JP2015141777A - gyrotron collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gyrotron collector capable of preventing deformation.SOLUTION: A gyrotron collector 20 includes a collector body 24 and a reinforcement part 32. The collector body 24 is so formed so that one end in an axial direction is open and the other end is closed in a cylindrical shape. The reinforcement part 32 is stronger than the collector body 24 and is provided in an annular shape along a circumferential direction at a part of the collector body 24.

Description

  Embodiments described herein relate generally to a gyrotron collector that generates millimeter wave electromagnetic waves.

  Conventionally, as a means for heating and controlling plasma in nuclear fusion or the like, for example, a method using electromagnetic waves in the millimeter wave band is known. High-power gyrotrons are promising as oscillation sources for oscillating millimeter wave electromagnetic waves.

  The gyrotron oscillates by injecting a hollow swirling electron beam into a cavity resonator in a high magnetic field under vacuum. Oscillation causes the electron beam to lose some energy and be collected at the collector. Since the overall efficiency of the gyrotron is around 50%, for example, if the gyrotron has an output of 1 MW, 1 MW of energy is consumed even at the collector. The electron beam of the gyrotron is collected by the collector and converted into thermal energy. As a result, the collector becomes hot. In order to remove the heat of the collector, the periphery of the collector is covered with a cooling jacket, and cooling water is circulated between the collector and the cooling jacket for cooling.

  For the collector of a general gyrotron, oxygen-free copper having high conductivity and thermal conductivity and low outgassing into vacuum is used. However, the softening temperature of oxygen-free copper is slightly low, about 200 ° C., and a part of the collector may be deformed due to a decrease in the strength of the collector due to heat generation during high power operation of the gyrotron and the pressure of the cooling water applied to the collector. There is.

JP 2003-123658 A

  If the gyrotron collector is deformed, there is a concern of causing a vacuum leak in the collector.

  The problem to be solved by the present invention is to provide a gyrotron collector capable of preventing deformation.

  The collector of the gyrotron of this embodiment is provided in a cylindrical shape along a circumferential direction in a cylindrical collector body having one end opened in the axial direction and closed at the other end, and a part of the collector body, And a reinforcing part having higher strength than the collector body.

It is sectional drawing of the collector of the gyrotron which shows 1st Embodiment. It is a perspective view of a collector same as the above. It is a schematic sectional drawing of a gyrotron same as the above. It is sectional drawing of the collector of the gyrotron which shows 2nd Embodiment.

  Hereinafter, a first embodiment will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 3, the gyrotron 10 is made quasi-optically by a cavity resonator (cavity) 14 by an electron beam 13 emitted from an electron gun 12 provided at one end of the tube body 11 in the axial direction. An electromagnetic wave 15 that is a millimeter wave or microwave is generated. The generated electromagnetic wave 15 is converted into a parallel beam by the mode converter 16 and the transmission mirror system 17 (transmission mirrors 17a to 17d), reflected by the transmission mirror 17d toward the output window 18 of the output waveguide, and the gyro The output wave 19 is derived outside the TRON 10.

  The electron beam 13 after being used to generate the electromagnetic wave 15 is swept by a sweep (sweep) coil (not shown) and is captured by a collector 20 provided on the other end side in the axial direction of the tube body 11.

  The inside of the gyrotron 10 is in a vacuum state, and a magnetic field generator 21 made of, for example, a superconducting electromagnet is provided around the tube body 11 outside the cavity resonator 14.

  As shown in FIGS. 1 and 2, the collector 20 includes a cylindrical collector body 24 that is open at one end in the axial direction and closed at the other end.

  A flange 25 for joining to the tube body 11 is brazed to one end of the collector body 24. The flange 25 is made of, for example, a stainless material.

  A plurality of fins 26 project from the outer peripheral surface of the collector body 24 along the axial direction of the collector 20.

  The collector 20 of the output 1 MW class gyrotron 10 has an inner diameter of about 360 mm, but its length is 1 m or more. Therefore, the collector 20 is divided into a plurality of collector parts 27, 28, 29, and 30 in the axial direction, and these collector parts 27, 28, 29, and 30 are integrally assembled. Each of the collector parts 27, 28, 29, and 30 is cylindrical and has a plurality of fins 26 protruding from the outer peripheral surface thereof, and a closed part 31 is formed only in the collector part 30 at the tip. The collector parts 27, 28, 29, and 30 are concavo-convexly fitted and brazed and joined.

