JPH02161787A - Carbon dioxide gas laser device - Google Patents

Abstract

PURPOSE: To stabilize a laser by coating the wall facing a laser amplifier space with Au, for regenerating CO2 resolved by catalytic action of Au against a mixed gas. CONSTITUTION: With the outside periphery of an inside tube 23A surrounded with an outside tube 24, a cooling fluid is made to flow in tubes 23A-24. Then, the space formed with tubes 23A, 25, and 26 and mirrors 27 and 28 is filled with such laser gas mixture as O2 , N2 and He, for sealing up. Relating to the laser, on the inside periphery of the tube 23A facing an amplification space, rings 30K, 30L, 30M, etc., of Ni plated with Au, etc., area provided, or, a coat 30A of fine powder of Au is formed. With this, the Au affects a catalytic action on generation on CO2 generation at n ambient temperature, its speed matching CO2 resolution speed in laser. Thus, CO2 is regenerated, with the laser stabilized.

Description

[Detailed description of the invention] (Background of the invention) The background of the present invention will be explained in two parts.

(Technical field of invention) The present invention relates to both catalysts and lasers.

In particular, the present invention relates to an apparatus and method for improving carbon dioxide lasers by catalytically reproducing carbon dioxide gas decomposed by electrical discharge.

(Description of the Prior Art) Since the invention of carbon dioxide lasers, an undesirable feature of these lasers has been that the electrical discharge required to excite the laser gas decomposes carbon dioxide during the discharge in one of two ways: There was a fact that it would happen.

CO2+ e 4 Co + 0-CO2+
e −+ Co + O+ e where e is the electron during discharge.

This reaction ultimately reaches an equilibrium state as shown by the following reaction formula.

CO + yOz ヰ Cot Normally, more than 60% of carbon dioxide gas does not decompose, and the 6 problems in which an equilibrium state is reached at less than 60% are C
O and O2 have some negative effects on the laser, resulting in output loss, gain loss, and discharge instability characteristics.

With a relatively high-power laser, gas (a mixed gas of CO2, N2, and He, which accounts for about 80% of the total) is continuously flowed during the discharge for a short period of time to decompose some of the CO2 in the solder. Therefore, these negative effects are eliminated.

The rate of decomposition is determined by many factors such as current density and gas pressure, but - for boat fishing, this rate of decomposition is very fast and usually
It is between 0.01 seconds and 10 seconds.

This decomposition reaction was first identified and characterized by the applicant in 1967. Since then, much work has been done on high power carbon dioxide lasers in a pilot process to minimize the cost and harm of gas consumption. Relatively low output (
(60 watts or less), sealed-off type carbon dioxide lasers have been manufactured and used; however, in that case, CO2 is emitted during discharge.
The power loss associated with partial decomposition was acceptable.

When gas is passed through a carbon dioxide laser and the used gas is dumped into the outside air, most of the mixed gas is helium, so the carbon dioxide laser consumes a substantial amount of helium. For example, a 1,000 watt carbon dioxide laser requires two gases to be circulated to produce one output under standard pressure and temperature.
Approximately 100 liters of laser gas (mostly helium) is consumed per hour. Fortunately, CO and 02 are approximately 330°C
It is known that CO2 can be reconverted using a platinum catalyst heated to . To do this, a vacuum pump is used to constantly circulate the gas through a closed circuit that includes the discharge section of the laser, a heated catalyst, and a vacuum pump; unfortunately, this method is expensive and complex. However, it still wastes gas and approximately lθ% of the gas is discarded each cycle and must be replenished with new gas.
Currently, a 1°OO watt carbon dioxide laser with a platinum regenerator typically consumes about lθ liters of laser gas per hour.

This problem must be considered from a broader perspective, considering that 10,000 lasers are currently being sold around the world.

Although sealed versions that do not consume helium are used, the majority of lasers are of a type that wastes enormous amounts of helium, a natural resource that is not only expensive but also in limited supply. It is something that consumes. Although sealed-off carbon dioxide lasers do not consume helium, they typically have a disadvantage in that their output is significantly lower than that of gas-flow lasers of the same size.

