JPH0391977A - Pulse generator - Google Patents

Abstract

PURPOSE:To enable pre-ionization and primary discharge to be smoothly carried out by a method wherein the diameter of a part of a pre-discharge electrode opposed to a primary electrode is so set as to make the electric field of the part concerned lower than the discharge electric field of gas laser medium in intensity, and the diameter of the tip of the pre-discharge electrode is made smaller than that of its part opposed to the primary electrode. CONSTITUTION:The diameter of a part of a pre-discharge electrode 6 opposed to primary electrodes 2 and 3 is made large enough so as to make the electric field of the part concerned lower than the discharge electric field of mixed gas 1 in intensity. The diameter of the tip of the pre-discharge electrode 6 is made much smaller than that of its part opposed to the primary electrode. That is, the part of the pre- discharge electrode 6 opposed to the primary electrodes 2 and 3 are formed large in diameter, whereby an electric field 10 of the opposed part becomes low in intensity and consequently voltage withstanding strength between the pre-discharge electrode 6 and the primary electrode 3 is sharply improved. On the contrary, the opposed parts of the pre-discharge electrodes 6 or the tips of the electrodes 6 are formed small in diameter, so that discharge starts easily between the pre-discharge electrodes 6. By this setup, pre-ionization and primary discharge following it are smoothly and stably carried out.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a pulse generator used in a high repetition rate pulsed laser oscillation device, and particularly relates to an insulation structure of a discharge gap portion thereof. It is related to.

(Prior art) In recent years, with the technological development of various high repetition pulse laser oscillation devices such as CO2 lasers, excimer lasers, and copper vapor lasers, from the viewpoint of practical application and generalization, laser oscillation devices are becoming more compact and have higher performance. ization is required.

FIG. 3 shows an example of a pulse generator for such a high repetition pulse laser oscillation device. Although not shown, this pulse generator is housed in an airtight container. A mixed gas (laser medium) 1 such as CO2, H2, He, etc. is sealed in this airtight container, and in the atmosphere of this mixed gas 1, a pair of main electrodes 2.3 on a high pressure side and a low pressure side are connected. They are placed facing each other at a constant distance. The main electrodes 2 and 3 are fixed to support plates 4 and 5 provided on their back surfaces, respectively, and each support plate 4 and 5 is fixed to a container (not shown). Preliminary discharge electrodes 6 are arranged on both sides of the main electrodes 2 and 3 (main discharge space), and insulating supports 7a
．． It is supported and fixed at 7b. Further, a large number of peaking capacitors 8a, 8b are arranged on both sides of the main electrode 2.3, one end of the peaking capacitors 8a, 8b is connected to the preliminary discharge electrode 6, and the other end is connected to the support plate 4. .5
It is connected to the. Furthermore, wind tunnels (not shown) are provided on both sides between the main electrodes 2 and 3, and a mixed gas 1 is fed between the main electrodes 2 and 3 from the wind tunnel on one side, and this mixed gas 1 is transferred to the wind tunnel on the opposite side. A series of circulation system is formed in which the mixed gas 1 is returned to a cooler (not shown) and sent again between the main electrodes 2 and 3. Note that 9 in the figure is a high voltage line connecting between the main electrode 2 on the high voltage side and an external power source (not shown).

When a high voltage is applied from an external power source (not shown) to the pulse generator shown in FIG.
At the same time, as the voltage of the beaking capacitors 8a and 8b increases, the voltage between the main electrodes 2 and 3 also increases, and this voltage increases the gap length between the main electrodes 2 and 3.
When a constant current injection determined depending on the pressure of the mixed gas 1 in the container is reached, the charges stored in the peaking capacitors 8a and 8b are injected into the main electrodes 2 and 3, generating a glow discharge. This glow discharge excites the mixed gas 1, causing laser oscillation, and a resonator (not shown) causes
Laser light is extracted to the outside.

(Problem to be Solved by the Invention) By the way, in the pulse generator of the high repetition pulse laser oscillation device as described below, a potential difference occurs in the insulating section 10 between the preliminary discharge electrode 6 and the main electrodes 2 and 3. . In this case, taking the low voltage side in FIG. 3 as an example, there is a voltage between the preliminary discharge electrode 6 and the main electrode 3 that is approximately 1/2 of the discharge voltage between the main electrodes 2 and 3.
A potential difference of . This potential difference corresponds to the potential difference of one peaking capacitor 8a. In this way, when a potential difference is generated between the preliminary discharge electrode 6 and the main electrode 3, an electric field is generated, for example, in the direction shown by the arrow 11 in the figure.

This electric field 11 increases if the configurations of both the preliminary discharge electrode 6 and the main electrode 3 are unequal, and decreases if the configurations of both the preliminary discharge electrode 6 and the main electrode 3 are equal. Further, when this electric field 11 exceeds the discharge electric field of the mixed gas 1, a discharge occurs between the preliminary discharge electrode 6 and the main electrode 3.

