JPH06196114A - Vacuum vessel using beryllium foil - Google Patents

Abstract

PURPOSE:To provide a vacuum vessel using a beryllium foil where air-tightness of high reliability can be realized and X-rays can be efficiently radiated even when a thin beryllium foil is used. CONSTITUTION:A beryllium foil 2 is air-tightly joined to the opening 1a of a vacuum vessel. A thickness of the beryllium foil 2 is set to 100mum or less. The beryllium foil 2 is air-tightly joined to a beryllium disk 5, which is air- tightly joined to the opening 1a made of iron or an iron alloy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vacuum using beryllium foil suitable for use in, for example, an X-ray tube, an X-ray fluorescence intensifier tube, an X-ray proportional counter tube, an X-ray lithography, an X-ray detection tube and the like. Regarding the container.

[0002]

2. Description of the Related Art Generally, in an X-ray tube, an X-ray fluorescence intensifier tube, an X-ray proportional counter tube, an X-ray lithography, an X-ray detection tube, etc., beryllium is provided in an opening 11a of a vacuum container 11 as shown in FIG. The foil 12 is hermetically brazed by the brazing material 13 and used as an input window or an output window. In this case, the vacuum airtightness is maintained by a diffusion bonding method other than the brazing method or a diffusion bonding method not using the brazing material 13. And the X generated in the pipe
The wire 14 passes through the beryllium foil 12 and is emitted to the outside of the tube. X
This beryllium foil 12 is used to efficiently discharge the wire 14 to the outside. Further, the X-ray transparency is improved by making the thickness of the beryllium foil 12 as thin as possible. recently,
X-ray using beryllium foil with a thickness of 100 μm or less
There is an increasing demand to improve the radiation efficiency of 14.

[0003]

Opening 11 of vacuum container 11
The a and the beryllium foil 12 are joined by a brazing method, diffusion joining, or the like, but undergo a thermal history in the process. However, if there is a difference in the coefficient of linear expansion between the opening 11a of the vacuum container 11 and the beryllium foil 12, deformation of these members is suppressed during cooling after joining, and stress is applied to each member.
However, since the beryllium foil 12 is generally thinner than the opening 11a of the vacuum container 11, the beryllium foil 12 is heavily stressed. Recently, since the beryllium foil 12 has been thinned, the above tendency is strengthened, and the strength is also weakened, and the beryllium foil 12 is wrinkled during the cooling process without being able to withstand this stress. The vacuum tightness may be broken by cracks or cracks. Furthermore, even if it withstands during cooling, since the stress remains after cooling, the vacuum hermeticity may be broken by the thermal influence and vibration during the operation of the tube using the vacuum container 11.

The present invention solves the above-mentioned inconveniences. Even when a thin beryllium foil is used, highly reliable airtightness can be obtained and X-rays can be efficiently radiated. It is an object to provide a vacuum container using a foil.

[0005]

According to the present invention, a beryllium foil is hermetically joined to an opening, the beryllium foil is set to a thickness of 100 μm or less, and the beryllium foil is hermetically joined to a beryllium disc. This beryllium disc is a vacuum container using a beryllium foil in which an opening made of iron or an iron alloy is airtightly joined.

[0006]

According to the present invention, the stress applied to the beryllium foil due to the difference in the coefficient of linear expansion is relaxed when the beryllium foil is subjected to the heat history in the joining process in which the beryllium foil is airtightly joined to the opening. Is less likely to be damaged and high vacuum tightness can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

A vacuum container having a beryllium foil according to the present invention is constructed as shown in FIG. A beryllium disk 5 having an opening 5a is hermetically bonded via a brazing material 3. Further, the beryllium foil 2 having a thickness of 100 μm or less is formed so as to cover the central opening 5a of the disk 5.
Are hermetically joined via the brazing material 3. Each of the above-mentioned joinings is performed by a brazing method, a diffusion joining method, or the like, and vacuum tightness is maintained. In this case, the brazing material 3 may not be used as long as the vacuum tightness is maintained without the brazing material 3. Further, the order of each joining may be the same or one of them may be performed before the other. Reference numeral 4 in the figure is an X-ray.

The stress applied to each member is as follows due to the thermal history received in the final joining process for forming the above structure. Due to the difference in the linear expansion coefficient between the vacuum container 1 and the beryllium foil 2, the stress applied to the beryllium foil 2 is
When this is directly bonded, it becomes large due to the relative thinness of the beryllium foil 2, but the beryllium foil 2
The stress is relieved and reduced by passing the disk 5 of the same material and thicker than that. On the contrary, the stress applied to the vacuum container 1 is larger than that without the disk 5, and the disk 5 is also stressed, but these members are set to a thickness sufficient to withstand this stress. By doing so, no problem occurs.

In this way, the stress applied to the beryllium foil 2 due to the thermal history of the joining process is relaxed, and the vacuum hermetic performance is improved. Further, the beryllium foil 2 can be made thinner, and for example, X-rays having high-efficiency X-ray radiation characteristics can be obtained.
A line tube is realized. (Modification)

FIG. 2 shows a modification of the present invention.
The same effect as in the above embodiment can be obtained. That is, in the modified example of the present invention, an X-ray shielding cover having a higher X-ray absorption rate than the beryllium foil 2 and the disk 5 so as to cover at least a part of the beryllium disk 5 in the embodiment of FIG.
6 is attached to the vacuum container 1. The X-ray shielding cover 6 may be inside or outside the container as long as it is arranged on the X-ray propagation trajectory and covers at least a part of the disk 5. Further, the attachment location is not limited to the vacuum container 1.

Since the disk 5 is made of the same material as the beryllium foil 2 as in the above embodiment, the X-ray transmittance is high. Then, the thickness of the disk 5 should be made large enough to absorb most of the X-rays, but if the structure does not allow it, X-rays are radiated from the disk 5 to the outside and the human body and other devices are exposed. May have an adverse effect. This modification solves this problem. When used in an X-ray tube, the X-ray shielding cover 6 covers the area outside the effective diameter required for the output window. X-rays are absorbed by the cover 6, and the X-rays are not radiated from the disk 5 portion to the outside. When the beryllium foil 2 having a very high X-ray transmittance is used as in the present invention, the X-ray shielding cover 6 is provided as in this modification rather than increasing the thickness of the disk 5 more than necessary. Is effective.

[0013]

According to the present invention, the beryllium foil is set to have a thickness of 100 μm or less, and the beryllium foil is airtightly bonded to the beryllium disk, and the beryllium disk is formed in the opening made of iron or iron alloy. Since they are airtightly joined, the stress applied to the beryllium foil due to the difference in the coefficient of linear expansion is relaxed when a thermal history is applied during this joining process, the beryllium foil is less likely to be damaged, and high vacuum airtightness is achieved. can get.

[Brief description of drawings]

FIG. 1 is a sectional view showing a vacuum container using a beryllium foil according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a modified example of the present invention.

FIG. 3 is a plan view showing a vacuum container using a conventional beryllium foil.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum container, 1a ... One end opening of a vacuum container, 2 ... Beryllium foil, 3 ... Brazing material, 4 ... X-ray, 5 ... Disk, 6 ...
X-ray shielding cover.

Claims (1)

[Claims] 1. A vacuum container using a beryllium foil in which an opening is airtightly joined to a beryllium foil, wherein the beryllium foil has a thickness of 100 μm or less,
A vacuum container using a beryllium foil, wherein the beryllium foil is airtightly joined to a beryllium disc, and the beryllium disc is airtightly joined to the opening made of iron or an iron alloy.