JPH05243643A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To provide a gas laser oscillator equipped with a gas circulation system which can ensure a sufficient amount of gas circulation and a sufficient speed of circulation and attain compactization of an apparatus and an improvement in oscillation efficiency. CONSTITUTION:A gas laser oscillator equipped with a gas circulation system with a cooling means consisting of a pair of gas circulation centrifugal fans 21a, 21b fixed face to face in a vicinity of both ends of a fan driving shaft 22, a pair of vortex chambers 26a, 26b so provided as to surround this pair of gas circulation centrifugal fans 2a, 21b and as to make the openings face, and a cylindrical gas cooling heat exchanger 30 where both end openings are joined to the respective openings of this vortex chambers 26a, 26b and arranged concentrically with the driving shaft 22 of the centrifugal fans 21a, 21b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillator provided with a gas circulating system such as an excimer laser oscillator, and more particularly to improvement of a gas circulating system having a cooling means.

[0002]

2. Description of the Related Art FIG. 5 is a vertical sectional view of an excimer laser oscillator as an example of a conventional gas laser oscillator having a gas circulation system.

Reference numerals 11 and 12 are main cathodes and main anodes constituting main electrodes, 13 and 14 are cathode plates and anode plates, 15 is a storage capacitor, 16 is a peaking capacitor, 1
Reference numeral 7 is a preliminary ionization pin, and 18 is a preliminary ionization bulk. Again 2
Reference numeral 0 is a casing, 51 is a cross flow fan for circulating the gas G, 52 is a fan drive shaft, and 53 is a heat exchanger for cooling the gas.

In the conventional excimer laser oscillator described above, a cross flow fan 51 for circulating the gas G between the main cathode 11 and the main anode 12 is installed in the casing 20, and the gas is also used. To cool G,
Heat exchanger 5 consisting of finned tubes in the gas circulation path
3 is interposed.

[0005]

The conventional device constructed as described above has the following problems. Since the cross flow fan 51 has a relatively wide dimension,
This is effective for forming a gas flow with a uniform flow velocity distribution in the width direction. However, the cross flow fan 51 has low efficiency as a gas circulation fan and is difficult to use at high speed. For this reason, it is difficult to obtain a sufficient air flow rate and air velocity, which is a factor that hinders downsizing of the device and improvement of oscillation efficiency.

An object of the present invention is to provide a gas laser oscillating device equipped with a gas circulating system capable of ensuring a sufficient gas circulation amount and a sufficient circulation speed, making the device compact, and improving the oscillation efficiency.

[0007]

In order to solve the above problems and achieve the object, the following measures were taken in the present invention.

That is, in a gas laser oscillating device having a gas circulation system, a pair of gas circulation centrifugal fans fixed so as to face each other in the vicinity of both ends of a fan drive shaft, and the periphery of the pair of gas circulation centrifugal fans, respectively. A pair of vortex chambers that are provided so as to surround and are arranged so that the openings face each other,
A cooling means comprising a cylindrical gas cooling heat exchanger, in which both openings are joined to the openings of the pair of vortex chambers, respectively, and which is arranged concentrically with the drive shaft of the centrifugal fan. It was equipped with a gas circulation system.

[0009]

As a result of taking the above measures, the following effects occur. Since a centrifugal fan is adopted as the gas circulation fan instead of the cross flow fan, the fan efficiency is improved and it can be used at high speed. Further, since the tubular heat exchanger is concentrically arranged on the drive shaft of the centrifugal fan, heat exchange can be performed without interfering with the vortex chamber and drive shaft of the centrifugal fan. For this reason, a sufficient gas circulation amount and gas circulation speed can be secured, and the volume of the circulation system can be reduced, so that the device can be made compact and the oscillation efficiency can be improved.

[0010]

1 is a vertical sectional view showing the structure of an excimer laser oscillator according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line BB of FIG. 3A and 3B are views showing the structure of a heat exchanger for cooling a gas in the first embodiment, FIG. 3A is a schematic perspective view of the whole, and FIG. 3B is a perspective view showing a notched part.

As is well known, the excimer laser oscillator 10 applies a high voltage of several tens of kV between the main electrodes 11 and 12 to generate glow discharge only for several tens of nanoseconds to several hundreds of nanoseconds, and the main electrodes 11 and 12 described above. Excitation of an active medium (rare gas dimer, rare gas oxides, rare gas atoms combined with halogen atoms, etc.) contained in about 1% by volume in the circulating gas G that continuously flows between 12 Then, the excimer state is set, and light having a uniform wavelength generated when returning from this state to the state before the excitation is resonated between the mirrors and extracted as laser light. The specific structure will be described below.

In FIG. 1, 11 and 12 are a main cathode and a main anode which constitute a main electrode, and they are attached to a cathode plate 13 and an anode plate 14 so as to face each other. Reference numeral 15 is a storage capacitor, 16 is a peaking capacitor, 17 is a preionization pin, and 18 is a preionization bulk.

As shown in FIG. 2, a pair of gas circulation centrifugal fans 21a, which are the main components of the gas circulation system, are provided in the hollow portion of the casing 20 supporting the above electrode portion.
The fan drive shaft 22 is fixed at 21b so as to face both ends thereof. That is, a pair of gas circulation centrifugal fans 21
The keys a and 21b are fixed to the outer circumference of the fan drive shaft 22 by keys 23a and 23b in a non-rotating state. 24a, 2
4b is a bearing for the fan drive shaft, and 25a and 25b are support plates that support the bearing. A pair of vortex chambers 26a and 26b are provided so as to surround the pair of gas circulation centrifugal fans 21a and 21b, respectively. The pair of vortex chambers 26a and 26b are arranged such that their openings face each other. 30 is a heat exchanger for gas cooling. The gas cooling heat exchanger 30 has openings at both ends thereof, that is, a water supply header 32 a and a drain header 32 which will be described later.
The end surface of b is joined to the openings of the pair of vortex chambers 26a and 26b, respectively, and is arranged concentrically with the drive shaft 22 of the centrifugal fans 21a and 21b.

As schematically shown in FIGS. 3A and 3B, the gas cooling heat exchanger 30 includes a water supply header 32a having a water supply port 31a and a drainage header 32b having a drainage port 31b. It is attached to both ends of the heat exchanger body 33. As shown in FIG. 3B, the heat exchanger main body 33 is formed by spirally forming a cooling water pipe 35 made of aluminum having a plurality of cooling water passages 34, and is formed by forming the spiral shape. A wavy cooling fin 36 is interposed between the water pipes 35, and the whole is formed in a cylindrical shape.

The gas laser device 10 having the above structure operates as follows. In order to generate a glow discharge between the main cathode 11 and the main anode 12, first the storage capacitor 1
The peaking capacitor 16 is stored in the capacitor 5 by circuit operation.
Move to. At this time, the electric charge is transmitted from the preionization pin 17 to the preionization chamber 18 while generating an arc discharge. At this time, the circulating gas G (for example, XeCl) flowing between the main cathode 11 and the main anode 12 receives the ultraviolet rays generated by the arc discharge, and is preliminarily ionized. The electric charge that has moved to the peaking capacitor 16 following such a course flows between the main cathode 11 and the main anode 12 after the voltage between the main electrodes reaches the break voltage, and causes glow discharge. This glow discharge is generated at a number of repetitions of several times / [seconds] to hundreds of times / [seconds] by repeatedly charging and discharging the storage capacitor 15 and the peaking capacitor 16.

During the glow discharge, the centrifugal fans 21a and 21b are operated and the cylindrical heat exchanger 3 is operated.
With the operation of 0, the cooled circulating gas G circulates in the gas circulation system as indicated by the arrow in FIG. Therefore, fresh active substance is always supplied between the main cathode 11 and the main anode 12.

When the apparatus having the above structure was actually operated and the performance was confirmed, an output of 300 Hz, 150 W was obtained. At this time, the rotation speed of the centrifugal fans 21a and 21b is 8000 rpm, and the gas blow rate is 20 liters /
[Second], the required cooling heat quantity was 2500 kcal / [hour], but the gas temperature was maintained at 40 ° C or lower. The water flow rate was 20 liters / [sec]. FIGS. 4A and 4B are perspective views showing the configurations of the cylindrical heat exchangers of the gas laser oscillators according to the second and third embodiments of the present invention, respectively.

A cylindrical heat exchanger 40 shown in FIG. 4 (a).
The water supply header 42a having the water supply port 41a and the drainage header 42b having the drainage port 41b are attached to both ends of the heat exchanger body. As shown in the figure, the heat exchanger main body has a plurality of flat cooling water pipes 43 whose both ends are joined to the headers 42a and 42b linearly extending in the axial direction of the cylinder so that the cooling water pipes 43 are connected to each other. The cooling fins 44 are interposed in the entire structure to form a hexagonal cylinder.