This issue has received a great deal of attention. Prior art references and patents in this regard include:

1. P. D. Tannen et al. “Chemical composition of carbon dioxide lasers” IEEE Journal
l of Quantum EIectroni
c+Vol QEIO, No 11974; 2, C, W
“Catalytic Control of Gas Chemistry in Sealed TEA Carbon Dioxide Lasers,” J. Appl. Phys., 50(4) April, 197.
9;3, D, S, 5tark [100Hz sealed TEA carbon dioxide laser using high-intensity carbon dioxide gas and catalyst at room temperature] J, Ph7g, E
:Sci, In5tru+s, 18.1983
158-181; 4, U.S. Patent Division 3,789,320
No. W, D, Hepburn “Circulation System for Gas Lasers” 5, U.S. Patent Department 3,
No. 569,857 J, A, MaCken "Methods and means for achieving chemical equilibrium in sealed-off carbon dioxide lasers" 6, A, B,
"Removal of Carbon Monoxide from Air" by Lamb et al., J. of Industrial and En.
g, Cbes, Mar, 1920° In addition to using an external catalyst, it is possible to use a heated platinum wire inside the laser or a heated cathode that exhibits catalytic activity.
Attempts have also been made to install a catalyst inside the laser.

However, this has not been successful in reversing the carbon dioxide decomposition reaction because the gas diffusion is too slow and it reaches the narrow area of the tube containing the heated platinum wire and the heated cathode. Because you can't.

It is not possible to cover large areas of the laser discharge space with heated platinum. If they did so, they would be able to successfully resynthesize the decomposed gas.

A large area of heated platinum would raise the gas to a temperature unsuitable for laser operation, thus shutting down the carbon dioxide laser.

Catalysts that act on the CO-02 reaction at ambient temperature are much slower than heated platinum; these catalysts that act at ambient temperature include tin oxide coated with platinum (Ref. (3)). , hobcalide (References (6)
Mn0z50%.

Au030%, Co20315% and Agz05%),
and cobalt oxide (Ref. (6)).To use these catalysts that operate at ambient temperature, it is necessary to compensate for the slow reaction sphericity by bringing the gas into close contact with the catalyst. is necessary.

This is usually done by passing a gas through a granular catalyst.

To do so, it is necessary to mount the catalyst away from the laser amplification space. A pump is used to circulate the gas through the catalyst; experiments have shown that the above-mentioned catalysts operating at ambient temperature have a slow reaction sphericity, destabilize the discharge, and cause chemical decomposition of the catalyst. It has been found that it cannot be used on the wall of the discharge space inside the laser for various reasons such as - Contrary to the conventional technology, the present invention regenerates the decomposed carbon dioxide inside the discharge space of the carbon dioxide laser. teaches how to synthesize. Recombining within the discharge space allows two discharges to be made at ambient temperature without making them unstable and without necessarily having to recirculate the gas.

The present invention can also be used to resynthesize carbon dioxide gas decomposed in a gas flow laser. In that case, due to the low operating temperature, there is no need to heat the gas as would be required with platinum catalysts. The method of the present invention, which has various other effects, can also be applied to devices other than lasers.

(Summary of the Invention) Carbon dioxide lasers have the disadvantage that carbon dioxide gas is decomposed into carbon monoxide and oxygen by electric discharge. However, the discharge also short-lives the energetic and highly reactive form of oxygen. The present invention discloses a catalyst that operates only in the presence of such short-lived and energetic oxygen. .

In one embodiment of the invention, at zero ambient temperature coating the wall facing the laser amplification space with finely powdered gold, carbon oxides and energetic oxygen (i.e. atomic oxygen) are deposited on this entire surface. React quickly.

In diffusion-limited lasers, this gold catalyst is widely distributed on the wall facing the discharge. The gold is powdered sufficiently finely so that the discharge does not deviate.

In another embodiment applied to a convective gas type laser.

