JPS61180488A - Ion laser tube - Google Patents

Abstract

PURPOSE:To produce a stable output for a long term, by providing with metal rings so that they are positioned on both sides of respective disks of a silicon carbide disk group constituting the fine laser tube. CONSTITUTION:In an alumina ceramic housing 12, metal rings 13, a tungsten anode 15 and silicon carbide disks 14 are arrayed alternately to constitute a fine tube section 11. Optical windows 2, 2' are mounted on both ends of the housing 12, and a cathode 7 being provided in the housing 12. Heat resulting from discharge between the anode 15 and cathode 7, is conducted to cooling water through the disk group 14 and housing 12 from the laser fine tube section 11. Since the metal rings 13 position precisely the disk group 14 while the heat fed from the disk group 14 is conducted to the housing 12, a stable output can be produced for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ion laser tube having a capillary metal made of silicon carbide.

(Prior art and its problems) Conventionally, in the ion laser tube for this purpose, as shown in FIG. By providing an optical resonator equipped with a set of laser beams, laser oscillation is performed and laser light is output.

Ion lasers perform laser oscillation by transitioning between the energy levels of ionized rare gases, and are the only gas lasers that can achieve high output continuous oscillation in the visible range of the order of Watts, so they can be used for Raman spectroscopy, holography, etc. widely used. However, since the ionization energy of the rare gas is high, it is necessary to cause a large current arc discharge of several tens of amperes within the laser tube.

For this reason, a group of graphite disks 4.5.6i arranged with a hole in the center is used to form a laser thin tube with a row of holes in the center. Furthermore, in order to release the heat of 6 to 9 kW to the outside of the laser thin tube, cooling water is passed through the outside of the tube for cooling. However, the heat generated in the laser thin tube section 11 of the graphite disk group 4.5.6 heats up and becomes red hot (900 to 1300 degrees CB) due to conduction of heat from the graphite disk sections 4, 5.6'i. The radiant heat from the heat radiation surface 10 of the graphite disk group can be directly released to the outside, but the area S of the heat radiation surface 10 is (
1) It is expressed by the formula.

8=t-d・π (1) t: Thickness of graphite disk d: Diameter of graphite disk π: Circumference For example, thickness of graphite disk t=5 order, diameter d-” When the distance is 30 m, the area 5 of the heat radiation surface 10 is 471-, so the temperature of the laser tube section 11 increases and the temperature increases to 2000 m.
It even reaches ℃B. Therefore, if it is used for a long time, the graphite in the laser tube part 11 will turn into powder and crumble.
The diameter of the hole in the laser tube section 11 gradually increases along the discharge shape, and the graphite powder flows into the graphite disk group 4.
．． 5.6 and deteriorates the insulation resistance between the anode 3 and cathode 7. This adversely affects the start of discharge between the anode 3 and cathode 7, making it difficult to discharge. Furthermore, as the diameter of the hole in the laser thin tube section 11 increases, the current density of arc discharge decreases, causing problems such as a decrease in laser output and an inability to maintain the laser oscillation mode in T E Mo o mode. In addition, when the graphite disk group 4.5.6e is high-frequency heated to release gas in the exhaust process, the laser tube 1 and the heat radiation surface 10 are in full contact with each other, so the outside air is passed through the laser tube 1tl. Even if a quartz tube is used as the laser tube 1, the temperature of the laser thin tube portion 11 of the graphite disk group 4.5.6 is limited to about 900 to 13000 B because heat is conducted to the laser tube 1.

For this reason, when the temperature of the laser tube section 11 reaches 2000° C.B, the impurity gas stored in the graphite disk group 4.5.6 is released, resulting in a decrease in laser output and generation of graphite powder at the anode 3. There is a problem of insulation deterioration between the cathodes 1.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ion laser tube that eliminates the above-mentioned drawbacks and can easily start discharging and obtain stable output over a long period of time.

(Another Means to Solve the Problem) The present invention provides a laser capillary tube consisting of a group of silicon carbide disks having a hole for a capillary tube in the center between an anode and a cathode disposed in a vacuum envelope. The laser tube is characterized in that metal rings are provided on both sides of each disk constituting the group of silicon carbide disks, and the vacuum envelope and the metal rings are fixed to each other by brazing. Preferably, the envelope is made of alumina ceramic, and the anode is made of tungsten.

(Example) Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, in which a metal ring 13 is placed inside an alumina ceramic envelope 12. Tungsten anodes 15 and silicon carbide disks 14i are alternately arranged as shown in the figure to form a thin tube section. Note that 2.2' is an optical window, 7 is a cathode, and 16 is an anode introduction rod. A laser tube having such a configuration is manufactured as follows. Alumina ceramic envelope 1
2 to several hundred degrees Celsius, and a metal ring 13. Tungsten anode 15. Metal ring 13. Brazing filler metal, silicon carbide disk 14. Metal ring 13゜brazing metal I
NK anode and silicon carbide disk group 14t
- built-in cathode 7 of alumina ceramic envelope 12;
The alumina ceramic envelope 12 and the metal ring 13 are brazed to each other by the brazing material by placing them in a brazing furnace at 900° C. to 1000° C. with their sides facing up and reheating them.

In addition, an alumina ceramic envelope 12 and a metal ring 13
has a large coefficient of thermal expansion of 4.6 to 5.6X10/℃, and silicon carbide disk group 14 has a coefficient of thermal expansion of 4.2X10/℃.
'C, so the inner diameter of the alumina ceramic envelope 12 and the outer diameter of the silicon carbide disk group 14 are made the same, and the alumina ceramic envelope 12 is made the same as described above.
The silicon carbide disk group 14t can be assembled in a state where it is heated to 100° C. and its inner diameter is enlarged.

When cooled, the alumina ceramic envelope 12, which had expanded until now, contracts and comes into close contact with the silicon carbide disk group 14. Therefore, heat due to the discharge between the anode 15 and the cathode 7 is transferred from the laser tube section 11 to the silicon carbide disk group 14. Alumina ceramic envelope 12
1 and is conducted to cooling water (not shown) flowing outside the alumina ceramic envelope 12. Similarly, the coefficient of thermal expansion of the tungsten anode is 4.0X10/'
Since the anode 15 has a small C and is brought into close contact with the inner diameter of the alumina ceramic envelope 12, the heat generated by the anode 15 is conducted through the entire alumina ceramic envelope 12 to the cooling water flowing outside the alumina ceramic envelope 12. Ru. The metal ring 13 also positions the anode 15 and the silicon carbide disk group 14 and allows cooling water to flow outside the alumina ceramic envelope 12 through the hot metal alumina ceramic envelope 12 of the anode 15 and the silicon carbide disk group 14. It acts as a heat conductor.

(Effects of the Invention) According to the present invention, the heat in the laser thin tube portion 11 is suppressed by thermal conduction, so that the temperature rise is extremely low, on the order of several hundred degrees Celsius. Therefore, even after long-term use, the tungsten anode 15. The silicon carbide disk group 14 does not deteriorate. Therefore, the diameter of the hole in the laser thin tube portion 11 does not change, and sputtering of the silicon carbide disk group does not occur. For this reason, it is possible to obtain an ion laser tube that allows easy discharge initiation and stable laser output over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention, Fig. 2 is a sectional view showing an embodiment of the present invention.
2 is a cross-sectional view showing a conventional ion laser tube, and FIG. 2 is an axial cross-sectional view of a graphite component portion of a conventional ion laser tube.
・Optical window, 3... Anode, 4, 5.6...
...graphite disk group, 7... cathode, 8, 9... gas return bus, 10...
... Heat radiation surface, 11 ... Laser thin tube part, 12
...Alumina ceramic envelope, 13...
... Metal ring, 14 ... Silicon carbide disk group, 15 ... Tungsten anode.

Claims (1)

[Claims] In an ion laser tube having a laser tube consisting of a group of silicon carbide disks between an anode and a cathode in a vacuum envelope, each disk constituting the group of silicon carbide disks has a metal ring on both sides, and is made of alumina ceramics. An ion laser tube characterized in that an envelope and the metal ring are brazed.