JPH03222250A - X-ray generation device - Google Patents

Abstract

PURPOSE:To efficiently cool a target by making the sectional thickness of the target of the part located rather on the base member side than the electron irradiation part thicker than the section thickness of the target in the electron irradiation part. CONSTITUTION:The sectional thickness of a target 1 of the part located rather on the base member 3 side than the electron irradiation part 19 is made thicker than the sectional thickness of the target 1 in the electron irradiation part 19. Heat generated in the electron irradiation part 1a of the target 1 travels in the inside of the target 1 by heat transfer to be transferred to the base member 3, however, since the thickness of a target 1b of the part located on the base member 3 side than the electron irradiation part 1a is made thicker than the thickness of the electron irradiation part 1a, an amount of heat to be transferred inside the target 1 becomes big. Thereby, the target can be cooled efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an X-ray generator used in an X-ray instrument such as an X-ray diffraction device. In particular, the present invention relates to an X-ray generation device that generates X-rays from a sparse portion by applying electrons to an electron irradiation portion of a target mounted on a base member.

[Prior Art] The above-mentioned X-ray generator is a type of X-ray generator in which electrons generated from an electron generating means such as a filament collide with a target made of metal such as copper or molybdenum, and X-rays are generated from the target. something is known. In this type of X-ray generator, a very small portion of the energy of electrons colliding with the target becomes X-rays, and most of the remaining energy is transferred into the target as heat. Therefore, if high-energy X-rays are to be continuously generated for a long time, it is necessary to cool the target.

As a conventional X-ray generating device, the devices shown in FIGS. 11 and 12 are known. In this X-ray generator, a cylindrical target 51 is fitted into a base member 53 via an O-ring 52.

As shown in FIG. 12, the lower end of the tubular body 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 X-rays are emitted from the target 51. The emitted X-rays are extracted to the outside through an X-ray extraction window 57 made of an X-ray transparent material such as beryllium and provided at an appropriate location in the tube body 55 at an appropriate extraction angle.

The following water passages are provided inside the base member 53. That is, a water receiving port 58 provided at the right end of the base member 53, a first communicating path 59°, and a cross-shaped spout 6 provided at the center of the base member 53 (see FIG. 11).
0, a second communicating path 61° and a water passageway that runs from the drain port 62. Cooling water flows through this water passage in the direction of the arrow.
The target 51 is cooled from the back side.

[Problems to be Solved by the Invention] In the conventional apparatus described above, the thickness of the target 51 was uniform, as can be seen from FIG.

Therefore, cooling of the target 51 has been performed exclusively by cooling water flowing through the above-mentioned water passage. However, cooling with this cooling water alone does not provide a sufficient cooling effect, and therefore, in the conventional X-ray generator, it was not possible to apply very high power to the filament 54. For example, 50kv -20m
A was the limit. For this reason, there was a limit to the output of X-rays that could be obtained.

Furthermore, in the conventional apparatus described above, turbulence tends to occur in the cooling water spouted from the spout 60, and therefore, the heat of the target 51 cannot be efficiently removed by the cooling water in some cases.

The present invention has been made in view of the above-mentioned problems in conventional devices, and is an X-ray device that cools a target extremely efficiently and, as a result, makes it possible to obtain high-output X-rays.
The purpose of the present invention is to provide a line generating device.

[Means for Solving the Problems] In order to achieve the above object, the X-ray generator according to claim 1 has a cross-sectional thickness of the target in a portion closer to the base member than the electron irradiation section. It is characterized by being thicker than the cross-sectional thickness of the target at the section.

An X-ray generator according to a second aspect of the present invention is characterized in that the outer peripheral surface of the target is provided with a tapered surface that is inclined so as to widen from the electron irradiation section toward the base member.

The X-ray generator according to the third aspect is characterized in that a flange is formed integrally with the target, and the target is fixed on the base member with the flange in contact with the base member.

In the X-ray generator according to claim 4, a recess for spraying cooling water onto the target is formed on the back side of the electron irradiation section, and an end portion of the recess on the electron irradiation section side is provided with a recess for spraying cooling water onto the target. It is characterized by a tapered surface that tapers toward the surface.

In the X-ray generator according to claim 5, a recess for spraying cooling water onto the target is formed on the back side of the electron irradiation section, and a recess for guiding the flow of the cooling water is provided on the inner circumferential side of the recess. It is characterized by an uneven shape.

The uneven shape may be a linear groove extending from the electron irradiation part of the target toward the base member, or a linear fin (feather member). Moreover, it can also be made into a spiral groove.

In the X-ray generator according to claim 6, the cross-sectional thickness of the target in a portion closer to the base member than the electron irradiation part is thicker than the cross-sectional thickness of the target in the electron irradiation part,
Moreover, the target is characterized in that a tapered surface is provided on the outer peripheral surface of the target so as to widen from the electron irradiation section toward the base member.