A gold catalyst is placed in the gas stream near the discharge end of the laser discharge. In addition to lasers, the invention is applicable to other devices that produce high-energy oxygen.

(Description of Examples) The CO-02 reaction is an exothermic reaction, but since it requires a large amount of activation energy to start, a non-catalytic material such as aluminum oxide, which does not proceed at ambient temperature, is
To proceed with this reaction, to
Even at too many degrees Celsius, only a small fraction of the thermally excited molecules
By obtaining high energy that exceeds this activation energy, CO
This is a type of thermal chemical reaction because the activation energy is exceeded by the kinetic energy of the molecules. The activation energy for oxidizing CO with O2 is considered to be 1.5 electron volts or more.

Even when using catalysts such as platinum, palladium, cobalt oxide or fobucalide, temperature (kinetic energy of the molecules) determines whether this activation energy is exceeded. Catalysts merely reduce this activation energy through intermediate reactions. However, Applicant believes that the unique environmental conditions that make the new approach to catalysts usable are
It was discovered that it is inside a carbon gas laser.

Inside the carbon gas laser, oxygen with a high energy level is created by electrical discharge. This high-energy oxygen cannot normally combine with CO (without a third structure) due to its excess energy; it is not a matter of how the activation energy is exceeded; in the gas phase, CO2
The question is how to remove energy without the molecules decomposing.6 For example, in the very process of decomposing CO2, atomic oxygen (O) is produced according to the following reaction equation.

CO2+ e →Co + 0 + e Atomic oxygen is also produced within the discharge in several ways, including the following reaction equation.

02 + e → 0+0 Atomic oxygen often diffuses as it is to the walls.

Some atomic oxygens combine with 02 to form ozone 03, but this binding reaction requires a third structure. This ozone is also very reactive.

Finally, diatomic oxygen (02) is known to have at least two long-lived excited vibrational states, shown next as the 02 tree and the 02 tree.

For this reason, even oxygen molecules (02) are continuously excited and maintain a high-energy state as long as they exist during the discharge.Therefore, during the discharge, high-energy oxygen has an electrically neutral form. There are at least four. In all of its forms, once the gas leaves the discharge region for a time longer than the lifetime of the various high-energy oxygen species, the high energy content of these four electrically neutral oxygen species, which are not normally present in the air or in the laser gas, The energy states and the energy at which their oxygen is formed are:

1) Atomic oxygen 0; 2.13eV (endothermic 25
0 to J#+ol) 2) Osi 7 0:x; 1.5eV
(Endothermic 140 to J#+ol) 3) Excited oxygen 02 zero;
1 eV (endothermic 92 KJ/mol) 4) Excited oxygen 02K0; 1.13 eV (endothermic 154 KJ/m
ol) In addition to the four electrically neutral forms of high-energy oxygen mentioned above, there are various sources of ionized high-energy oxygen that have been identified during carbon dioxide laser discharge. The main positive ions that can contribute as a source of oxygen are 02.0 and N O+.

Some of the positive ions are attracted to the walls of the discharge space.

Neutralizes electrons that diffuse into the wall. Ultimately, there is a possibility that the ultraviolet light generated during the discharge is absorbed by a certain solid, generating hot electrons, and the hot electrons decompose 02 into atomic oxygen on the solid surface.

(“Thermal oxidation of silicon by ultraviolet excitation JE, ll
I.

Young, Appl, Ph7. Among the high-energy forms of oxygen mentioned above, atomic oxygen is the most important because it is large in amount and reacts quickly.

These electrically neutral and ionized substances are
In low-velocity gas flow type carbon dioxide lasers, which have low gas pressure and a small discharge space, all except ozone lose their activity when they collide with a wall, and their half-life is less than 1d20 milliseconds.

However, in the case of gas flow lasers with high gas pressure and a large discharge space, the amount of electrically neutral, high-energy oxygen that diffuses to the walls is very small and lasts perhaps <1/10th of a second or more. may be possible.

