JP2018113503A - High frequency transmission window body structure and high frequency input coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency transmission window body structure in which a high frequency transmission window is made unlikely to crack.SOLUTION: A high frequency transmission window body structure 17 comprises: a high frequency transmission window 40; an outer sleeve 42 which is brazed and bonded to an outer periphery of the high frequency transmission window 40; and an inner sleeve 41 which is brazed and bonded to an inner periphery of the high frequency transmission window 40. The outer sleeve 42 includes: a cylindrical sleeve part 48; and sleeve fitting parts 49 that are provided in both ends of the sleeve part 48 in an axial direction. In the sleeve part 48, a groove portion 50 is provided on an outer peripheral surface of an axial intermediate part that is separated from the sleeve fitting parts 49, and a thin portion 51 is provided by resulting from the groove portion 50. The thin portion 51 is brazed and bonded to the outer periphery of the high frequency transmission window 40.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a high-frequency transmission window structure that maintains airtightness and transmits high-frequency waves (microwaves), and a high-frequency input coupler that uses the high-frequency transmission window structure.

  In a charged particle (electron, ion, proton) accelerator, when a high-frequency wave emitted from a high-frequency amplifier such as a klystron is incident on the acceleration cavity, a structure that can provide a good coupling to the acceleration cavity A high frequency input coupler (coupler) is used.

  The high-frequency input coupler includes a high-frequency transmission window structure for allowing a high frequency incident from the atmosphere side to enter an acceleration cavity maintained in a high vacuum.

  The high-frequency transmission window structure includes a high-frequency transmission window that allows high-frequency transmission while maintaining airtightness, and an outer sleeve and an inner sleeve that are joined to the outer periphery and inner periphery of the high-frequency transmission window by brazing to form a high-frequency transmission path. .

  A ceramic such as alumina is used for the high-frequency transmission window, and a metal such as copper is used for each sleeve. The joint surface of each high-frequency transmission window with each sleeve has a metallized layer, and each sleeve is joined by brazing via this metallized layer. Thereby, airtightness is maintained before and after the high-frequency transmission window.

  By the way, the high-frequency transmission window structure is exposed to a high temperature of 1000 ° C. or higher when assembled by brazing, and further, the high-frequency transmission window structure is heated to a high temperature of 700 ° C. or higher when each component of the high-frequency window structure and high-frequency input coupler is assembled by brazing. Exposed. At that time, since the thermal expansion coefficient of the material differs between the high frequency transmission window and each sleeve, the high frequency transmission window is pulled in the vicinity of the outer sleeve and the joint surface of the high frequency transmission window when the temperature is increased or decreased during brazing. Stress is generated. As a result, cracks may occur in the high frequency transmission window starting from the end of the joint surface of the high frequency transmission window with the outer sleeve. When this crack penetrates the high-frequency transmission window, there is a problem that the high-frequency input coupler cannot be kept airtight.

Japanese Patent Laying-Open No. 2015-141848

  The problem to be solved by the present invention is to provide a high-frequency transmission window structure and a high-frequency input coupler in which cracks are unlikely to occur in the high-frequency transmission window.

  The high-frequency transmission window structure of this embodiment includes a high-frequency transmission window, an outer sleeve that is brazed to the outer periphery of the high-frequency transmission window, and an inner sleeve that is brazed to the inner periphery of the high-frequency transmission window. The outer sleeve has a cylindrical sleeve portion and sleeve mounting portions provided at both axial ends of the sleeve portion. In the sleeve portion, a groove portion is provided on the outer peripheral surface of the intermediate portion in the axial direction separated from the sleeve mounting portion, and a thin portion is provided by the groove portion. The thin part is brazed and joined to the outer periphery of the high-frequency transmission window.

It is sectional drawing of the high frequency transmission window structure which shows one Embodiment. It is sectional drawing of the high frequency input coupler using a high frequency transmission window structure same as the above.

  Hereinafter, an embodiment will be described with reference to FIGS. 1 and 2.