[Function] In the X-ray generator of claim 1 (Figs. 1 and 2), the heat generated in the electron irradiation part (1a) of the target (1) causes the inside of the target (1) to The heat is transferred to the base member (3) by conduction. In this case, the thickness of the target (1b) in the portion closer to the base member (3) than the electron irradiation part (1a) is
Since it is thicker than the thickness of target (1)
) The amount of heat transmitted within the target (1) is very large, so the target (1) can be efficiently cooled.

In the X-ray generator of the second aspect (FIG. 3), since the tapered surface (22) is provided on the outer peripheral surface of the target (21), turbulence occurs in the heat flowing through the target (21) by conduction. Therefore, more heat can be sent from the electron irradiation part (21a) of the target to the base member (3).

In the X-ray generator of claim 3 (FIG. 5), the heat generated in the target (31) is transferred to the target (31).
It flows into the base member (3) via a flange (32) formed integrally with the base member (3). Flange (32) and base member (
Since the contact area with base member (3) is large, the amount of heat flowing into base member (3) is even greater.

In the X-ray generator (FIG. 7) of the fourth aspect, a tapered surface (42) is formed at the upper part of the recess (47) for spraying cooling water formed on the back side of the electron irradiation part (41a). The cooling water sprayed onto the back side of the electron irradiation section (41a) flows down along the tapered surface (42). The provision of the tapered surface (42) prevents turbulence from occurring in the cooling water flowing down. This allows the cooling water to remove more heat generated in the target (4 pieces).

In the X-ray generating device (FIGS. 8 to 10) according to the fifth aspect, the cooling water sprayed onto the target (31) is cooled by the uneven shape ( It flows down along the straight grooves 23, straight fins 24, and spiral grooves 25). Therefore, generation of turbulence during the flow is prevented.

In the X-ray generator (FIG. 3) of the sixth aspect, the cross-sectional thickness of the target (21) is increased and at the same time, a tapered surface (22) is provided on the outer peripheral surface of the target (21). By combining both of these features, we can increase the amount of heat transmitted within the target (1), rectify the flow, and transfer more heat to the electron irradiation section (21a).
).

[Example 1] FIG. 1 shows an example (first example) of an X-ray generator according to the invention of claim 1. In this embodiment, the target 1 is attached onto the base member 3 via an O-ring 15 for stopping water.

The target 1 has a cylindrical shape, and its bottom surface is fixed to the base member 3 by fastening means such as bolts. A tube body 5 is attached via a vacuum O-ring 16 onto the base member 3 to which the target 1 is fixed. Like the target 1, this tube body 5 is also fixed to the base member 3 by fastening means such as bolts.

FIG. 2 shows the assembled state of each of the above members. As shown in the figure, the tube body 5 is fitted onto the outer peripheral side surface of the target 1. Further, a cylindrical cooling water spouting portion 2 projecting upward from the base member 3 is housed in a cylindrical recess 17 provided in the center of the target 1 . The pipe body 5 is provided with a water supply channel 18 and a drainage channel 19, and the water supply channel 18 communicates with the water receiving port 8 of the base member 3.
A drainage channel 19 communicates with the drainage groove 12 of the base member 3. In this way, a cooling water passage is formed by the pipe supply channel 18, the base water inlet 8, the base water channel 9, the cooling water spout 2, the base drainage groove 12, and the pipe drainage channel 19.

Since this embodiment is configured as described above, the electrons ejected from the filament 4 provided in the vacuum chamber 6 formed by the tube body 5 collide with the electron irradiation part 1a of the target 1. And X-rays are generated from there. The generated X-rays are extracted to the outside through an X-ray extraction window 7 (indicated by a broken line) provided at a suitable location on the side surface of the tube body 5.

While the target 1 is being irradiated with electrons, the tube body supply channel 1
The cooling water sent from 8 is sent to the cooling water spout 2 via the base water inlet 8 and the base water channel 9, and a cross-shaped spout 10 is formed at the top of the spout 2.
The electron beam is sprayed onto the back surface of the target 1, particularly on the back surface of the electron irradiation section 1a. The target 1 is cooled by the cooling water sprayed in this manner. The cooling water used for cooling the target 1 is then discharged to the tube body drainage channel 19 via the base drainage channel 12.

