JPH06188092A - X-ray generating target, x-ray source, and x-ray image pickup device - Google Patents

Abstract

PURPOSE:To provide an X-ray image pickup device provided with a high-output X-ray source by composing the X-ray source of an X-ray generating target having a micro-focal point size which can be cooled. CONSTITUTION:A micro-electron beam 1 is radiated to a target T having an X-ray generating layer 5 comprising a support body 7, an electron absorption layer 6 jointed with it, and a tungsten film deposited on it. Heat generated by radiation of the electron beam 1 is cooled by cooling medium 16. An X-ray 4 generated from the X-ray generating layer 5 is taken, it is radiated to a sample 48, and its transmission image is detected by an X-ray image intensifier 50 and a cooling type CCD camera 54. Where a beam diameter of the electron beam 1 is set to be less than 1mum, with thickness of the tungsten film in the X-ray generating layer 5 set at 1mum, an X-ray source of a micro-focal point size of about 1mum, thereby a clear fluoroscopic image without having a half shadow blurr can be provided by an X-ray image pickup device provided with this X-ray source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray generating target, an X-ray source and an X-ray imaging apparatus, and more particularly to an X-ray generating target and a micro focus suitable for high resolution X-ray fluoroscopy. X-ray source and X
The present invention relates to a line imaging device.

[0002]

2. Description of the Related Art A high resolution is required for a conventional X-ray imaging apparatus. One factor that governs the detection resolution in an X-ray imaging device is the focal dimension of the X-ray source. For this reason, a microfocus X-ray source with a micro focus is used in an X-ray imaging apparatus that requires high resolution. An X-ray generation target (hereinafter referred to as a target) used for a microfocus X-ray source is a target.
It is roughly classified into a reflection type that uses X-rays emitted laterally from the target and a transmission type that uses X-rays transmitted through the target.

The reflective target is excellent in the cooling property of the target, but has a drawback that it is disadvantageous in the resolution because the spread of the electron beam in the target becomes large. The transmissive target is excellent in resolution because it can reduce the spread of the electron beam in the target, but has the drawback of poor cooling performance. However, generally, a transmission type target has been often used because of its advantage that the spread of the electron beam is small.

First, a conventional technique will be described with reference to FIG. FIG. 20 is a sectional view of a conventional transmission type target. In FIG. 20, 1 is a focused electron beam, 2 is a thin film target, 3 is a region, and 4 is an X-ray. The X-ray accelerates the focused electron beam 1 of the thermoelectrons emitted from the cathode by a high DC voltage and irradiates the thin film target 2 to generate X-ray 4 in the region 3. X transmitted through this thin film target 2
Line 4 is used. The size of the X-ray generation region 3 is determined by the acceleration voltage of the focused electron beam 1, the beam diameter, and the material and film thickness of the target 2.

In order to obtain an X-ray with a minute focus size,
Although the film thickness of the target 2 has to be made thin, it is disadvantageous in terms of temperature rise, and there is a fatal defect that a high-output target and X-ray source cannot be obtained. An X-ray source using such a transmissive target is described in, for example, Japanese Patent Application Laid-Open No. 3-274500, but a focused electron beam 1 is irradiated on the transmissive target 2 to obtain a fine focus. It was to get a size X-ray source.

Further, for characteristic X-rays, which have recently been expanded in application fields, various X-rays having different wavelengths are often used. For that purpose, the material of the target is changed every time the wavelength is changed. It had the drawback of having to.
Further, the inability to obtain the above-mentioned high-output target and X-ray source has also been a cause of the drawback that the X-ray imaging apparatus does not have high resolution.

[0007]

The reflective target is excellent in cooling property, and even if it is attempted to take advantage of obtaining a high-output target and an X-ray source,
Since it has a constant thickness, there is a problem that the X-ray generation region by the focused electron beam irradiated is enlarged and the focus size cannot be reduced. Further, the problem that the focus size cannot be reduced is also a problem that a microfocus X-ray source having a fine focus necessary for high-resolution fluoroscopy cannot be obtained. Furthermore, the replacement of the material of the target when changing the wavelength of the characteristic X-ray is carried out by stopping the vacuum device of the image pickup device, which requires a long time and is not practical. Furthermore, the various problems described above are also the cause of the problem that a high-resolution X-ray imaging apparatus cannot be obtained.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The first object of the present invention is that the X-rays have the advantages of good cooling and have a small X-ray generation region. It is to provide a target for generation.

A second object is to provide an X-ray source which can obtain high-power X-rays using the above target.
The third purpose is, in an X-ray source that outputs characteristic X-rays,
An object of the present invention is to provide an X-ray source that can easily and quickly change the wavelength by changing the material of the target. A fourth object is to provide a high resolution X-ray imaging apparatus using the above high output X-ray source.

[0010]

In order to achieve the above-mentioned first object, the structure of the first invention relating to the X-ray generating target is a thin X-ray which does not absorb the irradiated electron beam. It is composed of a ray generating layer and an electron beam absorbing layer that absorbs electrons transmitted through the X-ray generating layer. The X-ray generation layer is composed of a plurality of materials. The X-ray generation target is composed of an X-ray generator that generates X-rays having a minute focus and an electron beam absorption layer that absorbs electrons that have passed through the X-ray generator.

The X-ray generator is composed of at least one generator. Further, the X-ray generator is
It is composed of a plurality of materials. The electron beam absorbing layer is supported by a metal support. In the X-ray generating target, an electron beam absorbing layer is formed by bonding a beryllium foil to a copper-based metal plate, and an X-ray generating layer is formed by depositing a tungsten film on the electron beam absorbing layer and reflecting it. It is a shape.

Further, in order to achieve the above second object,
The structure of the second invention relating to the X-ray source is a reflection composed of a thin X-ray generation layer that does not absorb the irradiated electron beam and an electron beam absorption layer that absorbs the electrons transmitted through the X-ray generation layer. It is composed of a target for X-ray generation, means for cooling the target from the electron beam absorption layer side, and means for taking out X-rays from the X-ray generation layer side. The means for cooling from the electron beam absorbing layer side is composed of an electronic cooling element. The electron beam absorbing layer is supported by a metal support.

Further, the X-ray source comprises an X-ray generating layer having a thin thickness which does not absorb the irradiated electron beam and an electron beam absorbing layer which absorbs the electrons transmitted through the X-ray generating layer. The target is rotated. The X-ray source includes an X-ray generator that generates X-rays having a minute focus, and the X-ray generator.
It has an X-ray generating target composed of an electron beam absorbing layer that absorbs electrons transmitted through a ray generator, and the target is rotated.

