JPH0592999U - Accelerator tube - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an accelerating tube that protects the inner wall of the ring-shaped insulator 2 from damage and can be used economically and stably for a long period of time. [Structure] Inside a ring-shaped insulator 2, a removable insulating shield ring 7 is installed so as to be supported by a mounting ring 4 for mounting the acceleration electrode 1, for example.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is used for, for example, an ion implanter, an electron beam accelerator, etc., and relates to an accelerator tube for accelerating charged particles such as ions and electrons extracted from a charged particle source.

[0002]

[Prior Art]

 FIG. 4 is a partial cross-sectional view showing a schematic configuration of a conventional acceleration tube of this type. In this accelerating tube, a ring-shaped accelerating electrode 1 is arranged in a desired number of stages via a ring-shaped insulating material 2 made of, for example, ceramic, and flange portions 3 are provided at both ends thereof, respectively. A high DC voltage is applied to the accelerating electrode 1 from an accelerating power source (not shown), and charged particles extracted from a charged particle source installed in a high potential portion (not shown), for example, an ion beam 6 is disposed in the ground potential portion. It accelerates toward the room. In the figure, 4 is a mounting ring for mounting the accelerating electrode 1, and 5 is a corona ring provided at the tip of the mounting ring 4. Further, although not shown, a voltage sharing resistor is connected between each acceleration electrode 1-1.

[0003]

[Problems to be solved by the device]

 However, in the accelerating tube as described above, when the ion beam 6 passes through the inside of the accelerating tube, for example, the accelerating electrode 1 is sputtered, and various floating substances including conductive substances are attached to the inner wall of the ring-shaped insulator 2. And get soiled. If this contamination progresses, for example, the insulation between the acceleration electrodes 1-1 becomes unbearable, which may lead to dielectric breakdown.

Further, since the adhered matter adheres to the inner wall of the ring-shaped insulator 2 in such a state that it soaks in, it is extremely difficult to wipe it off normally in such a state. Therefore, if the pollution is severe, the ring-shaped insulator 2 cannot be regenerated, and the entire accelerating tube must be replaced, which is extremely uneconomical.

Therefore, the main object of the present invention is to provide an accelerating tube that protects the inner wall of the ring-shaped insulator from contamination and can be used economically and stably for a long period of time.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the acceleration tube of the present invention is characterized in that a detachable insulating shield ring is installed inside the ring-shaped insulator as described above.

[0007]

[Action]

 According to the above configuration, even if the accelerating electrode is sputtered by the passage of the ion beam and various floating substances including conductive substances are generated in the accelerating tube, the inner wall of the ring-shaped insulator is covered with the insulating shield ring. Therefore, the floating material does not adhere to the inner wall of the ring-shaped insulator and stain the inner wall.

The floating substance adheres to the detachable insulating shield ring and contaminates it. However, the acceleration pipe is inspected at regular intervals to check the contamination state. It is possible to remove only the insulation shield ring and replace it with a new one.

The removed insulating shield ring can be separately cleaned and prepared for reuse, depending on the stain condition. Since this cleaning can be performed by taking it out from the inside of the accelerating pipe, the work is extremely easy, and the operation of the accelerating pipe is not hindered.

[0010]

【Example】

 FIG. 1 is a schematic partial sectional view showing an accelerating tube according to an embodiment of the present invention. In addition, the same reference numerals as those in the conventional example of FIG. 4 indicate the same or corresponding parts. In the following, differences from the conventional example will be mainly described.

In this embodiment, an insulating shield ring 7 made of an insulating material such as ceramic or plastic resin and configured to be removable is supported by a mounting ring 4 for mounting the acceleration electrode 1, for example. In this way, the interiors of the ring-shaped insulators 2 are respectively installed.

As the detachable insulating shield ring 7, for example, as shown in FIG. 2, two or more (three in the illustrated example) ring pieces 8 are made of an insulating material such as ceramics. And the stepped steps 81-81 have a mating structure, and each ring piece 8 is configured to be integrally fastened by a fastener 9 such as a screw, and each ring piece 8 is divided. In this state, the insulating shield ring 7 may be formed by putting the insulating shield ring 7 in the ring-shaped insulator 2 described above.

According to the above configuration, even if the accelerating electrode 1 is sputtered by the passage of the ion beam 6 and various floating substances including conductive substances are generated in the accelerating tube, the inner wall of the ring-shaped insulator 2 is Since it is covered with the insulating shield ring 7, the floating matter does not adhere to the inner wall of the ring-shaped insulator 2 and the inner wall is contaminated.

Then, the suspended matter adheres to the inside of the removable insulating shield ring 7 and stains it. This is caused by inspecting the accelerating pipe at regular intervals such as regular inspection, and checking each insulating shield ring 7 Check the contamination status of No. 3, and if the contamination is severe, remove the insulation shield ring 7 only and replace it with a new one.

Further, the removed insulating shield ring 7 can be separately cleaned and prepared for reuse, depending on the stain condition. Since this cleaning can be performed by taking it out from the inside of the accelerating tube, the work is extremely easy, and it is very convenient because it does not interfere with the operation of the accelerating tube.

FIG. 3 is a perspective view showing another example of the detachable insulating shield ring 7. In this example, a ring-shaped insulator such as plastic resin having excellent elasticity is used, and one step is cut to form a stepped step portion 82, and the stepped portion 82 has an insulating shield. The outer shape of the ring 7 may be slightly contracted, the insulating shield ring 7 may be put in the ring-shaped insulator 2 in this state, and then the insulating shield ring 7 may be returned to the original ring shape.

According to this example, the fastener 9 as in the example of FIG. 2 is not necessary, and its attachment and detachment are easy, which is convenient.

[0018]

[Effect of the device]

 As described above, according to the present invention, the detachable insulating shield ring is installed inside the ring-shaped insulator to protect the inner wall of the ring-shaped insulator from being soiled, and the insulation shield ring is also soiled. Only the one needs to be replaced, and it has a practical effect that the life of this type of acceleration tube can be extended very economically.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view showing an accelerating tube according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of an insulating shield ring used in the present invention.

FIG. 3 is a perspective view showing another example of the insulating shield ring used in the present invention.

FIG. 4 is a partial cross-sectional view showing a schematic configuration of a conventional acceleration tube.

[Explanation of symbols]

 1 Accelerating electrode 2 Ring-shaped insulator 3 Flange 7 Insulation shield ring

Claims (1)

[Scope of utility model registration request] 1. An accelerating tube comprising a plurality of ring-shaped accelerating electrodes for accelerating charged particles extracted from a charged particle source, arranged in a plurality of stages with ring-shaped insulators, and flanges provided at both ends thereof. An accelerating tube characterized in that a removable insulating shield ring is provided inside the ring-shaped insulator.