The thickness of the electron irradiation part 1a of the target 1 is relatively thin so that the heat generated outside can be reliably taken away by the cooling water, but the thickness is such that it can withstand the water pressure of the cooling water, e.g. The thickness is approximately 2 mm. Further, the thickness of a portion closer to the base member 3 than the electron irradiation portion 1a, for example, the portion 1b in the figure, that is, the cross-sectional thickness is greater than the thickness of the electron irradiation portion 1a. In this way, by increasing the thickness of the target 1, the heat generated in the target 1 is not only directly taken away from the electron irradiation section 1a by the cooling water, but also transmitted through the target 1 to the base member 3. It is also taken away from. In this way, cooling is not performed simply by using cooling water, but also by utilizing heat conduction through the target 1, so that cooling efficiency is greatly improved. As a result, the voltage and current applied to the filament 4 can be increased more than ever before, making it possible to extract high-output X-rays.

FIG. 3 shows an embodiment (second embodiment) of the X-ray generator according to claims 2 and 6. The difference between this embodiment and the first embodiment shown in FIGS. 1 and 2 is that, as shown in FIG. This is because a tapered surface 22 is provided which is inclined so as to widen.

Other points are the same as those in the second embodiment, and the same members are given the same reference numerals and their explanations will be omitted.

In the first embodiment shown in FIG. 2, the thickness of the target 1 is increased to improve the heat conduction of the target 1, thereby increasing the cooling efficiency of the target 1. however,
Since the top A of this target 1 has a right-angled shape, there is a possibility that a phenomenon of heat accumulation may occur at the top A, making it impossible to obtain sufficient heat conduction. On the other hand, according to this embodiment (FIG. 3) in which the tapered surface 22 is formed on the top A, the above-mentioned heat accumulation is eliminated, and the heat generated in the electron irradiation section 21a is efficiently transferred to the base member. As a result, the cooling efficiency of the target 21 is further improved.

Note that, in this embodiment, the features of providing the tapered surface 22 on the upper outer peripheral surface of the target 21 and increasing the cross-sectional thickness of the target 21 on the base member 3 side are combined. Regarding the invention of Target 2
It is not an essential requirement to increase the cross-sectional thickness of the base member 3 side of the base member 1 .

FIG. 5 shows an embodiment (third embodiment) of an X-ray generator according to the third aspect of the invention. This embodiment is different from the second embodiment shown in FIG. 3, as shown in FIG.
The entire bottom surface of this flange 31 is attached to the base member 3.
The target 31 and the base member 3 are coupled to each other in a state where they are in contact with each other. In order to ensure the flow of cooling water, this flange 32 is provided with a water supply opening 33 that connects the pipe body water supply channel 18 and the base water inlet 8 and a drainage opening 34 that connects the base drain channel 12 and the pipe body drain channel 19. It is being

In this way, by providing the flange 32 integrally with the target 31 and joining it to the base member 3, heat conduction from the target 31 to the base member 3 becomes even better, and the target 31 can be removed more quickly and reliably. It is now possible to cool down.

The third embodiment shown in FIG. 5 corresponds to the second embodiment shown in FIG. 3 in which a flange is provided at the bottom of the target 21. It may be provided at the bottom of the target 1 (target without a tapered surface on the outer periphery) in one embodiment.

FIG. 7 shows an embodiment (fourth embodiment) of an X-ray generator according to the invention of claim 4. This embodiment differs from the other embodiments described so far in that the target 4
A recess 47 for cooling water spray formed inside 1
This means that changes have been made to the . That is, a tapered surface 42 is formed in the upper part of the recess 47 and is tapered upward.

The recess 17 in the first embodiment described so far, for example, in the first embodiment shown in FIG. It's at a right angle. If the upper end corner of the recess is in an acute angle state as described above, the cooling water jetted out from the cooling water spout 10 becomes turbulent at the acute corner B, and the flow of cooling water in that part is poor. There is a risk that heat may accumulate.

On the other hand, according to the target recess 47 according to this embodiment in which the taper 42 is formed at the upper end, the cooling water jetted from the jet port 10 flows onto the inner circumferential surface of the recess 47 without becoming a turbulent flow. It will surely flow down along the line. Therefore, generation of heat accumulation due to turbulent flow of cooling water can be prevented, and the cooling efficiency of the target 41 can be further improved.

8 to 10 show an embodiment of the X-ray generator according to the fifth aspect of the invention. These embodiments have a recess for spraying cooling water on the back surface of the target, for example, a fifth
This is a modification of the reference numeral 17 in the figure.

First, in the embodiment shown in FIG. 8, on the inner peripheral surface of the recess 17,
A plurality of grooves 23 are provided that extend in the vertical direction. 9th
In the embodiment shown in the figure, a plurality of fins 24 are formed instead of the grooves 23 described above. moreover,! 10
In the embodiment shown in the figure, the groove 23 or the fin 24
A spiral groove 25 is formed instead. These grooves 23, fins 248 and spiral grooves 25 are formed on the target 31.
The concave and convex shape acts as a guide for the downward flow of cooling water sprayed onto the internal ceiling surface. Cooling water flows through these grooves 23, 25 or fins 24.
Since the water flows down along the same direction, turbulence does not occur, and therefore cooling can be performed very efficiently. In particular, when the spiral groove 25 is formed, the contact area between the cooling water and the target 31 increases, so that the cooling efficiency is further improved.