The goal should therefore be to harness the energy of these short-lived, high-energy oxygen (and possibly UV) sources to obtain at least some of the energy needed to initiate the catalytic reaction from the electrical discharge. be. This allows the thermal energy requirements to be sufficiently low that the catalytic reaction can proceed rapidly even at temperatures below about 50°C.

While doing this, it was discovered that there are two classes of substances that catalyze the production of CO2 in lasers. These materials are oxides of gold and certain types of silver that have endothermic properties.

The present invention deals with the use of the former type of gold as a catalyst, and a currently pending invention titled "Silver oxide for discharge-driven carbon dioxide laser" uses silver oxide as a catalyst.

Although gold does not catalyze the CO--O reaction, it does catalyze the reaction between co and at least some high-energy forms of oxygen. The reactions that can occur here are as follows.

Au CO+03 CO□ +O2+ Au G O+ N OCO, + N + eGold catalyzes the formation of CO□ at ambient temperature when used correctly;
The catalytic action of gold is fast enough to match the decomposition rate of C02 in the laser. Gold can also be formed into a highly adhesive film that will not flake off when deposited inside the laser.Gold's electrical conductivity and high reflectivity prevent the problems described below when used on walls facing the discharge. will occur.

FIG. 1 is a flowchart showing the reaction steps when gold is used as a catalyst. The first step 10 is to prepare a tubular container containing the laser gas and a portion called the laser amplification space. This is the space where stimulated emission takes place. A light beam (laser beam) is generated in this space, and at least a portion of the discharge is constantly generated. In addition to the standard configuration of a carbon dioxide laser, a special gold-coated surface is installed. As discussed below, this gold is formed and placed in place to serve as a catalyst.

Step 11 in FIG. 1 shows a process in which CO2 is decomposed by discharge. 6 Decomposition proceeds at a speed determined by factors such as current density, gas pressure, and gas composition ratio.

Typically, in a continuously operating laser, this rate of decomposition is such that the half-life of the CO2 molecule is on the order of 0.1 seconds to several seconds. Eventually, chemical equilibrium is reached, but this equilibrium is not reached until approximately 60% of the C02 has decomposed.

Of course, the decomposition of CO2 has negative consequences for the laser power, gain, efficiency, and discharge stability. It can also be considered as a step. Since CO is stable, transporting it to the gold surface (step 12) is a simple matter for boat fishing. However, atomic oxygen (block 13) has a limited lifetime. Atomic oxygen combines with other atomic oxygens to form 02 (block 14), but this requires a third object, such as a wall, which causes the collision of the three substances in the gas phase. do.

If 02 is still present during the discharge, it decomposes into atomic oxygen (reverse arrow in step 13) or produces other forms of high-energy oxygen (step 15). The energetic oxygen eventually reaches the gold (step 16) energetic oxygen by diffusion or conduction. At the gold catalyst surface, some high-energy oxygen oxidizes the CO to CO2 (step 17), which is returned (by diffusion or conduction) to the intramural space in step 18. This causes the CO2 to become the C in the gas mixture.
It is replenished as O2 and the cycle begins again.

It should be noted that in FIG. 1, step 11 is a disassembly step. The other steps are the disassembled C
It includes a step of resynthesizing O2.

Ideally, all steps other than step 11 proceed at a much faster speed than step 11.

Fortunately, this is possible with a gold catalyst placed at an appropriate location in the laser. In addition, if the gas does not reach the gold catalyst due to separation from the discharge area, this step is performed at 02.
It eventually stops at step 13, where .

Figures 2.3 and 4 show three different types of lasers. However, these drawings have similar a1@
There is a part with . Therefore, if it is important to understand the similarities, please refer to the related codes (30A, 30B, 3
0C1 etc.).

Figure 2 shows two methods of using a gold catalyst. In Figure 2, 2OA indicates a sealed-off type or low-speed gas flow type (pump not shown) carbon dioxide laser. The cathode 21A and anode 22A are the power supply ( (not shown). In this laser, the outer periphery of the inner tube 23A is surrounded by the outer tube 24, water or other cooling fluid is flowed into the space between the tubes 23A and 24, and the cathode 21A is connected to the tube 26 by means of a tube 26.
3A, and the anode 22A is connected to the tube 2 through the tube 25.
Connect to 3A (laser resonator).