  The collector body 24, that is, the collector parts 27, 28, 29, and 30 are made of oxygen-free copper having high conductivity and thermal conductivity and low gas release into the vacuum.

  A cylindrical reinforcing portion 32 is integrally installed between the collector parts 28 and 29 in the center of the collector 20 in the axial direction. The replenishment part 32 is made of, for example, stainless steel having a higher softening temperature and higher strength than oxygen-free copper, which is the material of the collector body 24. The reinforcing portion 32 has a cylindrical shape, and a plurality of fins 33 that are continuous with the fins 26 of the collector body 24 project from the outer peripheral surface, and are formed in the same cross-sectional shape as the collector parts 27, 28, 29, and 30. The reinforcing portion 32 is assembled to the collector parts 28 and 29 by being unevenly fitted and brazed.

  Regarding the width in the axial direction of the reinforcing portion 32, the thermal conductivity of stainless steel is not as high as that of oxygen-free copper, so if the width is too large, it will affect the heat dissipation from the collector 20, while if the width is too small Since sufficient reinforcement performance of the collector 20 cannot be obtained, the optimum width is set in consideration of heat dissipation and strength.

  In the gyrotron 10 configured as described above, the electron beam collected by the collector 20 is converted into thermal energy, and the collector 20 becomes high temperature. In order to remove the heat of the collector 20, the periphery of the collector 20 is covered with a cooling jacket, and cooling is performed by circulating cooling water between the collector 20 and the cooling jacket. In normal use of the gyrotron 10, the temperature of the collector 20 rises to 200 ° C. to 300 ° C., and the cooling water pressure is applied to the collector 20 by about 10 kPa.

  Here, when the collector 20 is not provided with the reinforcing portion 32, the softening temperature of the oxygen-free copper, which is the material of the collector 20, is somewhat low, about 200 ° C. As a result, deformation that is recessed toward the center of the collector 20 tends to occur at the central portion of the collector 20 in the axial direction. If this deformation occurs, for example, in the vicinity of the junction between the collector parts 28 and 29, a vacuum leak of the collector 20 will occur.

  In the present embodiment, since the collector 20 includes the reinforcing portion 32, even if the strength decreases due to the temperature rise of the collector main body 24, the pressure of the cooling water is supported by the reinforcing portion 32 and deformation of the collector 20 can be prevented. . Thereby, the collector 20 can be used stably for a long period of time.

  Note that if you try to secure the strength by thickening a part of the collector body 24 to the outside, the cooling structure of the collector 20 will be complicated, and if you try to secure the strength by thickening the entire collector body 24, you will dissipate heat. Therefore, it is effective that the collector 20 includes the reinforcing portion 32.

  Next, FIG. 4 shows a second embodiment. In addition, the same code | symbol is used about the same structure as 1st Embodiment, and the description about the structure and effect is abbreviate | omitted.

  A cover portion 35 of oxygen-free copper, which is the same material as the collector main body 24 (collector parts 27, 28, 29, 30), is formed on the inner peripheral surface of the reinforcing portion 32.

  Conductivity inside the collector 20 is also made by using oxygen-free copper, which is the same material as the collector body 24 (collector parts 27, 28, 29, 30), on the inner peripheral surface of the reinforcing portion 32. In addition, the thermal conductivity can be increased, and the release of gas into the vacuum can be reduced.

  The reinforcing portion 32 is not limited to being provided at one location of the collector 20, and may be provided at a plurality of locations. For example, reinforcing portions 32 are provided between the collector parts 27, 28, 29, and 30, respectively.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 Gyrotron
20 collector
24 Collector body
27, 28, 29, 30 Collector parts
32 reinforcement
35 Cover

Claims (4)

A cylindrical collector body with one axial end open and the other closed;
A collector of a gyrotron comprising: a reinforcing portion provided in a cylindrical shape along a circumferential direction in a part of the collector main body, and having a strength higher than that of the collector main body. The gyrotron collector according to claim 1, wherein the reinforcing portion is provided in a central portion of the collector main body in the axial direction. The gyrotron collector according to claim 1, wherein the collector body has a plurality of collector parts divided into a plurality of parts in the axial direction, and a reinforcing portion is provided between the collector parts. The collector of the gyrotron according to any one of claims 1 to 3, wherein the reinforcing portion includes a cover portion made of the same material as the collector main body on an inner peripheral side facing the inside of the collector main body.

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