JPH03187141A - X-ray generator - Google Patents

Abstract

PURPOSE:To prevent the generation of a gas from a sealing member, and the instrusion thereof into a vacuum chamber by directly bonding a tube body for forming the vacuum chamber to the surface integrated into the electron irradiation surface of a target, and by providing the sealing member (O-ring) on the back side of the electron irradiation surface. CONSTITUTION:A tube body 5 that forms a vacuum chamber 6 is bonded to a surface 16 integrated into an electron irradiation surface 15 of a target 1, not of a base member 3, while a sealing member 2 is provided on the side reverse to the electron irradiation surface 15 of the target 1. The sealing member 2 such as an O-ring does not face the vacuum chamber 6 thereby. The leakage of a gas generated from the O-ring for preventing the leakage of cooling water, that is, from the ringged sealing member 2, into the vacuum chamber 6, can thus be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray generation device that generates X-rays by applying electrons to a target. In particular, the target
The present invention relates to an X-ray generator in which a target is cooled by flowing a cooling liquid, such as water, on a surface opposite to a radiation irradiation surface.

[Prior Art] As the above-mentioned type of X-ray generating device, the devices shown in FIGS. 3 and 4 are known. In this X-ray generator, a cylindrical target 51 is fitted into a base member 53 via an elastic annular sealing member, a so-called O-ring 52 . As shown in FIG. 4, the lower end of the tube 55 to which the filament 54 is fixed is joined to the upper surface of the base member 53, thereby forming a vacuum chamber 56. In the vacuum chamber 56, electrons emitted from the filament 54 hit the target 51, and from there
A line is emitted. The emitted X-rays are transmitted through an
The wire is taken out to the outside through the wire takeout window 57 at an appropriate takeout angle.

The following water passages are provided inside the base member 53. That is, a water inlet 58 provided at the right end of the base member 53, a communication passage 59, and a cross-shaped spout 60 (see FIG. 3) provided at the center of the base member 53.
Communication path 61. And it is a water passage consisting of a drain port 62. Water, which is a cooling liquid, flows through this water passage in the direction of an arrow and cools the target 51.

Generally, only a few percent of the electrons irradiated onto a target are converted into X-rays, and most of them are converted into heat. Therefore, the target becomes very hot. As mentioned above, the target 51 is cooled by the water flowing through the water passage, because the target 51 is at risk of becoming abnormally hot due to electron collisions.
This is to cool down 1.

In this type of X-ray generator that uses cooling water to cool the target, there is a risk that the cooling water may leak to the outside of the water passage, particularly into the vacuum chamber 56. In order to prevent this, in the conventional device, the target 51 and the base member 53
An O-ring 52 was placed between the two to prevent leakage of cooling water.

[Invention tries to solve! +! ! [0] However, in the conventional device described above, gas is generated from the O ring 52 as the O ring 52 is heated by the target 51, and the generated gas enters the vacuum chamber 56 and lowers the degree of vacuum in the vacuum chamber. There was a situation where it decreased. As a result, abnormal discharge occurs within the vacuum chamber 56,
Problems such as oxidation of the electron irradiated surface of the target 51 have occurred.

The present invention has been made in view of the above-mentioned problems in conventional devices, and prevents gas generated from an O-ring, that is, an annular sealing member, from leaking into a vacuum chamber to prevent leakage of cooling water. The purpose is to

[Means for Solving the Problems] In order to achieve the above-mentioned object distantly, an X-ray generator according to the present invention is provided in which the tube forming the vacuum chamber is not the base member but the electron irradiation surface of the target itself. joined to a single surface,
A further feature is that the sealing member is provided on the surface of the target opposite to the electron irradiation surface.

[Function] The tube body (5) serves as the electron irradiation surface (15) of the target (1).
is joined to the side of the Therefore, the surface of the target opposite to the electron irradiation surface is a vacuum chamber (6) formed by the tube body.
) is not facing. Sealing members such as O-rings (2) are
It is provided on the surface opposite to the electron irradiation surface that does not face the vacuum chamber.

Therefore, gas generated from the sealing member due to the high temperature does not enter the vacuum chamber.

