JPH0467797B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a gas laser oscillation device.

[Technical background of the invention and its problems]

A horizontally excited gas laser generates a discharge in a direction perpendicular to the laser oscillation direction, and in devices that operate at relatively high pressures above atmospheric pressure, pre-ionization is required to stabilize the discharge. be. There are various types of this pre-ionization.
One such method is an ultraviolet light preionization method in which a pin electrode is placed parallel to the main electrode. A conventional example using this method will be explained with reference to FIG. That is, the container 1 has a cylindrical airtight structure, and in this container 1, a gas laser medium in which three types of gases, for example, CO ₂ , H ₂ , and He ₂ are mixed at a predetermined ratio, is maintained at approximately atmospheric pressure. It is enclosed. Further, within the container 1, the following elements are arranged in relation to each other. That is, a pair of metal holding plates 2a and 2b are attached to the inner wall of the container 1 in a spaced apart and parallel manner. One retaining plate 2a is combined with a metal mounting plate 3 on the opposite side to the other retaining plate 2b, and an insulator 4 is sandwiched therebetween. The mounting plate 3 is insulated from the container 1 by an insulator 4.
A semi-cylindrical cathode 5 forming one of the main discharge electrodes is provided on the mounting plate 3, and an anode 6, also semi-cylindrical, forming the other main discharge electrode is attached to the holding plate 2b, facing the cathode. Holding plate 2b and mounting plate 3
A large number of pin electrodes 7a and 7b for preliminary discharge are arranged in pairs along the axial direction of the container 1. A first capacitor 8 for preventing unnecessary energy consumption during preliminary discharge is connected to one of the pin electrodes 7a on the cathode 5 side.
Further, a high voltage is applied to the cathode 5 from a grounded high voltage pulse power source 9. Further, the container 1 and the anode 6 are also each grounded.

In the above configuration, the first capacitor 8 is used to adjust the timing of the main discharge and preliminary discharge, and to increase the current peak of the main discharge. ) is desired to be as large as .
However, increasing the capacity of the capacitor also increases its dimensions, resulting in the container 1 becoming larger. On the other hand, even if the first capacitors 8 are made small and arranged in large numbers, there is a limit in the above configuration, and the problem arises that the flow of the gas laser medium flowing into the main discharge region is obstructed.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas laser oscillation device that can suppress preliminary discharge to the necessary minimum and supply maximum energy to the main discharge section.

[Summary of the invention]

In order to achieve the above object, the high voltage side electrode is held by a capacitor without using an insulator.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on drawings showing examples.

FIG. 1 shows an embodiment of the present invention, and parts common to those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.
That is, the difference from the configuration shown in FIG. 4 is that a second capacitor 10, instead of an insulator, is interposed between the holding plate 2a and the mounting plate 3, with both ends connected to the respective plates. and retaining plate 2
A pair of copper lead plates 11a, 11 are connected between a and 2b.
They are connected at point b, and they form a wind tunnel.
Here, an equivalent circuit diagram of the above embodiment is shown in FIG. 2. However, in this circuit diagram, the first and second capacitors 8 and 10 represent the equivalent capacitance when a large number of them are arranged. To explain this circuit, the high-voltage pulse power supply 9 is composed of a high-voltage power supply 9a, a charging resistor 12, and a main discharge capacitor 13, and the circuit is configured so that the charge of the main discharge capacitor flows to the cathode 5 and the anode 6. . here,
A cap switch 14 and inductances 15 and 16 are connected to the line on the anode 6 side from the main discharge capacitor 13 side. Between the inductances 15 and 16, pin electrodes 7a and 7b are connected to the circuit via the first capacitor 8. Further, a second capacitor 10 connected to the above circuit is connected in parallel to the cathode 5 and anode 6 via an inductance 16. The operation of the circuit configured as above will be explained next. High voltage power supply 9a
It is assumed that the main discharge capacitor 13 is sufficiently charged by the above steps and that the gear switch 14 is ignited at an appropriate time. The charge in the main discharge capacitor 13 is transferred to the first and second capacitors 8 and 10 through inductances 15, 16, and 17, respectively. In this case, the transfer rate is determined by the charge amount of the main discharge capacitor and the charge amount of the first and second capacitors 8,
Expressed as a ratio of the amount of charge transferred to 10,
It is well known that the transfer rate is maximum when the parallel capacitance of the first and second capacitors 8 and 10 is equal to the main discharge capacitor. By dividing into 10, it is possible to maximize the transfer rate with relatively simple adjustment. In this case, by making the second capacitor 10 as small in capacity as possible and increasing the first capacitor 8, the maximum transfer rate can be achieved without wasting more energy than necessary for preliminary discharge. be able to.

On the other hand, the line inductance 15, 16, 17
Assuming that the values of are l ₁ , l ₂ , and l ₃ respectively, these values are l ₁ ≫ l ₂ > l ₃ from the above circuit configuration, so after the main discharge starts, the current flowing between the cathode 5 and the anode 6 is As shown in Fig. 4, since it is a combination of i ₁ , i ₂ , and i ₃ , the discharge current is effectively used regardless of the magnitude of the line inductance, and stable discharge is maintained.
With an excimer laser, we were able to obtain nearly twice the output energy of conventional lasers.

〔Effect of the invention〕

As detailed above, by adding the second capacitor and using it as a structure to hold the cathode, which is the high voltage side electrode, it is very easy to increase or decrease the equivalent capacitance inside the container. In this case, an extremely compact structure could be achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is a circuit diagram of the same embodiment, and FIG. 3 is a current waveform diagram.
FIG. 4 is a cross-sectional view showing a conventional example. 1... Container, 5... Cathode, 6... Anode, 7a,
7b... Pin electrode, 8... First capacitor, 9
...Pulse electrode, 10...Second capacitor.

Claims (1)

[Scope of Claims] 1. A gas laser medium, a container enclosing the gas laser medium, a main discharge electrode consisting of a cathode and an anode arranged facing each other at a predetermined distance within the container, and a main discharge region and its vicinity. a first capacitor connected to the preliminary discharge electrode; and a first capacitor connected in parallel to the main discharge electrode and located at a position supporting the back side of the high voltage side electrode of the main discharge electrode. a second capacitor provided;
A gas laser oscillation device comprising: a pulse power source that applies a pulsed voltage to the main discharge electrode. 2. The gas laser oscillation device according to claim 1, wherein the container is made of a cylindrical metal pipe.