The X-ray source includes means for deflecting an electron beam and means for detecting backscattered electrons and secondary electrons from the X-ray generating target. The electron beam is detected by the scanning image by the detecting means. Is focused on the target. The target for X-ray generation is provided with a mesh for focusing an electron beam at a site where X-rays are generated. The X-ray generation target is
A surface pattern for focusing an electron beam is provided on a portion where an X-ray is generated.

The X-ray source includes means for deflecting and rotating and scanning the electron beam, and an X-ray generating target equipped with an annular X-ray generator. The electron beam is rotationally scanned to rotate the X-ray generation point on the annular X-ray generator.

In order to achieve the third object, the characteristic X
According to a third aspect of the invention relating to an X-ray source for generating X-rays, there is provided an X-ray generator having a means for deflecting an electron beam and an X-ray generator having a plurality of materials or an X-ray generating layer having a plurality of materials. A target for line generation is provided, and the irradiation position of the electron beam on the target is changed by means for deflecting the electron beam to generate various characteristic X-rays.

In order to achieve the above-mentioned fourth object, the structure of the fourth invention relating to the X-ray imaging apparatus includes an X-ray generation layer and a thin X-ray generation layer which do not absorb the irradiated electron beam and have a thin thickness. An electron beam absorbing layer having an electron beam absorbing layer for absorbing the transmitted electrons is provided, and the target is irradiated with a fine electron beam to extract the X ray from the X ray generating layer side and the electron beam absorbing layer. X-ray source for cooling from the side, X-ray image intensifier for displaying an X-ray image transmitted through the sample, and cooled CC
And a detection system including a D camera.

[0018]

The operation of each of the above technical means is as follows. According to the structure of the first invention, the electron beam with which the X-ray generating target is irradiated is narrowed down and the thickness of the X-ray generating layer is made sufficiently thin so that the irradiated electron beam is not absorbed. Since the electron beam absorbing layer that absorbs the transmitted electrons is provided as two layers, the scattering region where the irradiated electron beam penetrates into the inside of the target (for example, the scattering region of the electron beam having an acceleration voltage of 100 kV is (5 μm or more) is limited, and the transmitted electrons are completely absorbed, so that the focal size can be miniaturized. Further, even if a minute X-ray generator is used for the X-ray generating layer, the same function can be obtained.

According to the structure of the second invention, most of the energy of the irradiated electron beam is heat in the X-ray generating target, and this heat is transferred from the electron absorbing layer side by the cooling means. It cools and takes heat to cool the target.
This increases the heat resistance of the target, increases the amount of X-rays that can be generated by irradiating a current-collecting electron beam with a large current, and can output high-intensity X-rays. Since the irradiation position of the electron beam changes every moment as the target rotates, a high-current collecting electron beam can be irradiated and the generated X-ray dose increases, so that a high-intensity X-ray is output.

Further, the scanning electron image of the X-ray generation layer can be detected by the means for deflecting the electron beam, and the focus of the electron beam can be surely focused on the X-ray generation layer. In particular, when a mesh is placed on the X-ray generation layer, the scanning electron image becomes clear and it is easy to focus. Further, by irradiating the electron beam, the irradiation position of the collecting electron beam can be shifted to extend the life of the target. Further, by deflecting and scanning the electron beam on the circular X-ray generator, it is possible to obtain a rotating X-ray generating point having a minute focus size.

According to the structure of the third aspect of the invention, the irradiated electron beam is deflected to irradiate a plurality of material positions of the X-ray generator or the X-ray generating layer of the X-ray generating target. The wavelength of the characteristic X-ray generated is changed by instantly switching the material of the target.

According to the structure of the fourth invention, a beam of an electron beam is emitted.
The target having a two-layer structure of a thin X-ray generating layer and an electron beam absorbing layer, which has a sufficiently small diameter, is irradiated, and the target is cooled by a cooling means to obtain high brightness. In addition, since X-rays having a minute focus size can be obtained, a clear fluoroscopic image of the sample without penumbra can be obtained, and a clear image can be obtained by displaying the fluoroscopic X-ray image of the sample.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described below with reference to FIGS. [Embodiment 1] FIG. 1 is a sectional view of a reflective target according to an embodiment of the present invention. This embodiment according to the first aspect of the present invention describes a reflective target.

In FIG. 1, 1 is a focused electron beam and 4 is X.
Lines 5, 5 are X-ray generation layers, 6 is an electron beam absorption layer, and 7 is a support, which constitute a target T. For the X-ray generation layer 5, a heavy metal having a high X-ray generation efficiency is suitable,
Further, in consideration of the heat generation action of the electron beam 6, it is made of tungsten or molybdenum having a high melting point. The thickness of the film depends on the desired X-ray focal spot size, but if a focal spot size of 1 μm is to be obtained, it is preferably around 1 μm. At this time, the beam diameter of the electron beam 1 needs to be focused to 1 μm or less.

The electron beam absorbing layer 6 is a layer that absorbs electrons transmitted through the X-ray generating layer 5. This is because, since the X-ray generation layer 5 is thin, irradiated electrons pass through the X-ray generation layer 5 and are not absorbed. For the electron beam absorbing layer 6, a light element having a low X-ray generation efficiency is suitable, and for example, beryllium or carbon having a small atomic number is suitable. The electron beam absorption layer 6 needs to have a thickness enough to absorb electrons, and is also related to the acceleration voltage of the electrons to be irradiated. 0.1 at acceleration voltage of 100 kV
mm is required, and when the acceleration voltage is 200 kV, 0.
3 mm or more is required.

The support 7 comprises an X-ray generating layer 5 and an electron beam absorbing layer 6.
And has a function of dissipating the heat generated in the X-ray generation layer 5 by the irradiation of the electron beam 1. Therefore, a metal having a high thermal conductivity is suitable, and for example, copper is used. Since the target is in vacuum, oxygen-free copper or phosphor bronze is suitable. This target is cooled via the support 7.

The focused electron beam 1 accelerated by the high DC voltage collides with the X-ray generation layer 5 to generate X-rays 4. The X-rays 4 generated in the X-ray generation layer 5 are extracted from the side of the X-ray generation layer 5 side, and the target is used as a reflection type.

An example of a method of manufacturing the target shown in this embodiment will be described. First, for the support 7 and the electron beam absorbing layer 6, the oxygen-free copper plate and the beryllium foil are heated in a vacuum furnace at 800-
It is formed by heating at 900 ° C. and diffusion bonding. after that,
The X-ray generation layer 5 is formed by depositing a tungsten film by sputtering or CVD, and the target T is completed.