Although the present invention has been described above using the embodiments shown in the drawings, the present invention is not limited to these embodiments.

[Effects of the Invention] According to the invention of claim 1, the amount of heat conduction of the target, that is, the amount of heat that can flow into the target, can be increased, so that the heat generated in the electron irradiation part of the target can be efficiently used. It is now possible to feed the target well into the base member and cool the target quickly and reliably.

According to the invention of claim 2, by providing the target with a tapered surface, formation of an acute angle part in the target is avoided, thereby preventing generation of turbulent flow in the heat flowing inside the target. There is. This prevents a decrease in cooling efficiency caused by turbulent flow of cooling water.
It is now possible to cool the target quickly and reliably.

According to the third aspect of the present invention, a large amount of heat is transferred through the contact surface between the flange and the base member, so that the target can be cooled quickly and reliably.

According to the fourth aspect of the invention, since the concave portion formed on the back side of the target for spraying cooling water is provided with a tapered surface, the cooling water sprayed on the back side of the target, that is, the ceiling surface of the concave portion, The cooling water flows down along the tapered surface without turbulence, and as a result, it is possible to prevent a decrease in cooling efficiency caused by turbulence in the flow of cooling water.

According to the invention of claim 5, similarly to the invention of claim 4, the uneven shape provided on the inner peripheral side surface of the recess prevents the flow of cooling water from being disturbed, and as a result, the cooling efficiency is improved. The decline can be prevented.

According to the invention of claim 6, by combining increasing the cross-sectional thickness of the target (invention of claim 1) and providing a tapered surface on the outer peripheral surface of the target (invention of claim 2), This makes it possible to cool the target even more quickly and reliably.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of the first embodiment of the X-ray generator according to the present invention, FIG. 2 is a side sectional view of the first embodiment, and FIG. 3 is an exploded perspective view of the first embodiment of the X-ray generator according to the present invention. 4 is a perspective view of the target in the second embodiment, FIG. 5 is a side sectional view of the third embodiment of the X-ray generator according to the present invention, and FIG. FIG. 7 is an exploded perspective view of the third embodiment, and FIG. 7 is a side sectional view of the fourth embodiment of the X-ray generator according to the present invention.
10 are side sectional views showing modified examples of the target of the X-ray generator according to the present invention, and FIGS. 11 and 12 are views showing an example of the conventional X-ray generator. 1.21, 31, 41...Target, la, 21a
, 31a, 41a - electron irradiation part of target, 1b
...Wide cross section of target, 2...Cooling water spout, 3...Base member, O...Cooling water spout, F, 47...Concavity, 22...Tapered surface, 23... Straight groove, 24... Fin,
25... Spiral groove, 32... Flange,
42...Tenoku surface, Fig. 4, Fig. 5, Fig. 8, Fig. 7, Fig. 8, Fig. 10, Fig. 11, Fig. 12

Claims (6)

[Claims] (1) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. . An X-ray generator, wherein a cross-sectional thickness of the target at a portion closer to the base member than the electron irradiation section is thicker than a cross-sectional thickness of the target at the electron irradiation section. (2) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. . An X-ray generator, characterized in that an outer circumferential surface of the target is provided with a tapered surface that is inclined so as to widen from the electron irradiation section toward the base member. (3) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. An X-ray generator characterized in that a flange is formed integrally with the target, and the target is fixed on the base member with the flange in contact with the base member. (4) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. , A recess for spraying cooling water onto the electron irradiation section is formed on the back side of the electron irradiation section, and the end of the recess on the electron irradiation section side has a groove facing toward the electron irradiation section. An X-ray generator characterized in that a tapered surface is formed. (5) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. , A recess is formed on the back side of the electron irradiation section for spraying cooling water onto the target, and an uneven shape is formed on the inner circumferential side of the recess to guide the flow of the cooling water. An X-ray generator characterized by: (6) In an X-ray generator that applies electrons to an electron irradiation part of a target mounted on a base member to generate X-rays from the part, and cools the target by applying cooling water to the electron irradiation part. , the cross-sectional thickness of the target at a portion closer to the base member than the electron irradiation section is thicker than the cross-section thickness of the target at the electron irradiation section, and furthermore, the cross-sectional thickness of the target from the electron irradiation section to the base member is thicker than the cross-sectional thickness of the target at the electron irradiation section. An X-ray generator characterized by having a tapered surface that is inclined so as to widen toward the member side.