JPH02272399A - Soft x-ray taking-out window - Google Patents

Abstract

PURPOSE:To prevent the degradation of airtightness and radiation by forming a knife edge on the outside peripheral part of the innermost annular projection of a window frame and binding an X-ray transmission material between a specific annular member fitted to the outside peripheral part of the projection and a retaining member. CONSTITUTION:A circular through hole is formed in the center part of a double- faced conflat window frame flange 1, and a flat and smooth annular projection 2 is formed on its inside edge, and a knife edge 3 where a slope is formed toward the projection 2 is formed on the outside of the projection 2. A metallic ring 4 which has prescribed consistency and vapor pressure characteristic and is made of oxygen free copper or the like is fitted to the outside peripheral part of the projection 2, and a metallic beryllium foil 6 is placed on the ring 4 and is pressed by a retaining plate 7 made of stainless steel, and a bolt 8, a spring washer 9, and a flat washer 10 are used to clamp it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soft X-ray extraction window provided in an ultra-high vacuum container, and particularly to its structure.

[Conventional technology] Conventionally, X-ray transparency has been used as an X-ray transparent material.

Metallic beryllium foil is widely used because of its mechanical strength, good heat dissipation, and airtightness of the transparent material itself. In addition, in the soft X-ray region, it is necessary to create an ultra-high vacuum in the X-ray path to eliminate X-ray attenuation due to the atmosphere.
Not only the radiolucent material itself but also the joint between it and the ultra-high vacuum container must be airtight. Brazing and electron beam welding are methods for joining metal beryllium foil and ultra-high vacuum containers that satisfy both airtightness and mechanical fixation.

Adhesion using epoxy resin is used.

[Problems to be Solved by the Invention] However, among the conventional methods of joining metal beryllium foil and the wall of an ultra-high vacuum container, such as brazing and electron beam welding, it is difficult to connect all or part of the transparent material. The method of raising the temperature causes an increase in the crystal grain size of the metal beryllium and grain boundary segregation, which has the disadvantage that the mechanical strength of the metal beryllium deteriorates and the airtightness of the foil that it had before joining is lost. be.

In addition, when bonding with epoxy resin, there is no temperature rise during bonding, so the aforementioned deterioration of mechanical strength and airtightness does not occur. However, when used as an X-ray extraction window, the epoxy resin covered with organic matter The drawback is that long-term reliability cannot be expected due to radiation deterioration caused by radiation.

The purpose of the present invention is to solve the above-mentioned problems, and to enable highly reliable and long-life airtight maintenance without causing deterioration of the mechanical strength or airtightness of soft X-ray transparent materials or deterioration of windows due to radiation.
To provide a soft X-ray extraction window having a structure that allows easy repair and regeneration of the window.

Means for Solving the Problem] The present invention provides a soft X-ray extraction window that is located at the opening of an ultra-high vacuum container and is formed of an X-ray transparent material. The window frame includes an annular ridge with a flat and smooth surface formed on the innermost side of the window frame, and a serrated knife edge formed on the outer periphery of the ridge, and the outer periphery of the ridge has predetermined softness and vapor pressure characteristics. An annular member made of a metal having a smooth surface and a rectangular cross section is fitted, and an X-ray transparent material is fastened between the annular member and a holding plate. It is a take-out window.

[Operation] An airtight method in which an annular oxygen-free copper plate with a rectangular cross section is sandwiched between knife blades with a serrated cross section on both sides has been put to practical use as a fastening means for ultra-high vacuum flanges.

Figure 2 is a cross-sectional view explaining the principle of hermetic sealing described above.
Only the lower half section of the axis of rotational symmetry is shown. When joining two pipes 21a and 21b with a common axis, a flange 23 having a circumferential knife 22 with a serrated cross section is welded to the pipes 21a and 21b, and a circular knife with a rectangular cross section is welded to the pipe 21a and 21b. An oxygen-free copper gasket 24 is sandwiched between the knife fittings 22, and the two 7-lunges 23 are opposed to each other and tightened with bolts. FIG. 2 shows a state in which the gasket 24 is only sandwiched but not yet tightened.

When a force is applied in the figure to tighten the flange, the hard knife 22 crushes the soft gasket 24, and a force B acts in the gasket 24 due to the slope of the knife. Force C is the crushed gasket 2
The reaction force received from the wall of the flange 23 after the outer periphery of the flange 4 hits the wall of the flange 23 causes the gasket 24 to be pressed against the knife flange 22 to achieve a hermetic seal.

