JP2605839Y2 - Insulated column of charged particle accelerator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated column for insulating and supporting an accelerating tube in a charged particle accelerating apparatus, equipment for a DC high voltage section, and the like.

[0002]

2. Description of the Related Art A charged particle accelerator has a high rigidity and a high dielectric strength in order to hold a portion located at a high potential portion of various devices installed in a high voltage portion, an accelerating tube and the like. For example, an insulating column made of a resin plate such as acrylic or polyacetal is used. As shown in the sectional view of FIG. 2 for the acceleration tube section of the charged particle accelerator, for example, the acceleration tube 1 has an acceleration electrode 2 having a beam passage opening at the center and an insulator 3 for insulatingly supporting the acceleration electrodes of each stage.
An insulating column 4 is provided on a side portion of the accelerating tube, and the column is disposed between the ground portion and the high voltage portion along the accelerating tube, and a high potential terminal of the accelerating tube is provided. Are supported using insulating columns.

The insulating column 4 is formed of an insulating plate. When a voltage is applied to the insulating plate in accordance with the arrangement of the insulating plate between the ground portion and the high-voltage portion, electric charges are accumulated, and the insulating plate is insulated. Due to a slight difference in the surface state of the electrodes, imbalance occurs in the potential distribution on the surface, and creeping discharge occurs. Therefore, the insulating column 4 is configured to fix the potential at appropriate intervals.

FIG. 3A is a front view of an insulating column, and FIG. 3B is a cross-sectional view taken along line AA of FIG. 3A. It is constructed by mounting divided feeder electrodes 6 which are shorter than the width of the plate and are distributed at intervals. The divided feeder electrodes 6 which are positioned back to back with the insulating plate 5 interposed therebetween are electrically connected by bolts to the insulating plate. A potential is given by dividing the voltage between the voltage parts by a resistor.

[0005]

As described above, by applying a potential to each of the divided feeder electrodes 6 of the insulating column 4, it is possible to prevent the occurrence of an unbalanced state of potential sharing on the column surface. When an abnormal discharge occurs in the accelerating tube located in the column, an excessive voltage is transiently applied between the divided feeder electrodes, and discharge may occur between the electrodes. Generally, the discharge at this time occurs between the ends of the divided feed electrode 6 where the maximum electric field occurs, and as a result, a discharge occurs on the surface of the insulating plate 3 between the electrode ends. When such creeping discharge occurs, the surface of the insulating plate 4 is melted, and the discharge is damaged, and the creeping dielectric strength of the insulating column decreases,
Thereafter, discharge becomes easier.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a charged particle accelerator in a charged particle accelerator in which a discharge between divided feed electrodes does not affect the surface dielectric strength of the insulating column.

[0007]

In order to achieve the above object, the present invention provides a charged particle accelerator having an insulated plate having divided feeder electrodes on both sides of an insulating plate. The present invention is characterized in that both ends of the feeder electrode protrude from side edges of the insulating plate.

[0008]

When the discharge occurs between the divided feed electrodes of the insulating column, the discharge remains at the end of the electrode protruding from the side edge of the insulating plate and does not lead to the surface discharge of the insulating plate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1A is a front view of an insulating column, and FIG. 1B is a cross-sectional view taken along line AA of FIG. On both sides of the insulating plate 5 in the insulating column 4, divided feeder electrodes 6 are mounted in a distributed manner at intervals. The divided feeder electrodes 6 positioned back to back with the insulating plate 5 therebetween are electrically connected by bolts attached to the insulating plate. Each split feeder electrode 6 is longer than the width of the insulating plate 5 and Both ends protrude from side edges of the insulating plate.

The length L of the projecting portion of the divided feeder electrode 6
Is determined in consideration of the width of the electrode and the thickness of the insulating plate 3. In this way, by protruding both ends of each divided feeder electrode 6 from the side end of the insulating plate, the maximum electric field concentration portion of the adjacent split feeder electrode can be separated from the surface of the insulating plate 5. Therefore, even when a discharge occurs between adjacent divided feeder electrodes, the discharge remains only in the space between the electrodes and in the gas-insulated space, does not shift to the creeping discharge of the insulating plate 5, and does not damage the insulating plate surface. .

[0011]

According to the present invention, as described above, even when a discharge occurs between the divided feeder electrodes, a creeping discharge of the insulating plate that causes irreparable damage to the solid insulating plate occurs. Therefore, even if a discharge occurs in the insulating column, the discharge remains only in the space between the electrodes and does not lower the creeping dielectric strength of the insulating plate. Is restored to a state where the dielectric strength of the substrate is maintained.

[Brief description of the drawings]

FIG. 1 is a front view and a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of an arrangement state of insulating columns.

FIG. 3 is a front view and a sectional view of a conventional insulating column.

[Explanation of symbols]

 4 Insulation column 5 Insulation plate 6 Split feeder electrode

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05H 5/03 H05H 7/00 H05H 9/00

Claims (1)

(57) [Scope of request for utility model registration] 1. In an insulating column of a charged particle accelerator in which divided feeder electrodes are provided on both sides of an insulating plate at intervals, both ends of the split feeder electrode protrude from side edges of the insulating plate. An insulating column, characterized in that: