JPS5939858B2 - X-ray tube equipment - Google Patents

Description

[Detailed description of the invention] This invention relates to an X-ray tube device.

In methods such as computed tomography, which has become widely practiced in recent years, by repeating exposure many times to obtain a single X-ray photograph, changes in the amount of Xi at each repetition directly change the image. , the X-ray output outside the subject is directly detected and used as the reference X-ray dose before exposure.

In order to detect this X-ray, the effective irradiation field 1 of the X-ray tube device must be larger than the subject 2, as shown in FIG.

Therefore, it is necessary to enlarge the radiation window of the X-ray tube device, which contradicts the desire to make the X-ray tube device as compact as possible.

Furthermore, by increasing the effective irradiation field, X-rays are emitted over a wider area, which increases the possibility of unnecessary X-ray exposure.

In FIG. 1, numeral 3 represents an X-ray tube focal point, and numeral 4 represents a reference detector.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an X-ray tube device that prevents unnecessary exposure to X-rays and is miniaturized.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

This invention aims to incorporate the recent miniaturization of X-ray detectors into an X-ray tube device to perform reference X-ray dose measurements.

That is, recent technological advances have made X-ray detectors more compact, and extremely small X-ray detectors and ionization chambers are now available.

It is relatively easy to incorporate these into the tube, but if the X-ray tube is made of an envelope made of only an insulating material such as Galanus, placing these detectors near the envelope will cause damage to the inner surface of the envelope. The wall charge will cause an electrical discharge that can damage the x-ray tube or detector.

Therefore, the X-ray tube device of the present invention is constructed as shown in FIGS. 2 and 3, in which a cathode 6 and a rotating anode γ are disposed facing each other in a grounded metal vacuum envelope 5. .

The vacuum envelope 5 is provided with an effective X-ray emission window 8 and an X-ray detector mounting window 9 in the vicinity thereof at positions parallel to (corresponding to) the focal trajectory of the anode 1.

The effective X-ray emission window 8 is made of Be with a minimum diameter that covers the object.

Furthermore, the window 9 is also made of Be, and as is clear from FIG. 3, an X-ray detector 10 is attached to this window on the outside of the tube.

The X-ray detector 10 may be mounted by fixing it using an adhesive 11 after the evacuation process of the X-ray tube is completed, or by a mechanical method such as attaching a mirror or caulking.

The X-ray tube device of the present invention is constructed as described above and shown in the drawings, and includes an X-ray radiation window 8 provided in the vacuum envelope 5 and an X-ray detector 10 mounted near the X-ray radiation window 8. Therefore, this X-ray detector 10 can accurately detect the reference dose.

Moreover, there is no need to undesirably expand the irradiation field of X-rays irradiated to the subject.

Note that the X-ray detector mounting window 9 may be located anywhere in the vicinity of the effective X-ray emission window 8 as long as it can see through the focal point, that is, a position parallel to the focal trajectory of the anode.

In the above embodiment, Be is also attached to the window 9, but depending on the performance of the X-ray detector, the metal vacuum envelope 5 may be used as is and the X-ray detector 10 may be attached to the outer surface thereof. Also, by changing the material of this window 9, the energy dependence of the X-ray detector 10 can be improved.

Furthermore, the X-ray detector may not be attached to the surface of the vacuum envelope 5, but may be fixed inside the tube container to directly measure the amount of X-rays emitted from the target.

At this time, by embedding the X-ray detector 10 into the wall of the tube container, the same effect as in the above embodiment can be expected even in the vacuum envelope made of an insulator.

Moreover, FIGS. 4a and 4b show a modification of this invention,
The same effects as in the above embodiment can be obtained.

That is, the window 9 in the above embodiment is deleted, leaving only the effective X-ray emission window 8, and an annular X-ray is formed around the effective X-ray emission window 8.
A line detector 12 is provided.

In other words, the X-ray dose is measured at the effective X-ray emission window 8, and the detector sensitivity and accuracy can be increased.

As explained above, according to the present invention, an X-ray tube device with great practical value can be provided.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing a conventional X-ray tube device, Fig. 2 is a front view showing an X-ray tube device according to an embodiment of the present invention, and Fig. 3 is an enlarged view of the main parts of Fig. 2. A sectional view shown in FIG. 4a,
b is a front view and a sectional view showing a modification of the invention. 5... Vacuum envelope, 6... Cathode, γ.
...Anode, 8...Effective X-ray emission window, 9.
...X-ray detector mounting window, 10...X-ray detector.

Claims (1)

[Claims] 1. An anode is disposed within a metal vacuum envelope, an X-ray emission window is provided in the vacuum envelope, and an X-ray detector is installed near the X-ray emission window. An X-ray tube device characterized by: 2. The X-ray tube device according to claim 1, wherein the anode is of a rotating type and the X-ray detector is provided at a position parallel to the focal trajectory of the anode. 3. The X-ray tube device according to claim 1, wherein the X-ray detector is in its current state and the annular X-ray detector is attached around the X-ray emission window.