JPS61185844A - X-ray electron tube having input face for exciting x-ray and input face thereof - Google Patents

Abstract

PURPOSE:To obtain an input face for exciting X-ray having considerably improved resolution and an electron tube having such input face by providing a fiber glass plate comprised of clad section for reflecting the light and core section for passing the light and an input fluorescent face composed of alkali halide phosphor material crystal pole. CONSTITUTION:The substrate or fiber glass plate 3 is comprised of a clad section 4 for reflecting the light and plural core sections 5 for passing the light where the core section 5 is projected from X-ray incident face side 6 and provided with an input fluorescent face. The input fluorescent face 7 is constructed with alkali halide CsI phosphor material crystal pole 8 and light shield/reflection film 9 formed at the core section 5, and upon incident of X-ray, it is converted into the light through CsI phosphor material crystal pole 8. Said light is reflected efficiently by the crystal pole 8, especially by said film 9 then transmitted through the core section 5 onto X-ray image tube to provide resolution approximately same with the fineness of the core section 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an X-ray excitation input surface suitable for use in an X-ray image tube or an X-ray image pickup tube, and an X-ray electron tube having this input surface.

[Background technology and its problems]

General! = When performing X-ray imaging using an X-ray image tube, a low-quality X-ray source is used to image a minute object, but with a conventional X-ray image tube, the X-ray image is The input phosphor surface that converts the image controller is inside the vacuum vessel, so the x-rays must pass through the outer wall of the vacuum vessel before reaching the input fluorescein surface. The outer wall of the vacuum container is heat resistant as an X-ray image tube, does not release gas, and can withstand atmospheric pressure.
It is composed of glass and metals such as aluminum and titanium. Therefore, low-quality X-rays are largely absorbed by this outer wall, and the number of X-rays reaching the input phosphor surface is greatly reduced, resulting in poor sensitivity.

Therefore, as proposed in Japanese Patent Application Laid-Open No. 55-3101, there is a method in which the input fluorescent surface is disposed outside the vacuum container. In this system, as shown in FIG. 4, the substrate on the input surface of the X-ray image tube is formed of fibers with a lath grade 1, and an input fluorescent surface 2 is formed thereon. However, the X-ray absorption rate of this input fluorescent surface 2 is relatively low, so in order to sufficiently absorb X-rays and exhibit sufficient sensitivity, the thickness of the input fluorescent surface 2 must be from several tens of μm to several hundred μm. thickness.

However, now, in order to see minute changes in the structure of an object that are around 10 μm in size, an input surface that can resolve several μm is required.
The most common fiberglass plates produced at present are those with a diameter of phi and p-diameter of a μm (7), so there are some that have sufficient performance as the fiberglass plate 1 of the substrate on the input surface.

However, as mentioned earlier, if the input fluorescent surface is thick, from several tens of micrometers to several hundred micrometers, the light will be diffused within it, resulting in poor resolution, making it impossible to use it for the above-mentioned purposes. Can not.

[Purpose of the invention]

The object of the present invention is to provide an input surface for X-ray excitation with significantly improved resolution and an electron tube for X-rays having this input surface.

[Summary of the invention]

This invention provides a fiber glass plate comprising a cladding portion that reflects light, a core portion through which light passes through the cladding portion and having one end protruding; (An input surface for X-ray excitation comprising two input phosphor surfaces made of formed alkaline pallite phosphor columnar crystals.

The present invention also provides a fiberglass plate comprising a cladding portion that reflects light and a plurality of core portions that pass through the cladding portion and having one end protruding from the cladding portion; (
This is an electron tube for X-rays having an input surface for excitation of X-rays.

[Embodiments of the invention]

As mentioned above, in the conventional example, the fiberglass plate of the input surface board is made of a solid body of sufficiently fine fibers to prevent light diffusion, so the input fluorescent surface formed on it is the fiberglass plate. Due to the lack of a light guide effect with the fineness of

Therefore, the input surface for X-ray excitation of this invention is shown in FIG.
As shown in FIG. 5 and the surface is the same figure (
As shown in bl, it is an assembly of light guides/p-beams consisting of a core part 5 and a cladding part 4. Furthermore, as is clear from the same figure (al), one end of the fiber glass grating 3, that is, the X-ray entrance surface side 6, has the core portion 5 protruding as described above, and a fluorescent surface 7 (two-man force) is provided above it. It is being

This input fluorescent surface 7 is as shown in the same figure (aJ).
A protruding core portion 5ζ2 is formed of an alkali halide such as a C8I phosphor columnar crystal 8, and a light shielding/reflecting film 9 made of aluminum or the like is deposited on the outside of the CSRI phosphor columnar crystal 8, particularly on the X-ray incident side. It is composed of

Next, a method of manufacturing an input surface for X-ray excitation according to the present invention will be explained. First, photon cysts are applied to the side of the fiberglass plate 3 from which the core portion 5 is projected, and exposed from the opposite side. Thereafter, when the unexposed photoresist is washed away, a periphery in which the photoresist is coated only on the core portion 5 is formed. Next, this surface is chemically etched by approximately several μm. When the photoresist is then removed, a fiber glass grate 3 is formed which serves as a substrate with one end of the core portion 5 protruding. Next, C3I is vacuum deposited on this fiberglass plate 3.

