JPS6226877A - Metal vapor laser oscillation tube - Google Patents

Abstract

PURPOSE:To prevent an abnormal discharge at a tip part, form the normal discharge plasma, and reduce the damage of electrodes, by covering the tips of the anode and cathode with the ring made of material excellent in insulating characteristics and heat resistance, and providing only the tip part with insula tion capability. CONSTITUTION:A stepped ring 22, one end of which has an outer diameter slightly smaller than the inner diameter of a ceramic inner tube 1, and the other end of which has an outer diameter slightly smaller than the inner diameter of electrodes 5 and 6, is arranged on the tip part of anode 5 and cathode 6. Said ring 22 is made of material excellent in insulating characteristics and heat resistance, for example, ceramics, quartz glass, etc. Thus the tip parts of the electrodes 5 and 6 are covered with the insulator, so that the local discharge does not occur, a normal discharge generates, while local overheat is prevented, and the possible damage of electrodes is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a metal vapor laser oscillation tube, and in particular to an abnormal number '?' from an iIt pole tip. 11.Regarding the structure for preventing.

[Technical background of the invention and its problems]

Conventional metal vapor laser oscillation tubes use metals such as molybdenum for the electrodes to discharge metal vapor within the ceramic inner tube, and the electrodes are formed in a cylindrical shape with an edge-shaped tip. However, there were drawbacks such as localized discharge, making it impossible to obtain normal discharge plasma, and only the tip of the electrode being locally hot, resulting in a short electrode life.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal vapor laser oscillation tube that eliminates the drawbacks of the prior art as described above and can prevent abnormal discharge by providing insulation only to the tip of the electrode.

[Summary of the invention]

The present invention has been made to achieve the above object, and includes supplying a discharge buffer gas into a ceramic inner tube in which metal particles are arranged, and a high voltage between an anode and a cathode provided at both ends of the ceramic inner tube. In the laser oscillation tube, the metal particles are vaporized by forming a reverse discharge plasma by applying a full voltage, and the four vaporized gold particles are excited by the free '6 atoms in the full discharge plasma to perform laser oscillation. The tips of the anode and the cathode are covered with a ring made of a material with excellent insulation and heat resistance, such as ceramic, or are coated with a coating material, so that only the tips of the electrodes have insulation properties. It is a steam laser oscillation tube.

[Embodiments of the invention]

Examples of the present invention will be described in detail below.

The metal vapor laser oscillation tube of the present invention, which is suitable for use in isotope separation technology using a laser for metallic uranium, has a structure as shown in FIG. In FIG. 1, l is a ceramic inner tube with excellent heat resistance, and a discharge buffer gas such as He I/CNe is supplied from a gas supply system 3 to a discharge section 2 inside the tube, and is exhausted by a rotary pump 4. , the voltage applied from the pulse high voltage power supply 7 between the anode 5 and the cathode 6 is several KV to 10-odd KV, and the repetition frequency is several KH.
By applying a pulsed high voltage of 100 kHz to 10-odd KHz, a complete Norsunipolar discharge is carried out and plasma is entirely generated. Metal particles 8 are placed inside the ceramic inner tube 1, and the metal particles 8 contact the discharge plasma and heat the ceramic inner tube 1 to an extremely high temperature, which evaporates the metal particles 8, thereby creating a laser medium. Metal vapor is generated. This metal vapor is uniformly distributed in the ceramic inner tube 1 at 1014 to 1015 n/c!
R3 density and excited by free electrons in the discharge plasma, the light with a wavelength specific to the metal is passed through the entire light emitting replenisher window 9 and connected to the output mirrors 10 placed at both ends of the ceramic inner tube 1. The light is amplified by an optical resonator formed by the reflecting mirror 11, and is output as a laser beam from the output mirror 10 side.

The ceramic inner tube 1 is supported at both ends by an outer tube 14 via an O-ring 12 and a bellows 13, and the space between the outer tube 14 and the inner tube 1 is evacuated by a rotary pump 15 to form a vacuum insulation chamber 16. It becomes. This vacuum insulation chamber 16
A heat shield plate 17 is provided inside. In addition, the outer tube 14
A cooling pipe 18 is provided around the . moreover,
An insulating tube 19 is inserted in the middle of the outer tube 14 to electrically isolate the anode 5 side and the cathode 6 side. In order to stably maintain the inside of the ceramic inner tube 1 at a high temperature, a vacuum insulation structure is adopted.

The temperature of the ceramic inner tube 1 rises to about 1500° C., so that linear expansion occurs due to the heat. The bellows 13 is intended to provide a degree of freedom in the movement of the ceramic inner tube 1 in the tube axis direction and absorb all of this linear expansion.

Next, the detailed structure of the electrode section 23, which is the main part of the metal vapor laser oscillation tube according to one embodiment of the present invention, is shown in FIG.

In Figure 2, the tips of the anode 5 and cathode 6 are stepped with one end having an outer diameter slightly smaller than the inner diameter of the ceramic inner tube 1 and the other end having an outer diameter slightly smaller than the inner diameter of the electrodes 5 and 6. A ring 22 is arranged. This ring 22 is made of a material with good insulation and heat resistance, such as ceramic or quartz glass. By arranging the ring 22 in this manner, the tips of the electrodes 5 and 6 are coated with an insulating material, and no local discharge occurs therefrom, and normal discharge occurs. Also, local overheating is avoided and damage to the electrodes is reduced.

Furthermore, since the temperature inside the ceramic inner tube 1 is raised to about 1500° C., the electrodes 5 and 6 expand due to the heat.

At this time, the ring 22 is pushed by the electrodes 5 and 6 and moves toward the center of the ceramic inner tube 1. When the apparatus is subsequently stopped, the electric poles 5 and 6 will contract, but the ring 22 will not move from its position. Therefore, the tips of the electrodes 5 and 6 may come off the ring 22 and be exposed. Alternatively, the length may be set to allow for the expansion of 6, or the coating material 24 of an insulating material such as ceramic may be entirely applied to the ring-shaped insulating material as shown in FIG.

[Effects of the Invention] As described above, according to the present invention, abnormal discharge at the tips of the anode 5 and cathode 6 is prevented, normal discharge plasma is formed, and damage to the electrodes is reduced. A metal vapor laser tube can be provided.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional configuration diagram of a metal vapor laser oscillation tube according to an embodiment of the present invention, Fig. 2 is a sectional view of the main part showing details of the main part of the same embodiment, and Fig. 3 is a cross-sectional view showing the details of the main part of the same embodiment. FIG. 3 is a cross-sectional view of main parts when applied.

Claims (1)

[Claims] A discharge buffer gas is supplied into the ceramic inner tube in which metal particles are placed, and a high voltage is applied between the anode and cathode provided at both ends of the ceramic inner tube to form discharge plasma and release the metal particles. In a laser oscillation tube that performs laser oscillation by exciting vaporized metal particles with free electrons in discharge plasma, the tips of the anode and the cathode are made of a material with excellent insulation and heat resistance. A metal vapor laser oscillation tube characterized in that only the tip of the electrode is insulated by a ring.