A mirror 27,28 is placed at the end of the tube 23A.

A laser gas mixture such as CO2, N2 and He (otherwise CO and Xe) is introduced into tubes 23A, 25.26 and mirror 2.
7. Enclose in the space formed by 28.

When power is supplied to electrodes 21A, 22A, a discharge 29A is generated in tube 23A. Only a portion of this discharge is shown in FIG. 2 to avoid confusion with the catalyst shown in FIG. In FIG. 2, the amplified space includes pipe 26 of pipe 23A and pipe 2
This is the middle part of the reconnection point with 5. Both the discharge and the laser beam are confined within this space.

To obtain a good effect, it is necessary to place clean gold on the inner wall of the tube 23A facing the amplification space. However, since gold is a good conductor of electricity, it must be broken into electrically insulating pieces to prevent the electrical discharge from diverting from the gas and flowing through the gold.

If this discharge could not be prevented, one end of the gold would become a cathode and the other end an anode.

The cathode drop in a Co2 gas mixture is about 450 V, so if the insulated gold pieces are each small enough and the voltage gradient across each piece of gold is less than 450 V, the discharge will not flow through the gold; the voltage gradient will vary. Although it depends on various factors, it is typically 100V/cm. The gold in this example has a length along the voltage gradient of 4 to avoid deflection of the discharge.
．． Should be shorter than 5 cm.

However, in reality, it is preferable to make the gold much smaller than this limit; in a preferred embodiment, the length of the insulated gold along the voltage gradient is less than or equal to the collar of the tube diameter.

In addition to the electrical requirements mentioned above to disrupt the gold, optical requirements are required to prevent undesirable stray reflection lasing effects that reduce output. Parting the gold also results in an optical loss that satisfies this optical condition.

Returning to Figure 2, rings showing gold 30K, 30L, 30M
etc. are installed on the inner periphery of the pipe 23A.

As can be seen from this figure, the rings are spaced apart from each other so that the length of the rings along the axis of the tube 23A is approximately the diameter of the tube. These rings can be coiled from a resilient metal such as gold-plated nickel. These rings are held in place within the tube by friction due to the elasticity of the metal.

Another embodiment is shown in the left half of tube 23A in FIG. 2, where the collection of small dots shown is 11130A. This is a fine gold powder coating on the IIA microscopic scale. There is no electrical conductivity along the surface of the coating. Although this coating appears continuous to the eye, it is not a mirror surface. It is microscopically fine. The processed gold powder exhibits a bright brown color with active reflection. The method for forming this film is as follows. In the process of forming microscopically refined coatings, the refinement occurs as a result of the coating process resulting in a finely divided catalyst such as 3OA. On the other hand, macroscopically fragmented catalysts such as 30K, 30L, and 30M are produced by special processes. In either case, the provision of a section or gap is included in the preferred embodiment.

It is desirable that the area facing the amplification space be coated with gold as widely as possible without the risk of becoming too reflective and producing stray laser reflections; however, small areas of coating may also work well. However, if the gold is distributed along the length of the expansion space, it will work well if only 15% of the area facing the expansion space is covered.

All gaps in the direction parallel to the tube axis should be narrower than the tube diameter.

Figure 3 shows part of a gas cross-flow type carbon dioxide laser.
In the figure, the discharge is shown at 29B between electrodes 21B and 22B, and power is supplied to the electrodes from conductors 43B and 44B.

These electrodes are supported by structure 40. fan 46
serves as a pump to circulate the laser gas into the closed flow path shown by the arrow. The structure 47 constitutes this closed flow path. Multi-channel structure 49 is coated with gold catalyst 30B. This multi-channel structure 49 also functions as a heat exchanger for gas cooling.

