JP6845749B2 - High frequency transmission window structure and high frequency input coupler - Google Patents

Description

An embodiment of the present invention relates to a high-frequency transmission window structure having a high-frequency transmission window that transmits high frequencies and a high-frequency input coupler.

Conventionally, in a charged particle (electron, ion, proton) accelerator, when a high frequency emitted from a high frequency amplifier such as a klystron is incident on the accelerating cavity, it is possible to have a good coupling with the accelerating cavity. A high-frequency input coupler (coupler) having a structure is used.

The high-frequency input coupler includes a high-frequency transmission window structure for incidenting high-frequency waves incident from the atmosphere side into an accelerated cavity maintained in a high vacuum.

The high-frequency transmission window structure includes a high-frequency transmission window that transmits high frequencies while maintaining airtightness, an outer conductor sleeve and an inner conductor sleeve that serve as high-frequency transmission paths. The joint surfaces provided on the outer and inner circumferences of the high-frequency transmission window are brazed to the inner circumference of the outer conductor sleeve and the outer circumference of the inner conductor sleeve.

Ceramics such as alumina are used for the high-frequency transmission windows, and metals such as copper are used for each sleeve.

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 and each component of the high-frequency input coupler are exposed to a high temperature of 700 ° C. or higher when assembled by brazing. Be exposed. At that time, since the coefficient of thermal expansion of the material differs between the high-frequency transmission window and each sleeve, tensile stress is generated in the high-frequency transmission window when the temperature rises or falls during brazing. As a result, cracks may occur from the end of the joint surface of the high-frequency transmission window toward the inside of the high-frequency transmission window. If this crack penetrates the high-frequency transmission window, there is a problem that the airtightness of the high-frequency input coupler cannot be maintained.

JP-A-2015-141848

An object to be solved by the present invention is to provide a high frequency transmission window structure and a high frequency input coupler capable of preventing cracks from occurring in the high frequency transmission window.

The high-frequency transmission window structure of the present embodiment includes a high-frequency transmission window having a joint surface and a sleeve in which the joint surface of the high-frequency transmission window is brazed and joined. The sleeve is provided at a width smaller than the width of the joint surface of the high-frequency transmission window, and the central portion in the width direction of the joint surface is brazed to be joined, and the sleeve is provided along both sides of the joint portion and projects from both sides of the joint portion. The outer side portion in the width direction of the joint surface to be formed has a groove portion facing the opposite surface. The depth dimension of the groove portion is smaller than the width dimension of the outer portion in the width direction of the joint surface facing the groove portion.

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

Hereinafter, one embodiment will be described with reference to the drawings.

FIG. 2 shows a cross-sectional view of the high frequency input coupler 10.

The high-frequency input coupler 10 couples between the waveguide 11 that transmits high frequencies (microwaves) radiated from a high-frequency amplifier such as a klystron and the accelerating cavity 13 of the accelerator 12, and is inside the waveguide 11. It is used to isolate the atmospheric pressure and the high vacuum in the accelerating waveguide 13 and to inject high frequencies into the accelerating waveguide 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 body 16 has a cylindrical inner conductor 20 and a cylindrical outer conductor 21 arranged coaxially. High frequencies are transmitted between the inner conductor 20 and the outer conductor 21. The inner conductor 20 has an antenna portion 22 that is joined to the inside of the high-frequency transmission window structure 17 and is projected from the accelerator cylinder 13 of the accelerator 12. The outer conductor 21 is joined to the outside of the high-frequency transmission window structure 17 and is attached to the accelerator 12.

Further, the high-frequency transmission window structure 17 includes a high-frequency transmission window 30 that maintains airtightness and transmits high frequencies, and an inner conductor sleeve 31a and an outer conductor sleeve 31b as sleeves constituting a transmission line.

Ceramics such as alumina are used as the material of the high frequency transmission window 30. The high-frequency transmission window 30 is formed in a disk shape (annular ring) having a circular hole in the center.

A metal such as copper is used as the material of the inner conductor sleeve 31a and the outer conductor sleeve 31b. The inner conductor sleeve 31a and the outer conductor sleeve 31a are formed in a cylindrical shape and are coaxially arranged via the high frequency transmission window 30.

Then, the inner conductor sleeve 31a is inserted into the hole 33 of the high frequency transmission window 30, the high frequency transmission window 30 is inserted inside the outer conductor sleeve 31b, and the high frequency transmission window 30, the inner conductor sleeve 31a and the outer conductor sleeve 31b are separated. It is attached and joined. Further, the inner conductor sleeve 31a is brazed to the outer periphery of the inner conductor 20, and the outer conductor sleeve 31b is brazed to the end of the outer conductor 21.

Next, FIG. 1 shows a cross-sectional view of a part of the high-frequency transmission window structure 17.