[Embodiment 2] Another embodiment of the first invention will be described. FIG. 2 is a sectional view of a reflective target according to another embodiment of the present invention. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same parts, and thus detailed description thereof will be omitted. Only new symbols will be described. 8 is an X-ray generator.

As shown in FIG. 2, the reflective target of this embodiment according to the first invention is the same in principle as that of [Embodiment 1], and the X-ray generation layer 5 of [Embodiment 1] is used. Is a thin film, but the X-ray generator 8 of this embodiment is a minute mass. For this reason, in [Example 1], the beam diameter of the focused electron beam 1 with respect to the X-ray generation layer 5 needs to be narrow and focused.
The beam diameter of the focused electron beam 1 with respect to the X-ray generator 8 of the present embodiment can be a fine X-ray focal spot size even if the beam diameter is not necessarily narrow.

The reflective target of this embodiment comprises an X-ray generator 8, an electron beam absorbing layer 6 and a support 7.
When the X-ray generator 8 is irradiated with the focused electron beam 1, X-rays 4 are generated from the X-ray generator 8. The X-ray generator 8 is preferably a heavy metal having a high X-ray generation efficiency, such as tungsten or molybdenum having a high melting point. The size depends on the desired X-ray focal spot size, but the size is 1 μm.
Then, a focus size of 1 μm can be obtained. Electron beam absorption layer 6
Since the support 7 is the same as that in [Example 1], detailed description thereof is omitted.

[Embodiment 3] Another embodiment of the first invention will be described. FIG. 3 is a sectional view of a reflection type target according to another embodiment of the present invention. In FIG. 3, the same reference numerals as those in FIG. 2 denote the same parts, and detailed description thereof will be omitted. Only new symbols will be described. 9 is a protective layer. As shown in FIG. 3, the reflective target of the present embodiment according to the first invention is the same in principle as that of [Embodiment 2], except that a protective layer 9 is added.

The reflective target of this embodiment comprises an electron beam absorbing layer 6, a support 7, an X-ray generator 8 and a protective layer 9. The protective layer 9 mechanically protects the X-ray generator 8 and has an action of preventing the X-ray generator 8 from falling over. Light elements having a low X-ray generation efficiency are preferable because it is necessary to reduce the number of reflected electrons and secondary electrons due to the focused electron beam 1 and prevent the generation of X-rays due to these electrons.

An example of the manufacturing method of the reflective target according to the above [Embodiment 2] and [Embodiment 3] will be described. First, the support 7 and the electron beam absorption layer 6 are formed by heating an oxygen-free copper plate and a beryllium foil to 800 to 900 ° C. in a vacuum furnace and diffusion bonding them. After that, a tungsten film is deposited on this by sputtering or CVD. A resist is applied on the tungsten film, exposed by an electron beam, the resist is developed, and then the unnecessary tungsten film is etched to form a portion to become the X-ray generator 8. Then, the resist is removed to complete the reflective target of [Example 2]. Further, when a protective layer 9 is formed by applying polyimide, the reflective target of [Example 3] is completed.

[Embodiment 4] Still another embodiment of the first invention will be described. FIG. 4 is an explanatory view of a target according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 20 is a heat absorbing portion, and 21 is a rotating shaft. This example is based on [Example
1], [Embodiment 2], [Embodiment 3] is different from the target in that the target is rotated. As a result, the irradiation position of the electron beam changes every moment, and the temperature rise of the irradiated portion of the target is suppressed.

The target T of this embodiment is constructed by diffusively bonding the X-ray generating layer 5 and the electron beam absorbing layer 6, and further bonding the electron beam absorbing layer 6 and the heat absorbing portion 20. The target T is adapted to be rotated by a rotary shaft 21. Similar to [Example 1], the X-ray generation layer 5 is a layer that generates X-rays 4 by irradiation with the focused electron beam 1 and has a high X-ray generation efficiency and a high melting point, such as tungsten or tungsten. Molybdenum or the like is preferable.

The film thickness depends on the desired X-ray focal spot size, but about 1 μm is preferable to obtain a focal spot size of 1 μm. At this time, the beam diameter of the speed-collecting electron beam 1 needs to be focused to 1 μm or less. Since the X-ray generation layer 5 is thin, the electrons of the focused electron beam 1 irradiated cannot be absorbed by the X-ray generation layer 5.

The electron beam absorption layer 6 is a layer that absorbs the electrons of the speed-collected electron beam 1 that has passed through the X-ray generation layer 5. The electron beam absorption layer 6 is preferably a light element having a low X-ray generation efficiency. For example,
Beryllium or carbon having a small atomic number is suitable. The electron beam absorption layer 6 needs to have a thickness enough to absorb electrons, and is related to the accelerating voltage of the irradiated electrons. When the acceleration voltage is 100 kV, about 0.1 mm is required,
When the acceleration voltage is 200 kV, 0.3 mm or more is necessary.

The heat absorbing portion 20 has a function of absorbing the heat generated in the X-ray generating layer 5 by the irradiation of the speed-collecting electron beam 1, storing the heat, and radiating the heat. Therefore, the greater the heat capacity, the better
Therefore, some volume is required. The material has good thermal conductivity due to the function it should have, and has a large specific heat.
For example, carbon or the like is preferable. The irradiation of the speed-collecting electron beam 1 generates X-rays and heat in the X-ray generation layer 5, but the speed-collecting electron beam 1
The target T is rotated around the rotation shaft 21 so that the irradiation position of the target changes every moment.

As a result, the irradiation portion of the X-ray generation layer 5 by the speed-collecting electron beam 1 is prevented from locally becoming high in temperature. The generated heat is stored in the heat absorbing unit 20, gradually propagates from the heat absorbing unit 20 to the surroundings, and is dissipated. In this embodiment, the X-ray generation layer 5 shown in [Example 1] was used as a constituent element as the X-ray generation layer, but the X-ray generator described in [Example 2] and [Example 3] was used. 8 can be used.

[Embodiment 5] Next, an embodiment of the second invention will be described. FIG. 5 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. FIG. 5 shows an X-ray source [Example
The target of 1] is built in and used,
A part of an X-ray source is shown. In FIG. 5, in FIG.
Since the same reference numerals are used for the same parts, detailed description thereof will be omitted. Only new symbols will be described. 13 is a vacuum container, 14 is an X-ray extraction window, 15 is a cooling pipe, and 16 is a cooling refrigerant.

