and a waveguide that transmits the microwaves emitted from the output part, wherein a hermetically sealable shielding case that surrounds a part of the cathode lead is joined to the outer side surface of the anode cylinder structure on the input part side, the hermetically sealable waveguide is joined to the outer side surface of the anode cylinder structure on the output part side, and the anode cylinder structure has a communication hole that has a first opening opening in the region surrounded by the shielding case and a second opening opening in the waveguide.

[0073] According to the electron tube of the embodiment of (1) above, since it is configured to have a communication hole that has openings in the region surrounded by the shielding case covering a part of the cathode lead and in the waveguide that transmits the microwaves emitted from the output part, and the cathode lead applies an input voltage to the cathode, the inside of the waveguide that transmits high-power microwaves is in communication with the inside of the shielding case, the withstand voltage of the input part is improved, and a high-power electron tube can be provided.

[0074] (2) According to another embodiment, in the electron tube of (1) above, the second opening is arranged in a through hole formed in the wall surface of the waveguide.

[0075] (3) According to another embodiment, in the electron tube of (1) or (2) above, the communication hole is formed by directly connecting a first hole portion having the first opening and a second hole portion having the second opening.

[0076] (4) According to another embodiment, in the electron tube of (1) or (2) above, the anode cylinder structure has a third hole portion, which is composed of a concave portion formed in the anode cylinder structure and a lid portion covering the opening of the concave portion, and the communication hole is formed by connecting a first hole portion having the first opening and a second hole portion having the second opening via the third hole portion.

[0077] (5) According to another embodiment, in the electron tube of (1) or (2) above, the anode cylinder structure has a fourth hole portion, which is composed of a through hole penetrating the anode cylinder structure and a lid portion covering the opening of the through hole, and the communication hole is formed by connecting a first hole portion having the first opening and a second hole portion having the second opening via the fourth hole portion.

[0078] (6) According to another embodiment, in the electron tube of (1) or (2) above, the shielding case communicated with the waveguide and the communication hole is sealed, and the inside of the waveguide and the inside of the shielding case are configured to have equal pressure and / or atmosphere.

[0079] Description of Reference Numerals

[0080] 100 - 600 Electron tubes

[0081] M1 - M6 Magnetrons

[0082] W1 - W6 Waveguides

[0083] 1 Anode cylinder structure

[0084] 2 Anode cylinder

[0085] 3 Cathode

[0086] 4 Anode plate

[0087] 5 Cathode lead

[0088] 6 Antenna

[0089] 7 Antenna cover

[0090] 8 Insulating member

[0091] 9 Shielding case

[0092] 10 First opening

[0093] 11 Second opening

[0094] 12 communication holes

[0095] 12a to 12d first to fourth hole parts

[0096] 13a, 13b magnets

[0097] 14a, 14b pole pieces

[0098] 15, 20 through holes

[0099] 16 cooling water passages

[0100] 17 recesses

[0101] 18, 21 cover parts

[0102] 19 inner openings of the recesses

[0103] 22 inner openings of the through holes.

Claims

1. An electron tube, the electron tube comprising: A cathode that emits thermoelectrons; An anode, in which a plurality of anode plates are arranged in an anode cylinder inside an anode cylinder structure so as to surround the cathode, and a cavity resonator is formed between the anode plates; An input section that leads out a cathode lead for applying an input voltage to the cathode; An output section that emits microwaves excited by the cavity resonator to the outside; And A waveguide that transmits the microwaves emitted from the output section, wherein A hermetically sealable shielding case that surrounds a part of the cathode lead is joined to the outer side surface of the anode cylinder structure on the input section side, The hermetically sealable waveguide is joined to the outer side surface of the anode cylinder structure on the output section side, The anode cylinder structure is provided with a communication hole that has a first opening that opens in a region surrounded by the shielding case and a second opening that opens inside the waveguide.

2. The electron tube according to claim 1, wherein The second opening is arranged inside a through hole formed in the wall surface of the waveguide.

3. The electron tube according to claim 1 or 2, wherein The communication hole is formed by directly connecting a first hole portion having the first opening and a second hole portion having the second opening.

4. The electron tube according to claim 1 or 2, wherein The anode cylinder structure has a third hole portion that is composed of a recess formed in the anode cylinder structure and a lid portion that covers an opening of the recess, The communication hole is formed by connecting a first hole portion having the first opening and a second hole portion having the second opening via the third hole portion.

5. The electron tube according to claim 1 or 2, wherein The anode cylinder structure has a fourth hole portion that is composed of a through hole that penetrates the anode cylinder structure and a lid portion that covers an opening of the through hole, The communication hole is formed by connecting a first hole portion having the first opening and a second hole portion having the second opening via the fourth hole portion.

6. The electron tube according to claim 1 or 2, wherein The shielding case that is communicated via the waveguide and the communication hole is hermetically sealed, and the inside of the waveguide and the inside of the shielding case have equal pressure and / or atmosphere.

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