Joint surfaces (window side joint surfaces) 35a and 35b are formed on the inner and outer circumferences of the high-frequency transmission window 30 to be brazed to the outer peripheral surface of the inner conductor sleeve 31a and the inner peripheral surface of the outer conductor sleeve 31b. Inclined surfaces 36a and 36b, which are diagonally cut chamfered portions, are formed at the corners on both sides of the inner circumference and the outer circumference of the high-frequency transmission window 30 in the width direction. Metallized layers are formed on the joint surfaces 35a and 35b, and brazing members 37a and 37b are provided on the metallized layers.

On the outer peripheral surface of the inner conductor sleeve 31a, a joint portion 39a for brazing and joining the joint surface 35a on the inner circumference of the high-frequency transmission window 30 is formed, and groove portions 40a are formed on both sides of the joint portion 39a. .. A joint portion 39b is formed on the inner peripheral surface of the outer conductor sleeve 31b to braze and join the joint surface 35b on the outer periphery of the high-frequency transmission window 30, and groove portions 40b are formed on both sides of the joint portion 39b. ..

The joint portions 39a and 39b are formed with sleep-side joint surfaces 41a and 41b to which the joint surfaces 35a and 35b of the high-frequency transmission window 30 are brazed and joined.

The groove portions 40a and 40b have side surfaces 42a and 42b on both sides in the groove width direction, and bottom surfaces 43a and 43b on the inner side of the groove. The side surfaces 42a and 42b are formed in an inclined shape so as to expand from the bottom surfaces 43a and 43b toward the opening side. The side surfaces of the joints 39a and 39b are composed of the side surfaces 42a and 42b of the grooves 40a and 40b, and the cross-sectional shape of the joints 39a and 39b is trapezoidal.

The width W1 of the joint portions 39a and 39b is smaller than the width W2 of the joint surfaces 35a and 35b of the high-frequency transmission window 30. The central portions 44a and 44b in the width direction of the joint surfaces 35a and 35b of the high-frequency transmission window 30 are brazed to the joints 39a and 39b. Therefore, the outer portions 45a and 45b in the width direction located on both sides of the central portions 44a and 44b in the width direction of the joint surfaces 35a and 35b of the high-frequency transmission window 30 are projected (exposed) from the joint portions 39a and 39b, and the groove portions 40a and 40a, It is arranged so as to face 40b.

The depth dimension D1 of the groove portions 40a and 40b is provided smaller than the width dimension W3 of the outer portions 45a and 45b in the width direction of the joint surfaces 35a and 35b facing the groove portions 40a and 40b.

Further, the brazing members 37a and 37b are interposed between the central portions 44a and 44b in the width direction of the joint surfaces 35a and 35b of the high-frequency transmission window 30 and the sleep-side joint surfaces 41a and 41b of the joint portions 39a and 39b. ing.

A part of the brazing filler metal 37a, 37b is formed between the outer portions 45a, 45b in the width direction of the joint surfaces 35a, 35b of the high-frequency transmission window 30 and the side surfaces 42a, 42b of the joint portions 39a, 39b, and the meniscus portions 47a, 47b. Is forming. The meniscus portions 47a and 47b are thin on the widthwise outer portions 45a and 45b of the joint surfaces 35a and 35b on the widthwise side 48a and 48b, and the widthwise outer portions 45a and 45b of the joint surfaces 35a and 35b are thin. The thickness gradually increases from the 48b side toward the side surfaces 42a and 42b of the joints 39a and 39b, and is joined to the entire surface of the side surfaces 42a and 42b of the joints 39a and 39b, reaching the bottom surfaces 43a and 43b of the grooves 40a and 40b. There is.

The high-frequency transmission window structure 17 configured in this way is exposed to a high temperature of, for example, 1000 degrees or more when the high-frequency transmission window structure 17 itself is assembled by brazing, and further, a high-frequency input coupling with the high-frequency transmission window structure 17 thereafter. When each part of the vessel 10 is assembled by brazing, it is exposed to a high temperature of 700 ° C. or higher.

At that time, since the coefficient of thermal expansion of the material differs between the ceramic high-frequency transmission window 30 and the copper inner conductor sleeve 31a and outer conductor sleeve 31b, the high-frequency transmission window 30 is used when the temperature rises or falls during brazing. Stress is likely to occur.

If the entire width direction of the joint surfaces 35a and 35b of the high-frequency transmission window 30 is brazed to the inner conductor sleeve 31a and the outer conductor sleeve 31b, the ends 48a and 48b of the joint surfaces 35a and 35b of the high-frequency transmission window 30 are connected. As a starting point, cracks may occur toward the inside of the high-frequency transmission window 30.