A cylindrical heat exchanger 45 shown in FIG. 4 (b).
The water supply header 46a having the water supply port 41a and the drainage header 46b having the water discharge port 41b are attached to both ends of the heat exchanger body. The heat exchanger body has one end joined to the water supply header 46a as shown in the figure,
Prepare two single flat cooling water pipes 47 having the other end joined to the drain header 46b, and extend these linearly along the axial direction of the cylinder and meander along the circumferential direction. Then, the cooling fins 48 are interposed between the cooling water pipes 47 to form a two-layer tubular main body as a whole.

It was confirmed that even when the cylindrical heat exchangers 40 and 45 having the constructions shown in FIGS. 4A and 4B were used, the same effects as those of the first embodiment were obtained. The present invention is not limited to the above embodiment. For example, in the above-mentioned embodiment, the example in which the present invention is applied to the excimer laser oscillating device is shown, but it can be widely applied to a carbon dioxide gas laser oscillating device and the like. Of course, various modifications can be made without departing from the scope of the present invention.

[0021]

According to the present invention, the centrifugal fan is adopted as the gas circulation fan instead of the cross flow fan, so that the fan efficiency is improved and it can be used at high speed. Further, since the tubular heat exchanger is concentrically arranged on the drive shaft of the centrifugal fan, heat exchange can be performed without interfering with the vortex chamber and drive shaft of the centrifugal fan. Therefore, a sufficient gas circulation amount and gas circulation speed can be secured, and
The volume of the gas circulation system can be reduced. Therefore, the device can be made compact and the oscillation efficiency can be improved.

Thus, according to the present invention, it is possible to provide a gas laser oscillator having a gas circulation system which can secure a sufficient gas circulation amount and gas circulation speed, can be made compact, and can be improved in oscillation efficiency.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the configuration of an excimer laser oscillator according to a first embodiment of the invention.

FIG. 2 is a sectional view taken along the line BB of FIG.

FIG. 3 is a diagram showing a structure of a gas cooling heat exchanger in the first embodiment, FIG. 3 (a) is a perspective view showing an outline of the whole, and FIG.
FIG. 3 is a perspective view showing a notched part.

FIG. 4 is a view showing the structure of a gas cooling heat exchanger in an excimer laser oscillator according to another embodiment of the present invention,
(A) is a perspective view which shows the outline of the heat exchanger which concerns on 2nd Example, (b) is a perspective view which shows the outline of the heat exchanger which concerns on 3rd Example.

FIG. 5 is a vertical sectional view showing a configuration of an excimer laser oscillator according to a conventional example.

[Description of Reference Signs] 10 ... Excimer laser oscillator, 11 and 12 ... Main cathode and main anode constituting main electrodes, 13 and 14 ... Cathode plate and anode plate, 15 ... Storage capacitor, 16
… Peaking condenser, 17… Preionization pin, 18…
Pre-ionization bulk, 20 ... Casing, 21a and 21b
... a pair of centrifugal fans for gas circulation, 22 ... a fan drive shaft,
23a and 23b ... Keys, 24a and 24b ... Fan drive shaft bearings, 25a and 25b ... Bearing support plates, 26a and 26b ... A pair of vortex chambers, 30 ... Gas cooling heat exchanger, 31a ... Water inlet, 31b ... Drainage Mouth, 32a
... water supply header, 32b ... drainage header, 33 ... heat exchanger body, 34 ... cooling water channel, 35 ... aluminum cooling water pipe, 36 ... cooling fin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location 7454-4M H01S 3/097 Z (72) Inventor Toshiaki Katsura 4-6 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture No. 22 Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Masanori Masumoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Institute (72) Inventor Shinji Sese Hiroshima City, Hiroshima Prefecture 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd.

Claims (1)

[Claims] 1. A gas laser oscillator including a gas circulation system, wherein a pair of gas circulation centrifugal fans fixed so as to face each other in the vicinity of both ends of a fan drive shaft, and a periphery of the pair of gas circulation centrifugal fans. A pair of vortex chambers provided so as to surround each other and arranged so that the openings face each other, and both end openings are joined to each opening of the pair of vortex chambers, and the drive shaft of the centrifugal fan A gas laser oscillating device comprising: a cylindrical heat exchanger for cooling a gas, which is arranged concentrically with the above, and a gas circulation system having a cooling means.