[Example] FIG. 1 shows an exploded view of the main parts of an X-ray generator according to the present invention.

In the figure, target l consists of an electron irradiation surface 15 and a flange 16. This target 1 is fixed to a base member 3 via an O-ring 2 by fastening means (not shown) such as bolts. In this case, as shown in Figure W2, the entire lower surface of the target flange 16 comes into contact with the base member 3. In a state where the target 1 and the base member 3 are combined, the water receiving port 8, the communication path 9, and the cross-shaped spout 10 are connected.
, communication path 11. The drainage port 12 forms a water passage, similar to the conventional device shown in FIG.

In the assembly of the target 1 and the base member 3, as shown in FIG.
combined by Two water passages, a water supply channel 17a and a drainage channel 17b, are formed in advance in the pipe body 5 along the axial direction, and the water supply channel 17a communicates with the water intake port 8 of the target, and the drainage channel 17b communicates with the water intake port 8 of the target. It communicates with the drain port 12. The filament 4 and an air suction means (not shown) are attached to the tube body 5.

As the air is drawn by the air suction means,
The vacuum chamber 6, which is a space surrounded by the tubular body 5, is evacuated. In this vacuum state, electrons are emitted from the filament 4, collide with the electron irradiation surface 15 of the target 1, and generate X-rays therefrom. These X-rays are extracted to the outside through a window similar to the X-ray extraction window 57 shown in FIG. 4 (hidden in the water supply pipe 17a in FIG. 2).

A water supply means (not shown) is connected to the water supply pipe 17a in advance. While the X-rays are being generated as described above, the cooling water sent out from the water supply means flows through the passageway formed between the target 1 and the base member 3, thereby cooling the target 1. be done.

In this embodiment, the tube body 5 is the electron irradiation surface 15 of the target 1.
The O-ring 2 is directly joined to the upper surface of the flange 16, which is the same surface as the electron irradiation surface 1 of the target l.
5, that is, the lower surface of the flange 16. Therefore.

Even if the target temperature becomes high and gas is generated from the O-ring 2, the gas will not flow into the vacuum chamber 6. Thereby, a decrease in the degree of vacuum in the vacuum chamber 6 or oxidation of the electron irradiated surface 5 of the target can be prevented.

Further, the O-ring 2 is provided at the flange 16 portion of the target 1, and since this flange portion is in full contact with the base member 3, it is cooled to a relatively low temperature. The ring itself does not become too hot, and therefore the generation of gas from the O-ring 2 is also reduced.

Although the present invention has been described above with reference to one embodiment, the present invention is not limited to that embodiment.

For example, the materials and shapes of the target 1, base member 3, tube body 5, etc. can be variously changed within the scope of the present invention.

Further, the purpose of the O-ring 2 is to prevent cooling water from leaking to the outside, and as long as this purpose is distantly related, any other material and shape may be used. can.

[Effects of the Invention] According to the present invention, the tube for forming the vacuum chamber is directly joined to the same surface as the electron irradiation surface of the target, and
A sealing member (O-ring) is provided on the back side of the electron irradiation surface. Therefore, the sealing member itself does not become very hot, so gas generation from the sealing member can be suppressed to a low level. Further, even if gas is generated, it can be completely prevented from entering the vacuum chamber within the tube.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of essential parts of an embodiment of an X-ray generator according to the present invention, FIG. 2 is a side sectional view of the embodiment, and FIGS. 3 and 4 are conventional X-ray generators. It is a figure showing an example. l...Target 2...O-ring 5...
・Pipe body 6... Vacuum chamber 8... Water inlet 9, 11... Communication path 10... Spout port 12... Drain port 15... Electron irradiation surface 17a, 17b - Water passage

Claims (1)

[Claims] In a vacuum chamber formed by a tube, electrons are applied to the electron irradiation surface of the target to generate X-rays,
At the same time, this is an X-ray generator that cools the target by flowing a cooling liquid to the surface opposite to the electron irradiation surface of the target, and the tube body is joined to the electron irradiation surface side of the target, An X-ray generator characterized in that a sealing member is provided on a surface opposite to the surface to prevent a cooling liquid from leaking to the outside.