As both a heat exchanger and a catalyst need to be brought into sufficient contact with the gas, it is desirable to combine these functions, but it is not necessary to do the same as in 30B.
Since there is no voltage gradient nearby, there is no problem even if 30B is coated with gold, which is a good electrical conductor.

Since it is desirable to capture as much high-energy oxygen as possible to improve the conversion efficiency of the catalyst, the gold catalyst 30B was placed close to the discharge port of the discharge region.

Although a laser mirror is not shown in FIG. 3, the laser mirrors are installed facing each other across the discharge space 29B.

A laser mirror is a part of the bulb container that encloses the laser gas.

FIG. 4 shows a part of an RF waveguide laser in cross section. However, FIG. Also included in FIG. 4 is a high 7 svect ratio rectangular parallelepiped space as shown in the application "Magnetic Enhanced Discharge for Lasers" published by J.D.

In FIG. 4, 21C and 122C indicate electrode plates. In a waveguide laser, the electrode plates 21C and 21C are made of these metal flat plates.
Power is supplied to 22C from terminal 43C to discharge it. The electrode plate 22C is grounded as shown. The electrode plate of FIG. 4 merely shows the appropriate shape of the electrode plate for other lasers in which the discharge occurs laterally (whether AC, DC or pulsed). 23D
The surfaces of the insulators 23C123D, which are ceramic-like insulators, looking into the amplification space are 30C130 and 30C130, respectively.
Indicated by 0.

As will be described later, in the embodiment, a gold catalyst is provided on these surfaces 30G and 30D. The small dot on the surface 30C of the insulator 23C in FIG. 4 indicates the same fine gold powder as 3OA in FIG.
The inner surfaces of the electrode plates 51, 52 may be coated with gold, but this would reduce the catalytic action since they would also be used as electrodes.

A modification of FIG. 4 is obvious to those skilled in the art. For example, if the insulator 23C123D is expanded in a direction parallel to the electric field gradient, it can be formed into a rectangular parallelepiped similar to the discharge space of the other application mentioned above. Can be done. Also electrode plate 21C122C
If the electrode shape is shaped like a number of pins used in a T-type laser, the surface of the insulator between the pin electrodes can be coated with a gold catalyst.

The catalytic effect of gold is CO2, N2. The color of the He discharge changes depending on the amount of decomposition products (mainly CO) in the gas mixture, so if the visible 0 decomposition is less than about 25% of the CO2, the color of the discharge is usually pink and the 1 decomposition ratio is As it increases, the color of the discharge becomes white.

The first experiment in which the catalytic effect of gold was successfully demonstrated was 7.5 cm long, 1.2 cm wide, and 0.0125 cm thick.
Au2 is made by adding a small amount of water to the surface of a brass piece.
A thin film of No. 03 was formed. A paste made by kneading Au203 was spread thinly on the surface of a brass piece and dried.
Next, when this is exposed to Co gas, Au203 is reduced to finely divided gold black. Heating may be used to reduce Au203.

This brass piece is wound into a ring shape with the gold side facing inside, and a second
They were installed at intervals between 30K, 30L, and 30M in the diagram. Inside the sealed tube, 0027%, N213%, H
When a gas mixture of 80% e was sealed at a pressure of 121-bar and a current of 40 mA was passed through it to discharge it, the area where the ring was installed turned pink. However, when a portion of the tube was intentionally left without the gold-coated ring, this area exhibited a white discharge indicating gas decomposition.

We also experimented with a different form of gold catalyst than the one mentioned above. When a total oxide is formed on a ceramic sheet and reduced by heating to 300°C, gold black can be formed. Although this acts as a catalyst.

This ceramic sheet, which conducts electricity well, is further heated (a
From OO°C to 1100°C), the gold was found to turn light brown or perhaps reddish brown, depending on the coating and heating steps. This is when gold melts on the surface of a ceramic sheet and becomes very small, independent particles. This form of gold is excellent as a catalyst because it has both durability and insulating properties. Electroplating very pure gold onto a piece of nickel also produces an excellent catalyst. However, contaminants such as oily fingerprints and imperfect electroplating techniques can degrade the quality of the catalyst.