First, put the fiber lath plate 3 into a vacuum evaporator, create a sufficient vacuum, and then add some water-free gas, such as N!
Add gas to, for example, about 10 TOrr. When C8I is deposited in this atmosphere, columnar crystals of C5I with a diameter of 10 μm grow, and these columnar crystals are formed above the protruding core portion 5 or in wide valleys. The second columnar crystal has a length of several tens of μm to several hundred μm, and is set to a length that sufficiently absorbs the X-rays used. In order to reduce the leakage of light from the columnar crystals and to speed up the light guide, a thin layer of aluminum, for example, is deposited on this surface as a light shielding/reflecting film 9.

Next, an X-ray electron tube, for example an X-ray image tube, having the X-ray excitation input surface of the above invention will be described.

That is, as shown in FIG. 2, the input surface 11 is attached to the opening C: of the vacuum container 10 having a cylindrical shape with two bottoms. This input surface 11 is a feature of the present invention, and is composed of the fiber glass grating 3 and the input fluorescent surface 7 as described above, but since it has already been described in detail, the description thereof will be omitted. Incidentally, since the C3I phosphor columnar crystal 8 of the input phosphor surface 7 is very sensitive to moisture, the input phosphor surface 7 is covered with an airtight cover 12 to prevent moisture. Further, at the inner rear part of the vacuum vessel 1θ, an anode 13 and a dual-output fluorescent surface 14 are provided.

During operation, incident X-rays are absorbed by the C8I phosphor columnar crystal 8 and converted into light. Much of this light is reflected on the surface of the C3I phosphor columnar crystal 8, and is particularly efficiently reflected at the portion where the light shielding/reflection film 9 is formed, and guided to the core portion 5 of the fiber glass grate 3. Core part 5
It transmits the image of the see light inside the X-ray image tube through the X-ray image tube.

Since the C8I phosphor columnar crystal 8 does not extend over a plurality of core parts 5, the CSX phosphor columnar crystal 8 is several tens of μm thick.
Even if it is as long as several hundred μm from m, a resolution close to the fineness of the core portion 5 of the fiber glass grade 3 can be obtained, and therefore an X-ray image tube with very high resolution can be obtained.

[Modified example of the invention]

In the above embodiment, an X-ray image tube was used as an example of an X-ray electron tube, but the present invention can also be applied to an X-ray image pickup tube as shown in FIG. The same parts as in the above embodiment are given the same reference numerals, and detailed explanation will be omitted.

〔Effect of the invention〕

According to this invention, the C3I vapor-deposited phosphor is deposited on the surface of the fiber glass plate 3 from which the core portion 5 with a diameter of several μm protrudes, in an atmosphere containing a slight amount of gas that does not contain water. The columnar crystals 8 form the core part 5 and the wide part of the valley (
: completed, therefore, the columnar crystals 8 do not extend over the plurality of core parts 5. As a result, the fineness of the distribution of the core portion 5 changes the X-ray image into a light image, and even if the columnar crystals 8 are long enough in such an atmosphere, each columnar crystal 8 is independent. In addition, an input fluorescent surface 7 which sufficiently absorbs X-rays and has high sensitivity can be obtained. As a result, a highly sensitive and high resolution X-ray image tube or X-ray image pickup tube can be obtained.

[Brief explanation of the drawing]

FIG. 1 (al (bl) is a cross-sectional view showing an input surface for X-ray excitation according to an embodiment of the present invention, and a plan view showing a fiber glass plate constituting this input surface for X-ray excitation. X having an input surface for X-ray excitation according to an embodiment of the invention
3 is a cross-sectional view showing an X-ray electron tube (X-ray image tube) that is a modification of the present invention; FIG. 4 is a cross-sectional view showing a conventional X-ray image tube. FIG. 3... Fiber glass plate, 4... Clad part, 5... Core part, 7... Input fluorescent surface, 8... C
5I fluorescent columnar crystal, 9... light shielding 1 reflective film, 11.
...Input surface. Applicant's representative Patent attorney Takehiko Suzue Figure 1 (a) (b) Figure 2 1t'it'lN"77L-I+λRiki 1st revision IJ
Figure 3 Figure 4

Claims (2)

[Claims] (1) A fiber glass plate consisting of a clad part that reflects light and a core part that passes through the clad part and has one end protruding, and is formed in the protruding core part of this fiber glass plate. 1. An input surface for X-ray excitation, comprising: an input phosphor surface made of columnar crystals of aruralihalide phosphor. (2) A fiber glass plate comprising a cladding portion that reflects light and a plurality of core portions that pass through the cladding portion and having one end protruding, and the protruding core portion of the fiberglass plate. An X-ray electron tube having an input surface for X-ray excitation, comprising at least an input surface for X-ray excitation constituted by an input phosphor surface made of columnar crystals of an alularihalide phosphor formed in .