JP2744839B2 - High voltage power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high-voltage power supply device in which the cause of discharge is eliminated.

[Prior art] In an electron beam apparatus such as an electron microscope and an electron beam welding apparatus, and an ion beam apparatus such as an ion beam processing apparatus,
Since electrons or ions accelerated at a high voltage of several KV or several KV or more are used, a high voltage power supply is required.

For example, taking an electron microscope as an example, as shown in FIG. 2, a high-voltage power supply 1 composed of a circuit for boosting and rectifying, for example, an oscillator, a Cockcroft circuit, a transformer and a filter circuit, and supporting the tank 2 Installed on stand 3
A high voltage power supply having an insulating gas such as freon gas in the tank is used. Reference numerals 4a, 4b, 4c, and 4d denote ring-shaped electric field relaxation members for suppressing the occurrence of corona discharge, 5 denotes an insulating gas introduction tube, 6 denotes a high-voltage extraction terminal, and 7 denotes a column.

[Problems to be Solved by the Invention] When the insulating gas is charged into the tank, the gas supply pipe of the gas cylinder and the insulating gas introduction pipe 5 of the tank 2 are connected. At this time, the pressure of the insulating gas is reduced. And is usually stored in a gas cylinder.
Is extremely smaller than the internal volume of the tank 2, the flow rate of the insulating gas flowing from the gas cylinder into the tank is extremely high. Therefore, the insulating gas cools the surrounding gas under the influence of the adiabatic expansion to form water droplets, and adheres to the electric field relaxation member. Due to the adhesion, the electric field on the surface of the electric field relaxation body becomes unstable, which causes a discharge (corona discharge). At this time, oil and carbon contained in the insulating gas also adhere to the electric field relaxation body together with the water-dropped gas, which again causes a discharge (corona discharge).

The present invention is intended to solve such a problem.

[Means for Solving the Problems] For this purpose, the high-voltage power supply device of the present invention is configured such that the outlet of a pipe for introducing an insulating gas into the tank is located below the support base. .

Embodiment FIG. 1 is a schematic diagram of a high-voltage power supply device showing an embodiment of the present invention.

In the figure, components having the same numbers as those used in FIG. 2 are the same components.

In the figure, reference numeral 5 'denotes an insulating gas introducing pipe whose length is such that its outlet is located substantially below the center of the lower surface of the support base 3. Reference numeral 8 denotes a heat insulating sheet made of a heat insulating material, which is attached to the lower surface of the support base.

In such a high-voltage power supply device, when the insulating gas is charged into the tank 2, the gas supply pipe of the gas cylinder (not shown) is connected to one end of the insulating gas introduction pipe 5 of the tank 2. At this time, the insulating gas is spouted from the outlet of the insulating gas introduction pipe 5 toward the lower surface of the support base at a high speed, and the blown insulating gas hits the heat insulating sheet 8 on the lower surface of the support base and is supported therefrom. It blows up in the direction of the high voltage power supply 1 through the space between the table 3 and the side surface of the tank 2. Therefore, the speed of the insulating gas ejected from the outlet of the insulating gas introduction pipe 5 at a high speed is significantly reduced when passing through the space between the support base 3 and the side of the tank, and extremely increases in the direction of the high-voltage power supply 1. Blows at a slow speed. Accordingly, since the insulating gas does not form water droplets above the support 3, water droplets of the insulating gas and oil and carbon contained in the insulating gas adhere to the electric field relaxation members 4 a, 4 b, 4 c, and 4 d. Nothing to do. Further, since the heat insulating sheet 8 is attached to the lower surface of the support table, the lower surface of the support table is not directly cooled by the insulating gas spouted from the outlet of the insulating gas introducing pipe 5 at a high speed. Water droplets do not adhere to the lower surface of the support.

The present invention is applicable not only to a high-voltage power supply for an electron microscope but also to other high-voltage power supplies such as an electron beam device and an ion beam device.

[Effects of the Invention] In the present invention, since the outlet of the insulating gas introduction pipe of the tank is located below the support for the high-voltage power supply,
The insulating gas does not form water droplets above the support, that is, on the high voltage power supply side. Therefore, water droplets of the insulating gas and oil and carbon contained in the insulating gas do not adhere to the electric field buffer. For this reason, it is possible to prevent a discharge (corona discharge) generated when water or droplets of the insulating gas or oil or carbon contained in the insulating gas adheres to the electric field relaxation member.

[Brief description of the drawings]

FIG. 1 is a schematic view of a high-voltage power supply showing one embodiment of the present invention, and FIG. 2 is a schematic view of a conventional high-voltage power supply. 1: High voltage power supply, 2: Tank, 3: Support base 4a, 4b, 4c: Electric field alleviator, 5, 5 ': Insulating gas introduction tube, 6: High voltage extraction terminal, 7: Support, 8: Insulation sheet

Claims (1)

(57) [Claims] 1. A high-voltage power supply device comprising a tank in which a high-voltage power supply covered with an electric field relaxation body is provided on an internal support base and insulated with an insulating gas, for introducing the insulating gas into the tank. A high-voltage power supply device wherein the outlet of the tube is located below the support base.