In addition to visual observation as mentioned above, there is also a method of confirming catalytic activity using an infrared gas analyzer, but as a result of these observations and tests, it was found that in the discharge space where there is no contact with the gold catalyst, It was found that approximately 60% or more of the CO2 during discharge was decomposed. However, if the discharge space is surrounded by a group of electrically insulated gold strips, less than about 15% of CO2 will be decomposed during discharge. A heat-resistant glass discharge tube with an inner diameter of 28 mm was used in the test. Money is 12
Six ceramic pieces of X150X0.5 (unit: mm) were coated, and these six ceramic pieces were formed into a hexagonal tube that could be tightly inserted into the inner circumference of the heat-resistant glass discharge tube with an inner diameter of 28 mm. . When this ceramic is heated to about 900°C, the gold on the surface becomes finely divided. A discharge is passed through the center of the hexagonal tube with the gold surface facing inward.

When gold is directly coated on the inside of a heat-resistant glass discharge tube,
It becomes difficult to maintain the reaction rate due to the catalyst to be higher than the decomposition rate due to the discharge. When a large number of gold strips are attached to the inner wall of the discharge tube.

It is preferable to add Co, H1 deuterium, etc. to enhance the action of the catalyst.

There have been so many techniques for coating gold since ancient times that it is impossible to describe them.

However, since good results have been obtained with finely divided brown and red gold and gold with a mirror-like metallic luster, there does not seem to be a preferred form of gold, and those skilled in the art do not know how to handle gold. I know a lot. These include, for example, chemical deposition from solution, gold chloride reduction methods, electroplating, mechanical deposition, vapor deposition, and sputtering.

The gold coating method of the present invention includes, in addition to these known methods,
The inner circumference of a glass cylindrical tube is coated with gold, which is an excellent catalyst, by sputtering.1 In the present invention, a gold cathode is slowly moved inside the cylindrical tube, and ions collide with the gold cathode to sputter the gold. First, gold is deposited inside the cylindrical tube. Gold sputtered in this way has a golden or dark blue color, but when the deposited gold is heated, it changes color from gold to bright pink. This indicates that the gold has become finer.

According to the hypothesis that led to the experiments using gold as a catalyst, vJ
A single layer of 00 molecules is formed on the flat gold surface, and the high-energy oxygen generated during the discharge transfers the excess energy to the third layer.
It is thought that the gold, which acts as an object, binds to the 00 molecules in a single layer.

As an experiment to undermine this hypothesis, we introduced air and helium instead of the usual CO2, N2, and He mixture into a discharge tube equipped with a gold catalyst, and the gold temporarily became catalytic. It was observed that the C.O.
In a mixture of 2, N2, and He, gold has almost no catalytic activity when discharge begins after the catalytic activity has decreased, but if exposed to the discharge for 30 seconds, gold recovers its catalytic activity and becomes active after about 10 minutes. The catalytic effect is almost completely restored. According to the hypothesis in F., this is because a single layer of oxygen is initially formed on the gold surface, and it is thought that Go recovers and replaces the single layer of oxygen.

However, to quickly maximize chemical activity, the gold surface must be activated by placing a gold catalyst in the discharge gas to actively remove the monolayer of oxygen and water vapor. Good, Co2. N2. If placed during discharge of He mixed gas,
The same goes for a mixed gas of only aN2 and He, which can be removed in a few seconds, and also for Co2. N2. A mixture of He and a small amount of CO may be used, but in that case, it cannot be removed as quickly as with other mixed gases.

A slightly excessive amount of CO is suitable as a mixed gas for a carbon dioxide laser. Generally, when gold is also used as an electrode, most of the ions from the discharge are transferred from the gold surface to CO2.
Gold cannot be a good catalyst because the CO2 is removed and occupies the surface of the gold.This attraction of ions to the electrode destroys the single layer of CO and inhibits the catalytic action of the gold.