  The high frequency input coupler 10 couples between the waveguide 11 that transmits a high frequency (microwave) radiated from a high frequency amplifier such as a klystron and the acceleration cavity 13 of the accelerator 12, and Is used to isolate the high pressure in the accelerating cavity 13 and the high frequency in the accelerating cavity 13.

  The high-frequency input coupler 10 includes a coupler main body 16 and a high-frequency transmission window structure 17 incorporated in the coupler main body 16.

  The coupler main body 16 has a columnar inner conductor 20 and a cylindrical outer conductor 21 that are arranged coaxially. High frequency is transmitted between the inner conductor 20 and the outer conductor 21.

  The inner conductor 20 has an atmosphere-side inner choke 23 and a vacuum-side inner choke 24 to which the inside of the high-frequency transmission window structure 17 is joined, and is disposed so as to protrude from the vacuum-side inner choke 24 to the acceleration cavity 13 of the accelerator 12. The antenna unit 25 is provided.

  The outer conductor 21 has an atmosphere-side outer choke 27 and a vacuum-side outer choke 28 to which the outside of the high-frequency transmission window structure 17 is joined, and an outer peripheral portion of the atmosphere-side outer choke 27 and an outer peripheral portion of the vacuum-side outer choke 28. And a connecting cylinder 29 joined to be connected to each other. An atmosphere side flange 30 to which the waveguide 11 is attached is joined to the atmosphere side outer choke 27, and a vacuum side flange 31 is joined to the vacuum side outer choke 28. An outer peripheral cylinder 32 is attached to the vacuum flange 31, and the outer peripheral cylinder 32 is attached to the accelerator 12.

  The high-frequency input coupler 10 is assembled by assembling the high-frequency transmission window structure 17 and then joining the components together with the high-frequency transmission window structure 17 by brazing.

  The high-frequency transmission window structure 17 includes a high-frequency transmission window 40 that is airtight and transmits high frequencies, an inner sleeve 41 and an outer sleeve 42 that constitute a transmission path, and a portion to which the high-frequency transmission window 40 of the inner sleeve 41 is brazed. And a metal wire 44 wound around the outer peripheral side of the portion where the high-frequency transmission window 40 of the outer sleeve 42 is brazed, and an outer sleeve. 42 is provided with an atmosphere side outer choke 27 joined to 42 by brazing.

  As a material of the high-frequency transmission window 40, for example, ceramic such as alumina is used. The high-frequency transmission window 40 is formed in a disc shape (annular shape) having a circular hole 46 in the center. Then, the inner sleeve 41 is inserted into the hole 46 of the high-frequency transmission window 40, the high-frequency transmission window 40 is inserted into the outer sleeve 42, and the joint surface between the high-frequency transmission window 40 and the inner sleeve 41 and the outer sleeve 42 is the brazing material. It is airtightly joined by brazing.

  As the material of the inner sleeve 41 and the outer sleeve 42, for example, a metal such as copper is used. The inner sleeve 41 and the outer sleeve 42 are formed in a cylindrical shape so as to be arranged coaxially.

  The outer sleeve 42 has a cylindrical sleeve portion 48 and sleeve mounting portions 49 provided at both axial ends of the sleeve portion 48. The sleeve mounting portion 49 on one end side is joined and attached to the atmosphere side outer choke 27 by brazing, and the sleeve attaching portion 49 on the other end side is joined and attached to the vacuum side outer choke 28 by brazing.

  The sleeve portion 48 of the outer sleeve 42 is provided with a groove portion 50 on the outer peripheral surface of the intermediate portion in the axial direction of the sleeve portion 48 that is separated from the sleeve mounting portions 49 at both ends. A thin portion 51 having a small thickness is provided. That is, the sleeve portion 48 includes a thin portion 51 provided in the axially intermediate portion and a thick portion 52 in which the sleeve portions 48 provided on both axial sides of the thin portion 51 are thick. Sleeve attachment portions 49 are provided at both axial ends of the meat portion 52. For example, the axial length of the region where the groove portion 50 (thin portion 51) in the axial direction of the sleeve portion 48 is larger than the thickness dimension of the high-frequency transmission window 40, and the groove portion 50 (thin portion). 51) is smaller than the axial length of the region where the portion 51 is not provided (that is, the portion of the thick portion 52). The wire 44 is wound around the outer periphery of the thin portion 51 in the groove 50, and the thin portion 51 is joined to the outer periphery of the high-frequency transmission window 40 by brazing.

  The metal thin film 43 is made of, for example, a metal such as molybdenum having a smaller coefficient of thermal expansion than the copper inner sleeve 41, and brazed to the inner peripheral side of the portion where the high frequency transmission window 40 of the inner sleeve 41 is brazed. It is joined by.

  The wire 44 is made of, for example, a metal such as molybdenum having a smaller coefficient of thermal expansion than the copper outer sleeve 42, and a portion (a thin portion 51 in the groove 50) to which the high frequency transmission window 40 of the outer sleeve 42 is brazed. ). The number of windings of the wire 44 around the outer sleeve 42 is arbitrary.

  The high-frequency transmission window assembly 17 configured as described above is exposed to a high temperature of, for example, 1000 ° C. or more when assembled by brazing the high-frequency transmission window assembly 17 itself. When the parts of the vessel 10 are assembled by brazing, they are exposed to a high temperature of 700 ° C. or higher.

  At that time, since the thermal expansion coefficient of the material differs between the ceramic high-frequency transmission window 40 and the copper outer sleeve 42, the high-frequency transmission window 40 is joined to the outer sleeve 42 when the temperature rises or drops during brazing. A tensile stress is generated in the high-frequency transmission window 40 in the vicinity of the surface. As a result, cracks may occur toward the inside of the high frequency transmission window 40 starting from the end of the joint surface of the high frequency transmission window 40 with the outer sleeve 42.

  In the high frequency transmission window structure 17 of the present embodiment, the groove portion 50 is provided on the outer peripheral surface of the outer sleeve 42 to provide the thin portion 51 on the outer sleeve 42, and the high frequency transmission window 40 is brazed to the thin portion 51. Thereby, the tensile stress generated in the high frequency transmission window 40 during brazing can be reduced, and cracks can be hardly generated in the high frequency transmission window 40.

  In addition, since the groove portion 50 is provided on the outer peripheral surface of the outer sleeve 42, for example, the influence on the electric field generated when the groove portion 50 is provided on the inner peripheral surface of the outer sleeve 42 can be prevented.

  Furthermore, the axial length of the region where the groove portion 50 (thin portion 51) is provided in the axial direction of the sleeve portion 48 is the region where the groove portion 50 (thin portion 51) is not provided (that is, the thick portion 52). Therefore, the strength of the outer sleeve 42 can be ensured compared to the case where the entire sleeve portion 48 is made thicker than the thin portion 51, for example.

  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 High frequency input coupler
16 coupler body
17 High-frequency transmission window structure
20 Inner conductor
21 Outer conductor
40 High-frequency transmission window
41 inner sleeve
42 outer sleeve
48 Sleeve
49 Sleeve mounting
50 groove
51 Thin section

Claims (3)

A high-frequency transmission window;
An outer sleeve brazed to the outer periphery of the high-frequency transmission window;
An inner sleeve brazed to the inner periphery of the high-frequency transmission window,
The outer sleeve has a cylindrical sleeve portion and sleeve mounting portions provided at both axial end portions of the sleeve portion, and the sleeve portion has an outer peripheral surface of an axial intermediate portion separated from the sleeve mounting portion. The high-frequency transmission window structure is characterized in that a thin-wall portion is provided by the groove portion, and the thin-wall portion is brazed to the outer periphery of the high-frequency transmission window. 2. The high-frequency transmission window structure according to claim 1, wherein the outer sleeve has a region where the groove portion is provided in the axial direction of the sleeve portion smaller than a region where the groove portion is not provided. A coupler body having an inner conductor and an outer conductor;
2. The high-frequency input coupler according to claim 1, further comprising: the inner sleeve attached to the inner conductor, and the sleeve attaching portion of the outer sleeve attached to the outer conductor.

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