The target T is composed of a support 7 of oxygen-free copper, an electron beam absorption layer 6 of beryllium foil, and an X-ray generation layer 5 of tungsten film. Target T is a vacuum container 1
X-rays 4 are generated when the focused electron beam 1 is irradiated. The generated X-ray 4 is the X-ray extraction window 1
It is taken out from No. 4.

The X-ray extraction window 14 is preferably made of a material having a high X-ray transmittance, for example, beryllium is suitable. Also,
A cooling pipe 15 is joined to the oxygen-free copper support 7, and a cooling medium 16 flows in the cooling pipe 15. In the embodiment of FIG. 5, the support 7 and the cooling pipe 15 are joined and separated from each other, but a circulation hole is formed in the oxygen-free copper support 7 and the refrigerant 16 is introduced into the circulation hole. It can be distributed directly.

The operation of this embodiment will be described. X-ray generation layer 5
Is irradiated with the focused electron beam 1, emits X-rays 4, and generates a large amount of heat. The generated heat is transferred to the electron beam absorption layer 6 by heat conduction, and then to the support 7.
The heat conducted to the support 7 is carried outside by the refrigerant 16 in the cooling pipe 15. The same result can be obtained in a form in which the circulation holes are formed in the oxygen-free copper support 7 and the refrigerant 16 is directly circulated.

In this way, the heat of the target T is carried to the outside by the refrigerant 16 and cooled. The coolant 16 may be a conventional one, for example, water. Since the target T is cooled in this way, a focused electron beam with a large current can be irradiated, and a strong X-ray can be obtained.

[Sixth Embodiment] Next, another embodiment of the second invention will be described. FIG. 6 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. The reflection type target of [Example 1] is used for the X-ray source. 6, since the same reference numerals as those in FIG. 5 are the same parts in FIG. 6, detailed description thereof will be omitted. Only new symbols will be described. Reference numeral 17 is a cooling fan.

This embodiment will be described with reference to FIG. Target
The get T is composed of an X-ray generation layer 5 made of a tungsten film and an electron beam absorption layer 6 made of beryllium foil. The electron beam absorption layer 6 of beryllium foil is bonded to the vacuum container 13.
In this case, the case where the support 7 is omitted will be described. The X-rays 4 generated by the irradiation of the X-ray generation layer 5 with the focused electron beam 1 are extracted to the outside through the X-ray extraction window 14. The amount of heat generated at the same time is transferred to the vacuum container 1 via the electron beam absorption layer 6.
It is transmitted to 3.

The vacuum container 13 having transferred heat is cooled by the fan 17. Therefore, the X-ray generation layer 5 and the vacuum container 13
The heat drop between the
It is transmitted to 3. As a result, the target T is cooled so that it can be irradiated with a focused electron beam having a large current, and a strong X-ray can be obtained.

[Embodiment 7] Next, still another embodiment of the second invention will be described. FIG. 7 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. As the X-ray source, the reflective target of [Example 1] is used. In the figure, the same reference numerals as those in FIGS. 5 and 6 denote the same parts, and thus detailed description thereof will be omitted. Only new symbols will be described. Reference numeral 18 is an electronic cooling element.

The target T is composed of an X-ray generating layer 5 of a tungsten film, an electron beam absorbing layer 6 of beryllium foil, and a support 7 of oxygen-free copper. The target T is joined to the vacuum container 13 via an electronic cooling element 18, and the vacuum container 13 is cooled by a fan 17.

The cooling operation of this embodiment will be described. Electron beam 1
The X-rays 4 generated by the irradiation of are extracted to the outside through the X-ray extraction window 14. At the same time, the heat generated in the target T is carried to the vacuum container 13 by the function of the heat sink of the electronic cooling element 18. Since the vacuum container 13 is cooled by the fan 17, the heat drop between the target T and the vacuum container 13 becomes large, and the amount of heat generated is quickly transmitted to the vacuum container 13.
As a result, the target T is cooled so that it can be irradiated with a focused electron beam having a large current, and a strong X-ray can be obtained.

In this embodiment, since no coolant such as cooling water is used, there is no fear of water leakage accidents, and the cooling performance is excellent because the electronic cooling element is used. The target used in the above [Example 5] to [Example 7] was the target of [Example 1], but it was shown in [Example 2] to [Example 3]. Even if a target composed of an X-ray generator is used, the same result can be obtained.

[Embodiment 8] Still another embodiment of the second invention will be described. FIG. 8 is an explanatory view of a target according to still another embodiment of the present invention. FIG. 8 shows an embodiment of an X-ray source incorporating a rotating target like the embodiment 4 shown in FIG. In FIG. 8, in FIG.
Since the same reference numerals as those in 5 are the same parts, detailed description will be omitted. Only new symbols will be described. Reference numeral 21 is a rotary shaft, 24 is a rotor, 25 is a stator, and 26 is a bearing.

The target T is formed by depositing an X-ray generating layer 5 of a tungsten film having a thickness of about 1 μm on the surface of a support 7 of a conical carbon by sputtering or CVD. The support 7 made of carbon is the X-ray of the focused electron beam 1.
It has both functions of an absorption layer for electrons that have passed through the ray generating layer 5 and an endothermic portion for heat generated in the X-ray generating layer 5 by irradiation with the focused electron beam 1.

The target T is designed to be rotated by the rotary shaft 21. The rotating shaft 21 is held by a bearing 26, and has a rotor 24 and a stator 25.
It is designed to rotate at high speed. Vacuum container 13
Is the target T, the rotary shaft 21, the rotor-24,
The X-ray extraction window 14 is provided on the outer surface of the bearing 26 and the like. A light element that transmits X-rays well, for example, a beryllium plate is suitable for the X-ray extraction window 14.

The focused electron beam 1 is irradiated onto the conical slope surface, and the position of the irradiation surface changes every moment as the target T rotates. Therefore, the irradiation surface of the target T does not locally become high in temperature and a focused electron beam of a large current can be irradiated. X-ray 4 generated on the irradiation surface of the target T by the focused electron beam 1
Are extracted from the X-ray extraction window 14.

[Embodiment 9] Still another embodiment of the second invention will be described. FIG. 9 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. FIG. 9 shows an embodiment of an X-ray source incorporating the rotating target of [Embodiment 7] shown in FIG. In the figure, the same reference numerals as those in FIG. This embodiment is completely the same in principle as [Embodiment 8]. As shown in FIG. 9, in the target T, the X-ray generating layer 5 is formed by attaching a tungsten film to the end surface of the support 7 of the cylindrical carbon. Further, the target T can be rotated by the rotating shaft 21.

The rotating shaft 21 of the target T is held by a bearing 26, and is connected to the rotor 24 and the stator-2.
5 rotates at high speed. The vacuum container 13 has an X-ray extraction window 14 through which X-rays 4 generated by irradiation with the focused electron beam 1 are extracted. Rotation axis 2 of target T
1 is obliquely inclined with respect to the optical axis of the focused electron beam 1, and X
This is to make it easy to take out the wire 4.

[Embodiment 10] Still another embodiment of the second invention will be described. 10 is an explanatory view of an X-ray source of a target according to still another embodiment of the present invention, and FIG. 11 is a sectional view of the X-ray source of the target of FIG. 10 and 1
1 is an embodiment of an X-ray source incorporating the rotating target of [Embodiment 7] shown in FIG. In the figure, the same reference numerals as those in FIG.

As shown in FIG. 10, the target T is formed by depositing a tungsten film on the cylindrical surface of a cylindrical carbon support 7 to form an X-ray generating layer 5. The target T is designed to be rotated by the rotary shaft 21. The rotating shaft 21 of the target T is a bearing 2
It is held at 6 and is rotated at a high speed by the rotor 24 and the stator 25.

In the present embodiment, the optical axis of the focused electron beam 1 and the rotation axis 21 are orthogonal to each other, and therefore the focused electron beam 1 passes through the X-ray generation layer 5 on the cylindrical surface of the target T. It will be irradiated. As shown in FIG. 11, the vacuum container 13
Is provided with an X-ray extraction window 14, and the X-rays 4 generated by the irradiation of the focused electron beam 1 are extracted.

When the X-ray generation layer 5 of the tungsten film is deteriorated by the irradiation of the focused electron beam 1, the cylindrical target T is used.
Is moved in the axial direction (vertical direction in FIG. 10) so that the focused electron beam 1 is irradiated on the surface of the new X-ray generation layer 5. As a result, the number of times the target T is replaced can be reduced.

[Embodiment 11] Still another embodiment of the second invention will be described. FIG. 12 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. Since the fine focussing electron beam is used in the micro focus X-ray source, it is necessary to surely focus the electron beam on the X-ray generation layer 5 of the target T. The focus of the electron beam can be adjusted while observing the transmitted X-ray image of the sample, but when the X-ray image cannot be observed in real time, this is a very troublesome work. Therefore, another focus detection method for the electronic beam is required. In this embodiment, an X-ray source capable of detecting a focus using a scanning electron image and adjusting a fine focused electron beam to the X-ray generation layer 5 of the target T will be described.

In FIG. 12, the same reference numerals as those in FIG. 1 denote the same parts, and the description thereof will be omitted. Only new symbols will be described. 30 is a metal mesh, 31 is a filament, 3
Reference numeral 2 is an electron lens, 33 is a deflection coil, and 34 is an electron beam detector. The focused electron beam 1 generated by the filament 31 is focused by the electron lens 32 and irradiated on the target T. The target T is composed of an X-ray generation layer 5, an electron beam absorption layer 6 and a support 7.

When the focused electron beam 1 is irradiated on the target T, reflected electrons and secondary electrons are also generated at the same time when X-rays are generated. A scanning electron image is obtained by scanning the focused electron beam 1 with the deflection coil 33 and detecting backscattered electrons or secondary electrons with the electron beam detector 34. It is possible to focus by changing the exciting current of the electron lens 32 while observing the scanning electron image.

However, since the X-ray generation layer 5 has a smooth and uniform surface, it is difficult to focus the focused electron beam 1. Therefore, the metal mesh 30 is placed on the surface of the X-ray generation layer 5. Since the metal mesh is not uniform and has a difference in mass, the mesh image can be seen so that the focus can be easily grasped.

Instead of placing the metal mesh 30,
Marks for focusing may be engraved on the X-ray generation layer 5. After the focused electron beam 1 is focused on the scanning electron image, the scanning of the focused electron beam 1 is stopped, and the focused electron beam 1 is irradiated to one point to generate an X-ray to obtain a fine focus X-ray source.

[Embodiment 12] Still another embodiment of the second invention will be described. FIG. 13 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. In X-ray CT and laminography, which are one of the application fields of X-rays, an X-ray generation source whose X-ray generation point rotates may be necessary. In this embodiment, the X-axis of a fine focus is generated by the rotational deflection of the focused electron beam.
An embodiment of a reflective target for rotating the line generation point will be described.

In FIG. 13, the same symbols as those in FIGS. 1, 10 and 12 are the same parts, and the explanation thereof will be omitted. Only new symbols will be described. 40 is a vacuum pump. Target T
The structure (1) is a structure in which the electron beam absorbing layer 6 is bonded to the annular support 7 and the X-ray generator 8 is provided on the upper surface thereof.

The X-ray generator 8 has an annular shape, and the size of its cross section is equal to the desired X-ray focal spot size. The material is preferably a metal having a high X-ray generation efficiency and a high melting point in consideration of the amount of heat generated, and for example, tungsten or the like is suitable.

The electron beam absorbing layer 6 is a light element that hardly generates X-rays, and for example, beryllium is used. The thickness needs to be sufficient to absorb electrons, and for example, 0.3 mm is required when the acceleration voltage of electrons is 200 kV. The support 7 is preferably made of a metal having good thermal conductivity, for example, a copper-based metal, in order to efficiently release the heat generated by the irradiation of electrons. Further, it is conceivable that the cooling water or the electronic cooling element is used for positive cooling.

Next, the operation of this embodiment will be described. The focused electron beam 1 generated by the filament 31 is transferred to the electron lens 32.
Is focused on the X-ray generator 8 by the deflection coil 33,
X-ray 4 is generated. The focused electron beam 1 is moved by the deflection coil 33 along the X-ray generator 8 while irradiating the circular X-ray generator 8 with the focused electron beam 1. Therefore, the point that generates the X-ray rotates and moves.

Since the cross section of the X-ray generator 8 is small, a fine focus can be obtained regardless of the beam diameter of the focused electron beam 1. Further, the equipment member is provided in the vacuum container 13, and the inside thereof is held in a vacuum state by a vacuum pump 40. The generated X-rays 4 are extracted to the outside through the X-ray extraction window 14.

[Embodiment 13] Still another embodiment of the second invention will be described. FIG. 14 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. 14A is a sectional view of an X-ray source according to still another embodiment of the present invention, FIG.
FIG. 14B shows a target used in the X-ray source of FIG.
It is explanatory drawing of a get. This embodiment will explain an embodiment of an X-ray source using a transmission type target that rotates an X-ray generation point of a micro focus by rotating and deflecting a focused electron beam 1. In the figure, the same reference numerals as those in FIG. Only new symbols will be described. 42 is an airtight X-ray transparent window.

The target T has a ring-shaped X-ray generator 8 attached to an X-ray transmission window 42 for sealing off the vacuum. The X-ray transmission window 42 is preferably made of a light element that causes less X-ray generation by electron irradiation and less X-ray absorption.
For example, a beryllium thin plate or the like is suitable.

The cross-sectional size of the X-ray generator is set to be equal to the desired X-ray focal spot size, and the material is preferably a metal having a high X-ray generation efficiency and a high melting point. For example, tungsten or the like is suitable. In the present embodiment, an example is shown in which the X-ray generator 8 is arranged twice, and it is possible to select X-ray generation points having different radii of rotation.

Next, the operation of this embodiment will be described. The focused electron beam 1 generated by the filament 31 is transferred to the electron lens 32.
Is focused on the X-ray generator 8 by the deflection coil 33,
X-ray 4 is generated. The focused electron beam 1 is rotated by the deflection coil 33 along the circular X-ray generator 8 and the generation point of the X-ray 4 is rotated.

Since the cross section of the X-ray generator 8 is small, a fine focus can be obtained regardless of the beam diameter of the focused electron beam 1. The device member is provided inside the vacuum container 13 and is held in a vacuum state by a vacuum pump 40.

In the conventional X-ray source of the same kind, it was difficult to make the focused electron beam thin because of large aberration due to the rotational deflection of the focused electron beam, and it was not possible to obtain a fine focus size. However, in this embodiment, a fine focus size can be obtained by devising the structure of the X-ray generation target.

[Embodiment 14] An embodiment of the third invention will be described. FIG. 15 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. X-rays include continuous X-rays and characteristic X-rays. In the meantime, the continuous X-ray is decelerated because the focused electron beam collides with the X-ray generation target and is subjected to the Coulomb force by the electric field of the nuclei in the target material, and the path of the electron is bent. Is emitted when Therefore, the wavelength of continuous X-rays is related to the acceleration voltage of electrons. Characteristic X-rays are emitted when a high-speed electron collides with an electron in each shell surrounding the nucleus and an electron in the inner shell close to the nucleus is knocked out, and then an electron in the outer shell transits. Therefore, the wavelength of the characteristic X-ray is related to the material of the target.

Therefore, when the characteristic X-ray is used, the target is often replaced. It would be convenient if this target could be replaced easily. Referring to FIG. 15, X
An X-ray source in which the material of the X-ray generation layer can be instantaneously switched by changing the material of the X-ray generation layer depending on the location and changing the location of the irradiated X-ray generation layer by deflecting the focused electron beam will be described. .

In FIG. 15, T is a target, 1 is a focused electron beam, 4A is a characteristic X-ray, 6 is an electron beam absorbing layer, 7 is a support, 15 is a cooling pipe, 16 is a cooling refrigerant, and 33 is a cooling medium. Is a deflection coil, 35 is a first metal film, and 36 is a second metal film. The target T is obtained by bonding the electron beam absorption layer 6 of beryllium foil to the support 7 made of an oxygen-free copper plate, and further bonding the first metal film 35 and the second metal film 36 thereon. .

First metal film 35 and second metal film 36
Is an X-ray generating layer, and a material having a characteristic X-ray of a required wavelength is selected for each. The film thickness is the desired X
Although it depends on the line focus size, it is around 1 μm and can be formed by sputtering or CVD. Target T
Is cooled by flowing a refrigerant 16 through the cooling pipe 15.

The operation of this embodiment will be described. Focused electron beam 1
Is irradiated with the target T, and the characteristic X-ray 4A is emitted from the X-ray generation layer.
Generate. During this irradiation, the focused electron beam 1 is deflected by the deflection coil 33, and the irradiation position is set to the first metal film 35 or the second metal film 36, thereby changing the material of the X-ray generation layer of the target. be able to. Since the focused electron beam 1 can be instantly deflected, it can be instantly switched to characteristic X-rays having different wavelengths.

In this embodiment, the number of metal films is two, but if many types of targets are required, different numbers of metal films may be provided. Also,
As for the cooling method of the get, the cooling method by the fan shown in [Embodiment 6] and [Embodiment 7] may be used instead of flowing the refrigerant 16.

[Embodiment 15] Another embodiment of the third invention will be described. FIG. 16 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention. This example is based on [Example 1
4] is almost the same structure. In the figure, the same reference numerals as those in FIG. Reference numeral 18 is an electronic cooling element.

In this embodiment, a large number of X-ray generators 8 are provided instead of the X-ray generating layers of the first metal film 35 and the second metal film 36 of [Embodiment 14]. This embodiment is similar to [Embodiment 14] in that X that generates characteristic X-rays is used.
The material of the X-ray generation layer is changed depending on the location, and the location of deflection and irradiation of the focused electron beam is changed to instantaneously switch the material of the X-ray generation layer that generates the characteristic X-ray.

The target T is obtained by bonding the electron beam absorbing layer 6 of beryllium foil to the support 7 of an oxygen-free copper plate, and then bonding a number of X-ray generators 8 thereon. That is, the target structure shown in FIG. 2 of [Example 2] has a plurality of X-ray generators 8. In the X-ray generator 8,
It is possible to select a material that emits characteristic X-rays of the required wavelength.

When the X-ray generator 8 becomes a minute lump, a minute X-ray focal spot size can be obtained without necessarily focusing the beam diameter of the focused electron beam 1 to be small. In order to obtain a focal spot size of 1 μm, the size of each X-ray generator 8 is preferably 1 μm. Further, if the beam diameter of the focused electron beam 1 is made sufficiently thin, the area of the X-ray generator 8 may be large if the thickness of the X-ray generator 8 is reduced.

The focused electron beam 1 is irradiated by the deflection coil 33 onto the X-ray generator 8 made of a material that emits a characteristic X-ray having a desired wavelength, and a characteristic X-ray 4A having a desired wavelength is obtained. By changing the X-ray generator 8 irradiated by the focused electron beam 1, it is possible to instantly generate the characteristic X-rays 4A having different wavelengths. Further, in this embodiment, the target T is cooled by the electronic cooling element 18, but other methods may be used.