In carbon dioxide lasers, the resonator mirror has been coated with gold since its invention. However, the gold-coated mirror had no measurable catalytic effect due to its location relative to the laser amplification space. As mentioned in the explanation of Figure 1, the lifetime of high-energy oxygen is short, and there is no electrical discharge near the gold mirror, so high-energy oxygen cannot reach the surface of the mirror, and even if high-energy oxygen Even if it reaches the mirror of Just giving, away from the mirror, step 12
．． The probability that 13.15 will occur decreases at a rate proportional to the square of the diffusion distance.

This also explains why it is preferable to distribute the gold catalyst along the entire or at least most of the surface facing the amplification space.

In other words, the decomposition in step 11 occurs in the entire discharge space. The speed at which the steps shown in FIG. 1 proceed is such that, in a diffusion-limited laser, the catalytic action can only be as fast as the decomposition rate if the diffusion distance is short enough.

Up until now, the explanation has centered on carbon dioxide lasers, but the idea of the present invention is to use materials other than carbon dioxide lasers, such as platinum and palladium, at temperatures (approximately 300
This method can also be applied to cases where CO2 is generated at a temperature lower than 10°C.

What is important here is 1) a source of Co, 2) a source of high-energy oxygen, 3) a surface coated with gold that has catalytic activity, and 4) a source of high-energy oxygen that coats this gold-coated surface. considering the lifetime of the gas and the speed of gas movement, and placing it close to the source of high-energy oxygen so that it can collide with the high-energy oxygen.

As a source of high-energy oxygen, any source capable of imparting energy to molecules containing at least one oxygen atom to produce the above-mentioned high-energy oxygen is sufficient. (Other electromagnetic waves with wavelengths below the tome and even higher energy) and subatomic particles smaller than atoms and moving at high speed, such as alpha particles, neutrons, protons, and electrons, are also sources of energy for high-energy oxygen.

Additionally, certain other molecules can be oxidized using such gold catalysts and energy sources such as gas discharges or ultraviolet light. These other molecules are 0.1
The molecule would need to meet the criteria of being gaseous at pressures above Torr, having oxygen atoms in the molecule, and positioning the oxygen atoms in such a way that they can attach to the gold.

Although the description has focused on laser oscillators so far, the present invention is equally applicable to laser amplifiers. Therefore, to encompass both of these, the term laser device is appropriate, in addition.

Up until now, the gas used in carbon dioxide lasers has been C02.

N2. I have explained that it is a mixed gas of He.

This is just one example; other gas mixtures, such as CO2, Co, and He, are commonly used in sealed-off lasers. In addition to this, xe, H2O, D2, A
The present invention can also be applied to carbon dioxide lasers using these or other mixed gases.

Although the embodiments described above are preferred, other embodiments may be applied within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the chemical and mechanical steps of an embodiment of the present invention. FIG. 2 is a side view of a typical carbon gas laser embodying the present invention, shown separated into two parts to illustrate two different catalyst arrangements. FIG. 3 shows a typical gas 70-
FIG. 2 is a perspective view of a carbon gas laser. FIG. 4 is a partially cutaway perspective view of a waveguide laser according to an embodiment of the present invention. Agent Maki Tonbe (and 3 others) F/θ/

Claims (1)

[Claims] 1. A mixed gas for a carbon dioxide laser is sealed in a cavity of a sealed tube, and a power source for causing a discharge in the mixed gas and a laser beam for passing through at least a portion of the discharge. In a carbon dioxide laser device, the part of the discharge radiated by the laser beam becomes a laser amplification space, the insulator forming a boundary of at least a part of the laser amplification space. supporting gold in direct or indirect contact, the gold forming a plurality of mutually insulated segments and extending into at least a portion of the laser amplification space;
A carbon dioxide laser device characterized by exhibiting a catalytic action on the mixed gas. 2. producing at least one form of high-energy oxygen, placing a gold-coated surface in a position that facilitates access to both CO and the high-energy oxygen, and catalyzing the gold to produce CO_2; A carbon dioxide gas regeneration method characterized by: