JPS63281335A - Discharge tube for z pinch - Google Patents

Abstract

PURPOSE:To generate the uniform discharge breakdown on the periphery of an air column without using the discharge breakdown on the surface of an insulator and prevent the deterioration of the insulator by making the gap at the peripheral section of mating disk-shaped electrodes shorter than that at the center section and providing loophole-shaped grooves on the periphery of the disk electrode. CONSTITUTION:A discharge container is made of coaxial double cylinders, mating disk-shaped electrodes are formed with the bottom section 2 of an outside container 1 and the end section 4 of an inside container 3, and the inside and outside containers are partitioned with an insulator 5. At least one of mating electrodes 2, 4 has an edge 6 on its periphery, and loophole-shaped grooves 7 are provided on at least one edge 6. The edge 6 is provided on the peripheral section of one of the mating disk-shaped electrodes, the electric field at the peripheral section is made larger than that at other portions, thus the electric discharge is started between the electrodes at the peripheral section, the loophole-shaped grooves 7 are provided on the edge of at least one electrode, thus the uniform discharge breakdown can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray source using a Z Vinci Glazma, and particularly to an electrode shape suitable for obtaining good initial discharge breakdown.

[Conventional technology]

The basic structure of the Z-pinch consists of a cylindrical discharge vessel with opposing disk electrodes. When this discharge tube is subjected to high-speed, large-current discharge, the following phenomenon occurs.

As voltage is applied, discharge breakdown occurs at the periphery of the cylindrical air column.
It is assumed that a cylindrical thin current layer is formed. An electromagnetic force in the axial direction is generated by the circumferential magnetic field and the axial current induced by this current layer, and one cylindrical current layer moves toward the axis.

Particles inside the current layer are absorbed into the current layer and turn into plasma. The plasma eventually pinches on the axis to form a high-density plasma. On the other hand, plasma is heated by Joule heating due to discharge current and adiabatic compression, and becomes high temperature.

X-rays are generated from this high-temperature, high-density plasma.

The problem with Z-pinch discharge tubes is how to form a cylindrical initial current layer with a uniform circumference. The conventional device is described in Journal of Physical Society of Japan, Vol. 52, No. 10, (1983), p. 3425 (
Journal of the physical So
Society of Japan, Vol, 52.4
10. (1983).

PP, 3425), a creeping discharge on the surface of a cylindrical insulator at the base of the electrode was used.

[Problem that the invention seeks to solve]

The conventional technique uses creeping discharge of a cylindrical insulator for initial cylindrical discharge breakdown, and since the discharge results in a large current, deterioration of the insulator cannot be ignored. An object of the present invention is to cause uniform discharge breakdown at the periphery of an air column without using discharge breakdown along the surface of an insulator.

[Means for solving problems]

The purpose of the above is to shorten the gap between the peripheral edges of the opposing disc-shaped electrodes compared to the center to facilitate discharge breakdown at the peripheral edges, and at the same time to create crenelated edges on the disc electrodes in order to achieve uniform discharge breakdown. This is achieved by cutting a groove in the

[Effect]

The opposing disk-shaped electrodes are provided with edges on their peripheries so that the electric field at the periphery is larger than at other parts. This allows discharge to start between the electrodes at the peripheral edge, and by cutting crenel-like grooves in at least one of the electrode edges, it is possible to obtain uniform discharge destruction.

〔Example〕

Two embodiments of the present invention will be described below with reference to FIG.

The discharge vessel is composed of a coaxial double cylinder, and the bottom 2 of the outer vessel 1 and the end 4 of the inner vessel 3 form opposing disc-shaped electrodes. An insulator 5 partitions the inner and outer containers. At least one of the counter electrodes 2.4 has an edge 6 on its periphery.
have. Furthermore, at least one edge 6 has crenelated grooves 7.
is cut.

A low pressure gas is sealed inside the discharge vessel. The container is connected to a power supply capacitor 9 via a switch 8.

The operation will be explained below. When the switch 8 is turned on, the charging voltage of the capacitor 9 is applied between the inner and outer containers.

In the conventional method, creeping discharge on the surface of the insulator 5 was used. In the present invention, an edge 6 is provided at the peripheral edge between the opposing electrodes.

FIG. 2 shows the results of calculating equipotential lines when a voltage is applied to the discharge vessel structure shown in FIG. 1. If the distance between the edges 6 of the periphery of the counter electrode 2.4 is appropriately narrowed, the electric field therebetween can be made smaller than in other parts, and discharge breakdown can be caused selectively between the edges 6. In order to ensure that discharge breakdown occurs on the edges, the edges of the electrodes 2 and 4 are always configured with corners.

However, if the peripheral edge is flat along the circumference, discharge breakdown will not necessarily occur uniformly around the circumference. In other words, if the discharge tube is manufactured completely in the shape of a shaft, uniform discharge destruction can occur, but
As a practical matter, the presence of slight non-uniformity causes local discharge breakdown to occur over time.

In order to solve this problem, crenel-shaped grooves 7 may be provided on at least one of the edges 6 of the counter electrode (usually on the edge on the inner electrode 4 side). FIG. 3 shows the calculated equipotential lines between the edges 6 when the grooves 7 are provided. By providing the groove, the equipotential line also squeezes into the groove, thereby increasing the electric field at the p-corner. As a result.

The non-uniformity caused by the embrasure structure outweighs the non-constraint of discharge determined by the degree of machining and manufacturing of the pipe, and discharge breakdown occurs selectively at the corners of the embrasure.

Even if discharge breakdown occurs at one location on the periphery and the interelectrode voltage begins to drop, the electric field at the corner of the crenelation is large, so discharge breakdown will occur at other corners with almost no delay, and the entire circumference will suffer. Discharge breakdown occurs. The resulting destructive discharge area becomes bamboo-shaped depending on the number of crenels.

As the plasma diffuses, it develops into a uniform radiation radius while the current progresses. The pitch of the grooves in the crenelation structure is preferably approximately 10 m in consideration of the spread of the current, and the depth of the grooves may be approximately 80% or more of the width of the grooves.

〔Effect of the invention〕

According to the present invention, since discharge breakdown on the surface of the insulator is not used, deterioration of the insulator can be avoided.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a discharge vessel according to an embodiment of the present invention, and FIG.
The figure is an equipotential distribution diagram between the inner and outer electrodes, and FIG. 3 is an equipotential distribution diagram between the electrodes when a crenelation structure is provided at the electrode periphery. 1... Outer discharge vessel, 2... Disk shape at the bottom of the outer discharge vessel 1! Pole, 3... Inner discharge vessel, 4... Disc-shaped electrode on the end face of the inner discharge vessel, 5... Insulator, 6... Edge of the periphery of the opposing disc-shaped electrode, 7... Crenellation structure Groove, 8...
switch. 9...Power supply capacitor.

Claims (1)

[Claims] 1. In a Z-pinch discharge tube that consists of opposing disc-shaped electrodes and is intended to cause initial discharge breakdown at the periphery of the disc electrode, an edge is provided at the periphery of at least one of the opposing disc electrodes. A discharge tube for a Z-pinch, characterized in that a crenellated groove is provided on at least one of the edges.