When this portion discharges, no discharge occurs between the main electrodes 2 and 3, and the device no longer functions as a pulse generator. As shown in this example, many haze devices have conventionally become incapable of functioning as pulse generators due to defects in the shape of the pre-discharge electrode. The main reason for this is thought to be that the electric field between the preliminary discharge electrode 6 and the main electrodes 2 and 3 becomes higher as a result of making the preliminary discharge electrode 6 thinner in order to make it easier for the preliminary discharge electrodes 6 to discharge each other. It will be done.

The present invention was proposed in order to solve the problems of the prior art as described above, and its purpose is to easily enable discharge between the pre-discharge electrodes and to improve the insulation between the pre-discharge electrode and the main electrode. To provide an excellent pulse generator that can perform preliminary ionization and main discharge smoothly, reliably obtain stable main discharge, and generate stable pulses by improving proof strength. .

[Composition of four generators] (Means for solving the problem) The pulse generator according to the present invention has a diameter of the portion of the pre-discharge electrode facing the main electrode such that the electric field of this portion is lower than the discharge electric field of the gas laser medium. It is characterized in that the diameter of the tip of the preliminary discharge electrode is smaller than the diameter of the portion facing the main electrode.

(Sakugawa) In the present invention having the configuration as described above, the electric field between the preliminary discharge electrode and the main electrode is made lower than the discharge electric field. Since the diameter of the tip of the pre-discharge electrode is narrow, discharge can easily occur between the pre-discharge electrodes.

Therefore, good pre-ionization and stable main discharge can be ensured.

(Example) Below, an example of a pulse generator using the main beating will be described as a first example.
This will be explained in detail with reference to the drawings and FIG. Note that the same parts as those in the prior art shown in FIG. 3 are given the same reference numerals.
The explanation will be omitted.

As shown in FIG. 1, in this embodiment, the diameter of the portion of the preliminary discharge electrode 6 facing the main electrodes 2 and 3 is set so that the electric field in this portion is lower than the discharge electric field of the mixed gas 1. It is being structured. Furthermore, the diameter of the tip of the preliminary discharge electrode 6 is much smaller than the diameter of the portion facing the main electrode.

Note that the configuration of other parts is similar to the prior art shown in FIG.

The operation of this embodiment thus structured is as follows. That is, by forming the part of the pre-discharge electrode 6 that faces the main electrodes 2 and 3 thick, the electric field 11 in this part becomes low, as shown in FIG. The withstand voltage is significantly improved. In other words, the insulation strength of the insulating portion 10 is increased, and the insulation is stable. On the other hand, since the diameter of the tip portions of the preliminary discharge electrodes 6 that are opposed to each other is made much smaller, discharge easily occurs between the preliminary discharge electrodes 6. Although FIG. 2 shows the configuration of only the low pressure side, the high pressure side is also configured in the same manner and has the same effect.

As shown in 12 above, in this example, the insulation is strengthened at the insulation weak point between the preliminary discharge electrode and the main electrode, which had been a problem in the past, while it is now possible to easily discharge between the preliminary discharge electrodes. Therefore, preliminary ionization and subsequent main discharge can be performed smoothly and stably.

Note that the present invention is not limited to the above embodiments,
For example, the specific diameter of the pre-discharge electrode can be selected as appropriate depending on the case, and the ratio between the diameter of the portion of the pre-discharge electrode that faces the main electrode and the diameter of the tip can also be selected as appropriate. be. Further, the shape of the portion of the main electrode that faces the preliminary electrode is not particularly limited.

[Initial effect] As described above, in the present invention, by simply improving the shape of the pre-discharge electrode, the dielectric strength between the pre-discharge electrode and the main electrode can be significantly improved, and at the same time, the discharge between the pre-discharge electrodes can be improved. Therefore, it is possible to provide an excellent pulse generator that can perform preliminary ionization and main discharge smoothly, reliably obtain a stable main discharge, and generate stable pulses.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of a pulse generator according to the present invention, FIG. 2 is a front view showing an electric field between a preliminary discharge electrode and a main discharge in the same embodiment, and FIG. 3 is a front view showing an electric field between a preliminary discharge electrode and a main discharge in the same embodiment. It is a front view showing an example of a generator. 1... Mixed gas, 2, 3... Main electrode, 4, 5...
Support plate, 6... Pre-discharge electrode, 7a, 7b... Insulating support, 8a, 8b... Peaking capacitor, 9.
...High voltage line, 10...Insulation part, 11...Electric field.

Claims (1)

[Claims] Main electrodes on the high-voltage side and the low-voltage side arranged oppositely in the gas laser medium atmosphere, a preliminary discharge electrode arranged near the space between the main electrodes, and a pre-discharge electrode arranged on the side of the main electrodes. In a high-repetition type pulse generator that generates a pulse output by repeatedly discharging the charge stored in the capacitor between a main electrode through the pre-discharge electrode, the diameter of the portion of the pre-discharge electrode that faces the main electrode. is set so that the electric field in this part is lower than the discharge electric field of the gas laser medium, and the diameter of the tip of the preliminary discharge electrode is smaller than the diameter of the part facing the main electrode. Pulse generator.