JPS6044800B2 - Short circuit device for charged particle accelerator - Google Patents

Description

[Detailed description of the invention] The present invention relates to a short circuit device for a charged particle accelerator.

Generally, a charged particle accelerator (hereinafter referred to as an accelerator) is housed in a container filled with an insulating gas or the like, and a plurality of shield hoops are provided outside the accelerating tube to alleviate the electric field.

These shield hoops are electrically connected to the accelerating electrodes of each stage so as to have the same potential. By the way, the accelerator is operated at a voltage lower than the maximum rating.
The number of stages of i-speed electrodes is reduced to obtain the desired beam amount.

That is, for example, when the maximum rating of an accelerator is 500 KV and 50 mA and the number of acceleration stages is 10, the acceleration voltage per stage is 50 KV. When using this at 400 KV) 50 mA, the acceleration voltage per stage must be 50 KV to obtain the desired beam amount, so the number of acceleration stages must be adjusted to 8 stages. Conventionally, a short circuit device as shown in FIG. 1 has been used as a short circuit device for adjusting the number of acceleration stages.

That is, in the figure, 1 is an accelerating tube, 2 is a shield hoop provided corresponding to an accelerating electrode (not shown) and electrically connected to the accelerating electrode so as to have the same potential, and 3 is a shield hoop that is electrically connected to the accelerating electrode (not shown). It is a container. A shorting rod 4 is operated from the outside of the container 3. A shorting contact 5 is provided at the tip of the rod 4, and the other end is connected to the lowest potential portion of the accelerator tube 1. Therefore, when the shorting rod 4 is pushed in the direction of arrow A to connect the contactor 5 to the shield hoop 2 in the middle stage, the acceleration electrodes in the shield hoop 2 in the middle stage and below, that is, in the corresponding stage and below, are accelerated. Since the potential at the lowest stage of the tube 1 is applied directly or indirectly through a voltage dividing resistor (not shown), the number of acceleration stages is reduced and the number of stages can be adjusted. Note that G is an insulating gas.
However, in the short-circuit device configured in this way, the short-circuit rod protrudes from the outside, which may cause problems in the arrangement of the power supply, control panel, etc. that are incidental equipment of the accelerator.
Also, the operability is not good. In the case where only one shorting device is provided as shown in the figure, the number of shorting stages is fixed, and this type of device lacks flexibility in use. Of course, it is not preferable to provide multiple shorting devices because of the problems in arrangement and operation described above. Furthermore, as accelerators become high-voltage and large-capacity devices, the high-voltage power supply is built around the accelerator tube due to insulation problems. This is not a good thing in terms of insulation.
The present invention aims to solve the above-mentioned problems all at once, and it is possible to freely set the number of shorting steps using one shorting device, and also to create a compact shorting device that does not have any problems in installation or operation. The purpose is to obtain equipment.

The present invention will be explained based on an embodiment shown in FIGS. 2 and 3.

Reference numeral 6 denotes a drive shaft made of a threaded insulator, and is provided between the acceleration tube 1 and the shield hoop 2 of the same potential of the acceleration electrode 7 of the acceleration tube 1. The motor 8, such as a step motor 1, rotates forward and reverse. It is configured so that it can rotate in either direction.

Reference numeral 9 denotes a slide block whose planar shape is as shown in FIG. 3, for example.

That is, a screw body 91 having a screw is provided approximately in the center thereof so as to be screwed into the screw of the drive shaft 9, and both of the screw bodies 91 are provided.
A guide portion 92 having a slide bearing or the like is provided on the side. This guide portion 92 is inserted into a guide shaft 10 made of an insulator and established in parallel with the drive shaft 6 . Therefore, when the drive shaft 6 is rotated by the motor 8, the slide block 9 moves upward or downward. Reference numeral 11 denotes a contact provided on the slide block 9, which comes into contact with and separates from the shield hoop 2 as the slide block 9 moves up and down.

In this case, if the contactor 11 is made of a flexible metal such as a spring, contact with the shield hoop 2 can be ensured.
Reference numeral 12 denotes a short-circuit conductor, which can be freely wound by a conductor winder 13 provided below.

In order to be able to freely wind or unroll the slide block 9 as it moves up and down, it is preferable to form the shorting conductor 12 with a metal plate such as phosphor bronze. Note that the short-circuited conductor 12 may be freely wound by interlocking the conductor winding machine 13 and the motor 8. In the short circuit device configured in this way, the contactor 11, slide block 9, drive shaft 6, motor 8,
Since the short-circuiting conductor 12 and the like are all housed within the container 3, there is no protruding portion outside the container, the device is compact, and there are no problems with arrangement with other incidental equipment.

Since the slide block 9 having the contactor 11 moves up and down due to the rotation of the drive shaft 6 driven by the motor 8, it can come into contact with any shield hoop 2 by appropriately adjusting the rotation speed and direction of the motor 8. Since the connection with the child 11 can be made, the number of short circuit stages can be set much more freely and finely than in the past. Furthermore, even in a high-voltage, large-capacity accelerator that stores a high-voltage power source in a container, it has extremely great effects, such as eliminating problems with insulation between the grounding device and the high-voltage power source.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a conventional device, FIG. 2 is an embodiment of the present invention, FIG. 2a is a front sectional view showing the main parts of the shorting device, and FIG. FIG. 3 is a side sectional view showing the main parts of the slide block, and FIG. 3 is a plan view showing the shape of the slide block. 1... Accelerator tube, 2... Shield hoop, 3... Container, 6... Drive shaft, 7...
・Acceleration voltage, 8...Motor, 9...
Slide block, 11... Contact, 12...
...Short conductor.

Claims (1)

[Claims] 1 A drive shaft that is provided between an accelerating tube housed in a container and a shield hoop having the same potential as the accelerating electrode of the accelerating tube and is driven by a motor; Charged particle acceleration characterized by comprising: a slide block equipped with a contact that moves and comes into contact with and separates from the shield hoop; and a short-circuit conductor that is electrically connected to the contact and can be wound and rolled. Equipment short circuit device.