[Embodiment 16] Still another embodiment of the third invention will be described. 17 and 18 are explanatory diagrams of targets of an X-ray source according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. Only new symbols will be described. 38 is a thin film and 39 is a protective layer.

In this embodiment, the material of the thin film for generating the characteristic X-rays is changed depending on the location, and the focused electron beam is deflected.
The material of the target is instantly changed by changing the irradiation position. Although a reflective target has been described in each of the above embodiments, this embodiment is a transmissive target.

In FIG. 17, the target T is a thin film 38.
The X-ray generator 8 is mounted on the structure. Thin film 38
Is preferably a light element that causes less X-ray generation due to electron irradiation and less X-ray absorption. For example, beryllium foil is most suitable. The X-ray generator 8 may be made of a material that emits a characteristic X-ray having a required wavelength. Since the X-ray generator 8 is a minute mass, a minute X-ray focal spot size can be obtained without necessarily converging the beam diameter of the focused electron beam 1 to be small. Further, if the beam diameter of the focused electron beam 1 is made sufficiently thin and the thickness of the X-ray generator 8 is made thin, the area of the X-ray generator 8 may be large.

The focused electron beam 1 is irradiated by the deflection coil 33 onto the X-ray generator 8 made of a material that emits a characteristic X-ray having a desired wavelength, and a characteristic X-ray 4A having a desired wavelength is obtained. By changing the X-ray generator 8 with which the focused electron beam 1 is irradiated, the wavelength of the characteristic X-ray generated can be instantly changed.

FIG. 18 shows a structure in which the X-ray generator 8 is embedded between the protective layers 39 in order to prevent the X-ray generator 8 from falling over. As the protective layer, a light element that generates less X-rays is preferable. The X-ray generator 8 is mechanically protected by the protective layer 39.

[Embodiment 17] An embodiment of the fourth invention will be described. Still another embodiment of the present invention will be described. Figure 1
9 is an explanatory view of a high resolution X-ray imaging apparatus according to still another embodiment of the present invention. This embodiment relates to a high resolution X-ray imaging apparatus using the target described in each embodiment.

In FIG. 19, the same reference numerals as those in FIGS. Only new codes will be described. 40 is a vacuum pump, 43 is an accelerating tube, 44 is a condenser lens, 45 is an objective lens, 46 is a synchronizing circuit,
47a and 47b are displays, 48 is a sample, 49 is a stage, 50 is an X-ray image intensifier, 51
Is a collimator lens, 52 is a mirror, 53 is an imaging lens, 54 is a CCD camera, and 55 is a controller.

The X-ray image pickup device is roughly divided into a fine focus X-ray source, a control unit and a detection system. The micro focus X-ray source includes a filament 31, an accelerating tube 43, a condenser lens 44, a condenser lens 44, and a vacuum chamber 13 which are held in vacuum by a vacuum pump 40.
The deflection coil 33, the objective lens 45, and the target T are arranged. The target T is the embodiment of FIG.
4] has the same configuration as the target T shown in [4].

That is, the electron beam absorption layer 6 of beryllium foil is bonded to the support 7 of an oxygen-free copper plate, and the X-ray generation layer 5 of a tungsten film is vapor-deposited. A cooling pipe 15 is provided on the back surface and is cooled by a refrigerant 16 flowing therethrough. In this embodiment, the target shown in [Embodiment 4] of FIG. 4 was used, but the targets of the other embodiments described above may be used.

The control section comprises a synchronizing circuit 46 for synchronizing the deflection signal and the detection signal of the electron beam and a display 47a for displaying a scanning image of the electron beam. The detection system is an X-ray image intensifier 50 that converts X-rays into a visible image, and outputs the X-ray image intensifier 50 from a CCD.
Lens sets 51 and 52 for forming an image on the camera 54, and the C
It comprises a display 47b for displaying the output of the CD camera 54.

Next, the function of this embodiment will be described. The focused electron beam 1 is generated from the filament 31 and is accelerated by the accelerating tube 43, and the condenser lens 44 and the objective lens 45.
It is focused by the function of the two lenses. Filament 3
No. 1 is preferably a high-luminance lanthanum hexaboride filament for obtaining a focused electron beam with a large current. The reason why the number of the lenses is two is to narrow the focused electron beam 1 finely, and one or three or more lenses may be arranged as needed so long as a desired beam diameter can be obtained. Absent.

In order to obtain an X-ray fluoroscopic image with a resolution of 1 μm, the electron beam diameter must be 1 μm or less. Also, X
The thickness of the line generation layer 5 also needs to be 1 μm or less. The focused electron beam 1 irradiates the deflection coil 33 while scanning the surface of the X-ray generation layer 5. By this irradiation, the X-ray generation layer 5
The reflected electrons and secondary electrons generated from the electron beam detector 34
Detected by.

The synchronizing circuit 46 synchronizes the deflection signal for driving the deflection coil 33 with the detection signal of the electron beam detector 34,
A scanning electron image is obtained and displayed on the display 47a. The focused electron beam 1 is focused on the X-ray generation layer 5 while observing the scanning electron image displayed on the display 47a.

In this case, as shown in [Embodiment 7] of FIG. 7, when a mesh is placed on the X-ray generation layer 5, the focus is easily adjusted. After focusing, the focused electron beam 1 stops the deflection by the deflection coil 33 and irradiates one point on the X-ray generation layer 5 to generate X-rays 4. The X-rays 4 are extracted to the outside through the X-ray extraction window 14.

The X-ray source thus obtained has a small source diameter and a fine focus, so that penetrative blurring does not occur in the transmission image of the sample and the X-ray source has a high resolution. A fluoroscopic image is obtained. When the target T is damaged by the irradiation of the focused electron beam 1, the irradiation position of the focused electron beam 1 is slightly shifted by the deflection coil 33. With this,
The life of the get T can be extended and the number of times of replacement can be reduced.

The sample 48 is placed on the stage 49 and placed at a predetermined position between the X-ray generating layer 5 and the X-ray image intensifier 50, and the X-ray is irradiated from the microfocus X-ray source. Receive. The X-ray transmitted through the sample 48 is converted into a visible image by the X-ray image intensifier 50. An output image of the X-ray image intensifier 50 is formed on a CCD camera 54 by a collimator lens 51 and an imaging lens 53. The formed sample image is displayed on the display 47b.

