JPH083559B2 - Soft X-ray extraction window - Google Patents

Description

TECHNICAL FIELD The present invention relates to a soft X-ray extraction window provided in an ultra-high vacuum container, and particularly to the structure thereof.

[Prior Art] Conventionally, a metal beryllium foil has been widely used as an X-ray transparent material in consideration of X-ray transparency, mechanical strength, good heat radiation, airtightness of the transparent material itself, and the like. ing. Further, in the soft X-ray region, it is necessary to make the X-ray passage ultra-high vacuum in order to eliminate the attenuation of X-rays due to the atmosphere. However, not only the X-ray transparent material itself but also this and the ultra-high vacuum container The joint must also be airtight. As a method for joining a metal beryllium foil and an ultra-high vacuum container that satisfy both airtightness and mechanical fixation, brazing, electron beam welding, bonding with epoxy resin, etc. are used.

[Problems to be Solved by the Invention] However, among the conventional joining methods of a metal beryllium foil and an ultra-high vacuum container wall, all or part of a transparent material such as brazing or electron beam welding is used. The method of increasing the temperature causes an increase in the crystal grain size of metal beryllium and grain boundary deviation, which deteriorates the mechanical strength of metal beryllium and loses the airtightness of the foil before bonding. There is.

Further, in the case of bonding with an epoxy resin, since there is no temperature rise during bonding, the mechanical strength and airtightness described above do not deteriorate, but during use as an X-ray extraction window, the epoxy resin, which is an organic substance, is However, there is a drawback in that radiation deterioration occurs due to, and long-term reliability cannot be expected.

An object of the present invention is to solve the above-mentioned problems, without causing deterioration of mechanical strength and airtightness of a soft X-ray transparent material and radiation deterioration of a window, and it is possible to maintain airtightness with high reliability and long life, It is an object of the present invention to provide a soft X-ray extraction window having a structure that allows easy repair and regeneration of the window.

[Means for Solving the Problems] The present invention provides a soft X-ray extraction window that is formed of an X-ray transparent material in an opening of an ultrahigh vacuum container, and the soft X-ray extraction window includes a window frame that borders the opening. The innermost surface 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 has a predetermined softness and vapor pressure. A soft X-ray, characterized in that an annular member formed of a metal having a characteristic and having a smooth surface and a rectangular cross section is fitted, and an X-ray transmitting material is fastened between the annular member and the holding plate. It is a wire extraction window.

[Operation] An airtight method in which a cylindrical oxygen-free copper plate having a rectangular cross section is sandwiched from both sides by a knife edge having a sawtooth cross section has been put into practical use as a fastening means for an ultra-high vacuum flange.

FIG. 2 is a cross-sectional view for explaining the above-mentioned principle of hermetic sealing, and shows only the cross section of the lower half of the rotational symmetry axis. When joining two pipes 21a and 21b with their axes common, a flange 23 having a circular knife edge 22 having a sawtooth cross section is welded to the pipes 21a and 21b, and the cross section is rectangular and annular. With the oxygen-free copper gasket 24 between the knife edges 22, the two flanges 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 the force A in the drawing is applied to tighten the flange, the hard knife edge 22 crushes the soft gasket 24, and the force B acts in the gasket 24 due to the inclination of the knife edge.
The force C is the crushed outer circumference of the gasket 24 and the flange 23.
The reaction received from the wall after hitting it causes the gasket 24 to be pressed against the knife edge 22 and a hermetic seal is achieved.

On the other hand, in the soft X-ray extraction window of the present invention, a narrow annular ridge having a flat and smooth surface is provided on the innermost side of the window frame flange, and the outer side thereof has a slope inclined toward the ridge. It has a circular knife edge. An annular member made of a metal having a predetermined softness and vapor pressure characteristic is fitted to the outer circumference of the ridge, and an X-ray transparent material serving as a window material is placed on the annular member to hold it down. Hold down with. For example, upon tightening with a hex socket bolt, the annular member is crushed by the knife edge, creating a force in the direction of the slope of the edge that pushes the ridge into the metal annulus. Airtightness is maintained by this pressing force and the reaction force from the ridge to the surface of the edge slope. On the other hand, the contact portion between the annular member and the X-ray transparent material must also be airtight,
This is accomplished by rubbing between the flat and smooth annular member surface and 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 one embodiment of the present invention. In the figure, 1 is stainless steel SUS30 with an outer diameter of 152 mm.
4-sided Conflat window frame flange with a diameter of 35m in the center
It has a circular through hole with a width of 2 mm and a height of 3 at the inner edge that touches the through hole.
It has an annular ridge 2 of mm. The upper surface of the ridge 2 is finished flat and smooth, and the outer circumference of the ridge 2 is perfectly round and smooth. Further, on the outer side of the ridge 2 of the flange 1, a knife edge 3 is formed with a slope toward the ridge 2 side.
Is provided. On the outside of the ridge 2, an oxygen-free copper annular ring 4 having a rectangular cross-section with an inner diameter equal to the outer diameter of the ridge and a thickness of 3 mm and a width of 6 mm is shrink-fitted. The upper and lower surfaces of the annular ring 4 are also flat and smooth, the inner surface is perfectly circular and smooth, and the upper surface has a gold thin film 5 with a thickness of about 1.5 μm.
Are stacked. A metal barium foil 6 with a thickness of 30 μm and a diameter of 50 mm that has been tested for airtightness is placed on this surface, and pressed with a 12 mm-thick stainless steel holding plate 7, and eight M8 hexagon socket head cap bolts 8 and spring washers 9, Tighten with plain washers 10. Tightening is performed until the upper surface of the ridge 2 and the lower surface of the pressing plate 7 sandwich and fix the metal varirim foil 6. The gold thin film 5 on the upper surface of the copper ring 4 is for filling irregularities on the surface of the beryllium foil 6 to complete airtightness.

The beryllium window flange 1 that has been assembled is attached to a general ultra-high vacuum device by bolting the through tap hole 13 with a normal con-flat edge 12 and an oxygen-free copper gasket (not shown). To be

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

According to the structure of the present invention, a highly airtight joint can be easily expressed, and since no heat is applied to the X-ray transmissive material when manufacturing the window, the strength of the window material is not deteriorated.
A wire take-out window is obtained. Moreover, since no organic substance is used at all, it is free from both vacuum deterioration due to scattering of the organic substance and short life due to radiation deterioration. Furthermore, unlike brazing, welding, and epoxy bonding,
Even when the X-ray transparent material is aged or fatigued, it can be easily replaced and the window can be reused.

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

[Effects of the Invention] As described above, according to the present invention, highly reliable and long-life airtightness can be maintained without deteriorating the mechanical strength and airtightness of the X-ray transparent material and the radiation deterioration of the window itself. It is possible to provide a soft X-ray extraction window which is possible and has a structure in which repair and regeneration of the window are easy.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a soft X-ray extraction window according to the present invention, and FIG. 2 is a sectional view of a vacuum seal for explaining the function of hermetic sealing. 1 ... Window frame flange, 2 ... Circular ridge 3,22 ... Knife edge, 4 ... Circular ring 5 ... Gold thin film, 6 ... Metal beryllium foil 7 ... Stainless steel holding plate 8 ... Hexagonal hole Attached bolt, 9 …… Spring washer 10 …… Plain washer, 11 …… Tap hole 12… Conflat edge 13… Through tap hole, 21 …… Pipe 23 …… Flange, 24 …… Gasket

Claims (1)

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