On the other hand, in the soft X-ray extraction window of the present invention, a narrow annular ridge with a flat and smooth surface is provided on the innermost side of the window frame flange, and the outside thereof has a slope that slopes toward the ridge. It has a circumferential knife. An annular member made of a metal having a predetermined softness and vapor pressure characteristics and having an inner circumferential diameter that fits without a gap on the outer circumference of the protuberance is fitted,
An X-ray transparent material that will serve as a window material is placed on top of this and pressed down with a presser plate. For example, when tightening with a hexagon socket port,
The annular member is crushed by the knife edge, and the orientation of the slope of the edge creates a force in the metal ring that pushes the ridge. Airtightness is maintained by this pressing force and the force on the sloped surface of the edge due to the reaction from the bulge. On the other hand, the contact area between the annular member and the X-ray transparent material must also be airtight, and this is achieved by rubbing the flat and smooth surface of the annular member against the X-ray transparent material.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view schematically showing the structure of an embodiment of the present invention. In the figure, 1 is a stainless steel t with an outer diameter of 152 mm.
f4 SUS 3041 double-sided flat window frame flange, which has a circular through hole with a diameter of 35 mm in the center, and an annular ridge 2 with a width of 2 mm and a height of 3 mm on the inner edge in contact with the through hole. The upper surface of the bump 2 is finished flat and smooth, and the outer periphery of the bump 2 is finished perfectly round and smooth.

Further, on the outside of the protuberance 2 of the flange, a knife ridge 3 is provided which is sloped toward the protuberance 2 side.

An annular ring 4 made of oxygen-free copper having a rectangular cross section and a thickness of 3 mm and a width of 6 mm is shrink-fitted onto the outside of the protuberance 2 and has an inner diameter equal to the outer diameter of the protuberance. The upper and lower surfaces of the ring 4 are finished flat and smooth, the inner surface is finished perfectly round and smooth, and a thin gold film 5 with a thickness of about 1.5 strands is laminated on the upper surface. Thickness 301J on this side! n, a metal beryllium foil 6 with a diameter of 50 mm that has been tested for airtightness is placed, and the thickness is 12 m.
8 M8 hexagon socket head bolts 8 and spring washers 9. Tighten using flat washers 10. Tightening is performed until the metal beryllium foil 6 is clamped and fixed between the upper surface of the protuberance 2 and the lower surface of the holding plate 7. The gold thin film 5 on the upper surface of the copper ring 4 is used to fill in the irregularities on the surface of the beryllium foil 6 to ensure complete airtightness.

The assembled beryllium window flange 1 can be attached to a general ultra-high vacuum device by bolting the through tapped hole 13 using a normal conflat edge 12 and an oxygen-free copper gasket (not shown). It will be done.

In addition to oxygen-free copper laminated with gold, silver or the like may be used as the soft metal ring.

According to the structure of the present invention, a highly airtight joint can be easily realized, and since no heat is applied to the X-ray transparent material during sensitization, there is no deterioration in the strength of the window material, resulting in highly reliable soft X-ray extraction. The window is reduced by 1q. Furthermore, since no organic material is used, there is no problem with either vacuum deterioration due to organic material scattering or short life caused by radiation deterioration. Rough and wax welding.

Unlike welding or epoxy bonding, it is easy to replace even when the X-ray transparent material deteriorates over time or becomes fatigued, allowing the window to be reused.

All of these effects effectively contribute to improving the reliability and reducing the cost of the soft X-ray extraction window.

[Effects of the Invention] As explained above, according to the present invention, highly reliable and long-life airtight maintenance can be achieved without causing deterioration of the mechanical strength or airtightness of the X-ray transparent material or radiation deterioration of the window itself. Therefore, it is possible to provide a soft X-ray extraction window with a structure that allows easy repair and reproduction of the window.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the soft X-ray extraction window according to the present invention, and FIG. 2 is a sectional view of a vacuum seal for explaining the effect of airtight sealing. 1... Window frame flange 2... Annular protuberance 3.2
2... Knife 5... Gold thin film 7... Stainless steel presser plate 8... Hexagonal hole port 10... Flat washer 12... Conflat edge 13... Through tapped hole 23...・Flange 4...Ring 6...Metal beryllium foil 9...Spring washer 11...Tapped hole 21...Pipe 24...Gasket Ultra-high vacuum - Knee atmospheric pressure

Claims (1)

[Claims] (1) In a soft X-ray extraction window formed of an X-ray transparent material at the opening of an ultra-high vacuum container, the window frame that frames the opening has a surface formed on the innermost side of the window frame. has a flat and smooth annular ridge and a serrated knife edge formed on the outer periphery of the ridge, and the outer periphery of the ridge is made of a metal having predetermined softness and vapor pressure characteristics and is smooth. A soft X-ray extraction window characterized in that an annular member having a rectangular surface and a rectangular cross section is fitted, and an X-ray transparent material is fastened between the annular member and a presser plate.