A mirror 52 is provided between the collimator lens 51 and the imaging lens 53, and the detection system can be downsized by bending the optical path. As the CCD camera 54, it is optimal to use a cooled CCD camera capable of long-time exposure in terms of sensitivity and dynamic range. The CCD camera 54 is controlled by the controller 55 and displays the detected image on the display 47. The X-ray imaging unit may be a detection system other than the combination of the X-ray image intensifier 50 and the CCD camera, but this combination system has high sensitivity and is easy to use.

[0108]

As described above in detail, according to the present invention, firstly, it has an advantage of good cooling property, and
It is possible to provide an X-ray generation target having a small X-ray generation region. Secondly, it is possible to provide an X-ray source that can obtain high-power X-rays using the above target. Thirdly, in an X-ray source that outputs characteristic X-rays, it is possible to provide an X-ray source that can easily and quickly change the wavelength by changing the material of the target. Fourthly, it is possible to provide a high resolution X-ray imaging device using the above X-ray source.

[Brief description of drawings]

FIG. 1 is a sectional view of a reflective target according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a reflective target according to another embodiment of the present invention.

FIG. 3 is a reflection type target according to still another embodiment of the present invention.
It is sectional drawing of Get.

FIG. 4 is a reflection type target according to still another embodiment of the present invention.
It is sectional drawing of Get.

FIG. 5 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 6 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 7 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 8 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 9 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 10 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

11 is a cross-sectional view of the X-ray source of FIG.

FIG. 12 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 13 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 14 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 15 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 16 is an explanatory diagram of an X-ray source according to still another embodiment of the present invention.

FIG. 17 is an explanatory diagram of a target of an X-ray source according to still another embodiment of the present invention.

FIG. 18 is an explanatory diagram of a target of an X-ray source according to still another embodiment of the present invention.

FIG. 19 is a high resolution X according to still another embodiment of the present invention.
It is an explanatory view of a line imaging device.

FIG. 20 is a cross-sectional view of a conventional transmission type thin film target.

[Explanation of symbols]

 T target 1 Focused electron beam 4 X-ray 5 X-ray generation layer 6 Electron beam absorption layer 7 Support 8 X-ray generator 13 Vacuum container 14 X-ray extraction window, 15 Cooling pipe 16 Refrigerant 17 Cooling fan 18 Electron Cooling element 20 Endothermic part 21 Rotating shaft 24 Rotor 25 Stator 26 Bearing 31 Filament 32 Electron lens 33 Deflection coil 34 Electron beam detector 40 Vacuum pump 42 Airtight X-ray transmission window 43 Accelerator tube 44 Condenser lens 45 Objective Lens 46 Synchronous circuit 47a, 47b Display 48 Sample 49 Stage 50 X-ray image intensifier 51 Collimator lens 52 Mirror 53 Imaging lens 54 CCD camera 55 Controller

Claims (19)

[Claims] 1. An X-ray generator comprising an X-ray generating layer having a thin thickness which does not absorb an irradiated electron beam and an electron beam absorbing layer which absorbs electrons transmitted through the X-ray generating layer. Target. 2. The X-ray generating target according to claim 1, wherein the X-ray generating layer is made of a plurality of materials. 3. A target for X-ray generation, comprising an X-ray generator for generating X-rays having a minute focus, and an electron beam absorbing layer for absorbing electrons transmitted through the X-ray generator. get. 4. The target for X-ray generation according to claim 3, wherein the X-ray generator comprises at least one. 5. The target for X-ray generation according to claim 3, wherein the X-ray generator is made of a plurality of materials. 6. The target for X-ray generation according to claim 1, wherein the electron beam absorbing layer is supported by a metal support. 7. The electron beam absorption layer is formed by bonding a beryllium foil to a copper-based metal plate, and the X-ray generation layer is a reflection type formed by depositing a tungsten film on the electron beam absorption layer of the beryllium foil. 7. The X-ray generation target according to claim 6. 8. A reflection type X-ray generating target comprising an X-ray generating layer having a thin thickness which does not absorb an irradiated electron beam and an electron beam absorbing layer which absorbs electrons transmitted through the X-ray generating layer. An X-ray source having a get and means for cooling the target from the electron beam absorbing layer side, and configured to extract X-rays from the X-ray generating layer side. 9. The X-ray source according to claim 8, wherein the X-ray generating target has an electron beam absorbing layer supported by a support. 10. The X-ray source according to claim 8, wherein the means for cooling the X-ray generating target from the electron beam absorbing layer side is constituted by an electronic cooling element. 11. A target for X-ray generation, comprising a thin X-ray generating layer that does not absorb irradiated electron beams and an electron beam absorbing layer that absorbs electrons transmitted through the X-ray generating layer. An X-ray source comprising: a means for rotating the target. 12. An X-ray generation target comprising an X-ray generator for generating X-rays having a minute focus and an electron beam absorbing layer for absorbing electrons transmitted through the X-ray generator, and the target. An X-ray source, characterized in that it comprises means for rotating the get. 13. An electron beam deflecting means, an X-ray generating target, and means for detecting reflected electrons and secondary electrons from the target, the electron beam being detected by a scanning image by the detecting means. X-ray source having means for adjusting the focal point of the target to the target. 14. The X-ray source according to claim 13, wherein the X-ray generation target is provided with an electron beam focusing mesh at its X-ray generation site. 15. The X-ray source according to claim 13, wherein the X-ray generation target is provided with a surface pattern for focusing an electron beam at the X-ray generation site. 16. An electron beam having means for deflecting and rotating and scanning an electron beam, and an X-ray generating target having an annular X-ray generator, said means for rotating and scanning the electron beam. The X-ray source is configured to rotate and scan the X-ray generating point on the X-ray generator. 17. A means for deflecting an electron beam, and an X-ray generating target comprising an X-ray generator made of a plurality of materials, wherein the means for deflecting the electron beam is applied to the target. Characteristic X that changes the irradiation position of the electron beam to generate
An X-ray source characterized in that it is configured to switch the lines. 18. An electron beam deflecting means and an X-ray generating target having an X-ray generating layer made of a plurality of materials are provided, and an electron for the target is deflected by the electron beam deflecting means. An X-ray source characterized in that the irradiation position of the X-ray is changed to switch the generated characteristic X-ray. 19. An X-ray generating target having a thin X-ray generating layer which does not absorb an irradiated electron beam and an electron beam absorbing layer which absorbs electrons transmitted through the X-ray generating layer. An X-ray source for irradiating the target with a fine electron beam to extract X-rays from the X-ray generation layer side and cooling from the electron beam absorption layer side, and an X-ray image transparent to the sample are displayed. X-ray image intensifier and cooled CCD
An X-ray imaging apparatus comprising a detection system including a camera.