In the high-frequency transmission window structure 17 of the present embodiment, the width W1 of the joint portions 39a and 39b of the inner conductor sleeve 31a and the outer conductor sleeve 31b is smaller than the width W2 of the joint surfaces 35a and 35b of the high-frequency transmission window 30, and the joint portion 39a. The joint surfaces 35a and 35b of the high-frequency transmission window 30 are brazed to the central portions 44a and 44b in the width direction, and the depth dimension D1 of the grooves 40a and 40b faces the grooves 40a and 40b. , 35b is provided smaller than the width dimension W3 of the outer portions 45a and 45b in the width direction. As a result, the meniscus portions 47a, 47b of the brazing filler metal 37a, 37b formed between the lateral outer portions 45a, 45b of the joint surfaces 35a, 35b of the high-frequency transmission window 30 and the side surfaces 42a, 42b of the joint portions 39a, 39b. The thickness of the outer portions 45a and 45b in the width direction of the joint surfaces 35a and 35b is thin on the ends 48a and 48b, and the joints are formed from the ends 48a and 48b of the outer portions 45a and 45b in the width direction of the joint surfaces 35a and 35b. The thickness gradually increases toward the side surfaces 42a and 42b of 39a and 39b, and is joined to the entire surface of the side surfaces 42a and 42b of the joints 39a and 39b to reach the bottom surfaces 43a and 43b of the grooves 40a and 40b. Therefore, the joint area of the high-frequency transmission window 30 is the same as before, and the joint strength can be increased by dispersing and relaxing the stress applied to the ends 48a and 48b of the joint surfaces 35a and 35b of the high-frequency transmission window 30. it can. As a result, it is possible to prevent cracks from occurring in the high frequency transmission window 30.

The brazing joint structure between the high-frequency transmission window 30 of the high-frequency transmission window structure 17 and the sleeve (inner conductor sleeve 31a and outer conductor sleeve 31b) is not limited to the high-frequency input coupler 10 described above, and for example, a micro such as a klystron or the like. In a wave electron tube, it can also be applied to a high frequency transmission window structure provided in an output waveguide that outputs an amplified high frequency.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

10 High frequency input coupler
17 High frequency transmissive window structure
30 High frequency transmission window
31a Inner conductor sleeve as a sleeve
31b Outer conductor sleeve as a sleeve
35a, 35b joint surface
37a, 37b wax material
39a, 39b joint
40a, 40b groove
42a, 42b side
44a, 44b Central part in the width direction
45a, 45b outer part in the width direction
47a, 47b Meniscus
48a, 48b end

Claims (4)

A high-frequency transmission window with a joint surface and
The joint surface of the high-frequency transmission window is provided with a sleeve to be brazed to be joined.
The sleeve is provided at a width smaller than the width of the joint surface of the high-frequency transmission window, and is provided along both sides of the joint portion and the joint portion where the central portion in the width direction of the joint surface is brazed to be joined. The outer portion in the width direction of the joint surface protruding from both sides of the joint portion has a groove portion facing the groove portion, and the depth dimension of the groove portion is provided smaller than the width dimension of the outer portion in the width direction of the joint surface facing the groove portion. A high-frequency transmissive window structure characterized by being brazed. A brazing material provided on the joint surface and brazed to the joint portion is provided.
The thickness of the brazing material gradually increases from the end of the outer side of the joint surface in the width direction to the side surface of the joint between the outer side of the joint surface in the width direction and the side surface of the joint. The high-frequency transmission window structure according to claim 1, further comprising a meniscus portion to be joined over the entire side surface of the joint portion. A high-frequency transmission window that is annular and has joint surfaces on the outer and inner circumferences,
An inner conductor sleeve to which the joint surface on the inner circumference of the high-frequency transmission window is brazed and joined,
It is provided with an outer conductor sleeve to which the joint surface on the outer periphery of the high-frequency transmission window is brazed and joined.
The inner conductor sleeve and the outer conductor sleeve are provided at a width smaller than the width of the joint surface of the high-frequency transmission window, and the central portion in the width direction of the joint surface is brazed to be joined, and the joint portion of the joint portion. The widthwise outer portion of the joint surface that is provided along both sides and projects from both sides of the joint portion has a groove portion that faces the widthwise outer portion of the joint surface, and the depth dimension of the groove portion faces the groove portion in the width direction outer portion. A high-frequency input coupler characterized in that it is provided smaller than the width dimension of. A brazing material provided on the joint surface and brazed to the joint portion is provided.
The brazing material gradually increases in thickness from the end of the outer side of the joint surface in the width direction to the side surface of the joint between the outer side of the joint surface in the width direction and the side surface of the joint. The high-frequency input coupler according to claim 3, further comprising a meniscus portion to be joined over the entire side surface of the joint portion.

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