JPH0760757B2 - Inorganic compound / metal thin film two-layer structure X-ray anticathode - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray anticathode, and more particularly, to a two-layer structure X-ray anticathode capable of producing more power than a conventional metallic one.

[0002]

2. Description of the Related Art X-rays are used for a wide range of purposes such as internal inspection by radiography utilizing transmissivity, elemental analysis using fluorescent X-rays, and crystal structure analysis using diffracted X-rays. However, an X-ray source with high brightness is required for more efficient and short-time measurement.

The conventional X-ray anticathode is made of copper having a high thermal conductivity, tungsten having a high melting point, or a metal material having another metal deposited thereon, and is cooled by cooling water itself. , X-rays were being generated while escaping heat.

Further, since X-rays can be generated within a range where the anticathode material is not melted by electron beam irradiation, the limit of X-ray intensity is determined by the anticathode material and the cooling capacity. There is a rotating anticathode to generate stronger X-rays. This is to cool while rotating the cylindrical anticathode,
Since the portion irradiated with the electron beam is rotating, the cooling time can be lengthened, so that strong X-rays can be generated, but the device becomes large and vibration easily occurs.

[0005]

However, in the conventional anti-cathode material, the intensity of the electron beam may be increased in order to increase the intensity of the X-ray. There is a problem that the heating of the anticathode by the electrons that did not contribute to the generation of the line becomes large and the anticathode is melted if the cooling is insufficient.

If the fixed type anticathode can more effectively dissipate heat or generate X-rays and separate heat from the current state, stronger electron beam irradiation is possible, and therefore stronger X-rays can be generated. .

The present invention has been made to solve the above-mentioned problems of the prior art and to meet such a demand, and an object thereof is to provide an X-ray anticathode capable of obtaining a larger output. .

[0008]

The inventor of the present invention has conducted extensive research on measures for sufficiently dissipating heat in the anticathode and for solving the problems of X-ray generation and heat generation, and as a result, the X-ray generating portion is used. The X-ray is effectively generated by forming a thin metal film of an anti-cathode material, while heat is mainly generated in the inorganic compound behind it, such as diamond or BN, having a high melting point and a very good thermal conductivity. In addition, the present invention has been completed based on the finding that it is sufficient to radiate heat.

That is, the X-ray anticathode according to the present invention is characterized in that a metal thin film is provided on an inorganic compound having a high melting point and a high thermal conductivity to form an inorganic compound / metal thin film two-layer structure.

The present invention will be described in more detail below.

[0011]

[Action]

The X-ray anticathode according to the present invention is an inorganic compound / metal thin film in which a metal thin film for generating a characteristic X-ray of a required wavelength is provided on an inorganic compound such as diamond or BN having a high melting point and a high thermal conductivity. It has a two-layer structure.

As the inorganic compound having a high melting point and a high thermal conductivity, diamond or BN having a light transmitting property is preferable, but other inorganic compounds can be used as long as they have a high melting point and a high thermal conductivity. These inorganic compounds are formed into a suitable thickness and shape by a method such as CVD.

The metal thin film may be any metal that can generate a characteristic X-ray having a required wavelength, such as copper, iron, or the like.
Examples include molybdenum and tungsten.

The operation of this inorganic compound / metal thin film two-layer structure X-ray anticathode is as follows. That is, the metal thin film of the anticathode material receives the energy of the electron beam to generate the X-ray. At that time, the electron beam which is not absorbed by the metal thin film is absorbed by the diamond or BN portion provided after the metal thin film and converted into heat. By cooling the rear of the diamond or BN with cooling water, the generated heat is radiated through the diamond or BN having a high thermal conductivity. By such an action, compared to the conventional anticathode which is entirely made of a metal material, less heat is generated in the part that generates X-rays and heat is radiated better. Lines can be generated.

Next, examples of the present invention will be described.

[0017]

EXAMPLE 1 FIG. 1 shows an X-ray anticathode having an inorganic compound / metal thin film two-layer structure using diamond or BN prepared by CVD as an inorganic compound and copper as a metal thin film. High thermal conductivity diamond or BN (2)
Is fixed by a holder (3) to block the front vacuum and the rear cooling water (4). Diamond or BN (2)
An anticathode material (1) of a metal thin film is attached in front of the.

In this structure, an electron beam is applied to the anticathode material of the metal thin film from the front to generate X-rays. At this time, the heat (<1 ev) generated with energy much smaller than the energy of X-ray (keV) is diamond or BN (2).
It is mainly generated in and is efficiently conducted and removed by cooling water (4). Therefore, a stronger X-ray can be generated by irradiating a stronger electron beam as compared with the conventional anticathode.

[0019]

EXAMPLE 2 FIG. 2 shows an example in which the diamond / metal thin film double layer structure X-ray anticathode of Example 1 is applied to a rotating anticathode. CVD diamond on the surface of the rotor (3 ')
This is a structure in which (2) is attached and the metal thin film (1) is attached thereon.

When this anticathode is irradiated with an electron beam (5), X-rays are emitted.
(6) occurs. At this time, the heat generated by the energy much smaller than the energy of the X-ray is the CVD diamond.
It is generated in (2), is efficiently conducted, and is removed by cooling water (4). Therefore, as compared with the conventional rotating anticathode, a stronger X-ray can be generated by irradiating a stronger electron beam. Further, if the X-ray intensity is the same, it is possible to use a smaller rotating anticathode or reduce the number of rotations.

[0021]

As described above, according to the present invention,
Of the energy of the electron beam, it does not contribute to the generation of X-rays, and the energy converted into heat can be efficiently radiated by the material with high thermal conductivity. Does not melt. Therefore, stronger X-rays can be generated. Furthermore, since diamond or BN is transparent, the shape of the focal point of the electron beam can be observed from behind by fluorescence, which has a great practical effect. Therefore, it can be used in various fields using X-rays. Is possible.

[Brief description of drawings]

Figure 1: Diamond or BN / metal thin film double layer structure X
It is explanatory drawing which shows a line anticathode.

FIG. 2 is an explanatory diagram when a diamond / metal thin film double-layer structure X-ray anticathode is applied to a rotating anticathode.

[Description of symbols] 1 metal thin film 2 diamond or BN 3 holder 3'rotor 4 cooling water 5 electron beam 6 X-ray

Claims (3)

[Claims] 1. A two-layer structure of an inorganic compound / metal thin film, in which a metal thin film which is irradiated with an electron beam to generate X-rays is provided on an inorganic compound having a high melting point and a high thermal conductivity . An X-ray anticathode that specializes in that. 2. The X-ray anticathode according to claim 1, wherein the inorganic compound having a high melting point and a high thermal conductivity is diamond or BN. 3. The X-ray anticathode according to claim 1, wherein a cooling means is provided behind the inorganic compound having a high melting point and a high thermal conductivity.