JP2001116892A - Method for decontaminating surface layer of inorganic layer by use of laser beam and high-pressure gas and apparatus for use therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decontaminating method for decontaminating surface layers of inorganic materials, starting from concrete, contaminated with harmful matter, without exposing operators to laser beams nor causing secondary contamination to the surroundings, noises and vibration, and an apparatus excellent in controllability for use therein. SOLUTION: The method for decontaminating the surface layers of inorganic material by use of laser beams and high-pressure gas comprises: (a) a laser beam irradiation process in which the contaminated portions of the surface layers of inorganic material contaminated with harmful matter are irradiated with laser beams to sequentially melt the contaminated portions; (b) a high-pressure gas ejection process in which the high-pressure gas is ejected to the melted layers, i.e., the contaminated portions melted through the laser beam irradiation process, to sequentially crush the melted layers into particles of contaminants; and (c) a contaminant powder recovery process in which the powder of contaminants produced from the melted layers through the high-pressure gas ejection process are sequentially recovered. The apparatus for use in the method is also disclosed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decontaminating a surface layer of an inorganic substance using a laser and a high-pressure gas and an apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, in nuclear facilities such as nuclear power plants and nuclear laboratories, and radioactive materials handling facilities such as hospitals, radioactive materials such as fission products are deposited on the surface of inorganic materials such as concrete and mortar in the facilities. In the case of infiltration and contamination, a method has been adopted in which a worker wears protective clothing, removes the contaminated portion by mechanical polishing / grinding means such as a breaker, a scabber, and a planar, and decontaminates. In addition, the same method may be used when contamination is caused by harmful chemical substances.

[0003]

However, these mechanical methods have the following problems. 1) During work, contaminated concrete and the like will be scattered in large quantities as fine powder, exposing workers and causing secondary pollution. 2) Mechanical polishing / grinding is difficult to remove according to the depth of contamination penetration. 3) The tool is contaminated because the tool directly contacts the contaminated surface. 4) These operations involve a large reaction force, which generates noise and vibration during the operation, and the equipment used for them requires high rigidity. 5) It is difficult to remotely control mechanical polishing and grinding equipment.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and eliminate the need for exposure to workers, secondary pollution to the surroundings, and the occurrence of noise and vibration, and to facilitate remote operation. An object of the present invention is to provide a decontamination method excellent in performance and an apparatus used for the method.

[0005]

Means for Solving the Problems In order to achieve the above object, according to the first aspect of the present invention, (a) a laser is applied to a contaminated portion of an inorganic material surface layer contaminated by a harmful substance, and the contaminated portion is irradiated with a laser. A) a high-pressure gas injection step of injecting a high-pressure gas into the molten layer, which is a contaminated portion melted by the laser irradiation step, to sequentially turn the molten layer into contaminant powder, (c) A method for decontaminating an inorganic substance surface layer using a laser and a high-pressure gas, comprising a contaminant powder collecting step for sequentially collecting the contaminant powder generated from the molten layer by the high-pressure gas injection step, is proposed. According to this method, since the decontamination is performed in a non-contact manner, there is no vibration or the like, the rigidity of the apparatus can be reduced, the safety of workers can be ensured, and the secondary contamination to the surroundings can be prevented.

According to a second aspect of the present invention, there is provided a method for decontaminating an inorganic substance surface layer using the laser according to the first aspect and a high pressure gas, wherein (a) the laser is a carbon dioxide gas laser, and Nd: YAG
A laser or an iodine laser, and (a) the Nd: YAG laser and the iodine laser transmit a laser from a laser oscillator through an optical fiber. According to this, the inorganic material surface layer can be reliably melted.

Further, a method of decontaminating a surface layer of an inorganic substance using a laser and a high-pressure gas, characterized by providing a step of applying a chemical for lowering the melting point of the inorganic substance to a contaminated portion before the laser irradiation step, is proposed. (Claim 3). According to this, the melting point of the inorganic substance is lowered, so that the melting can be performed efficiently.

[0008] Further, in claim 4, a laser irradiation device for irradiating a laser from a laser irradiation head to a contaminated portion of an inorganic material surface layer contaminated with a harmful substance to melt the contaminated portion; A high-pressure gas injection device that injects a high-pressure gas from a high-pressure gas injection nozzle into a molten layer that is a contaminated portion that has been melted by the irradiation of the molten layer to make the molten layer a contaminant powder, and (c) the contaminant generated from the molten layer. A contaminant powder collecting device for collecting powder with a collecting hood, (d) at least the laser irradiation head of the laser irradiating device, the high-pressure gas injection nozzle of the high-pressure gas injection device, and the collection hood of the contaminant powder collecting device. A decontamination apparatus for a surface layer of an inorganic material using a laser and a high-pressure gas, comprising a scanning apparatus that moves in conjunction with the decontamination part and sequentially decontaminates the contaminated portion. According to this device, the contaminated portion can be reliably removed.

Further, there is provided an apparatus for decontaminating an inorganic substance surface layer using a laser and a high-pressure gas according to claim 4, wherein (a) the laser oscillator of the laser irradiation apparatus is a carbon dioxide gas laser oscillator;
d: a YAG laser oscillator or an iodine laser oscillator, and (a) the Nd: YAG laser oscillator and the iodine laser oscillator transmit a laser beam from the laser oscillator via an optical fiber. According to this, the contaminated portion can be reliably melted.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a decontamination operation of an inorganic substance surface layer using a laser and a high-pressure gas according to the present invention. FIG. 2 is a schematic diagram showing melting and explosion peeling of the inorganic material surface layer by laser.

First, a method for decontaminating a surface layer of an inorganic substance using a laser and a high-pressure gas according to the present invention will be described. The decontamination method in the present invention includes a laser irradiation step of irradiating the contaminated portion 1 ′ with the laser 21, a high-pressure gas injection step of injecting the high-pressure gas 31 into the molten layer 2, and a contaminant powder collecting step of collecting the contaminant powder 41. (See FIG. 1).

(A) The laser irradiation step aims at sequentially irradiating the contaminated portion 1 ′ of the inorganic material surface layer 1 contaminated with the harmful substance with the laser 21 and melting the contaminated portion 1 ′ by the heat of the laser 21. I do.

1) In the present invention, harmful substances include radioactive substances such as fission products generated from a nuclear reactor, radioactive waste liquid and plutonium generated from a nuclear facility, and radioactive isotopes such as cobalt 60 handled by medical institutions. It should be pointed out that the invention is applicable not only to radioactive contamination but also to heavy metals and other harmful chemicals.

2) The inorganic substance surface layer 1 refers to a surface layer of concrete (normal concrete / heavy concrete) or mortar, but can also be applied to a surface layer of marble or bedrock. This is because these inorganic substances have similar compositions and are used for pavements, floors, walls, ceilings, etc. of nuclear facilities and hospitals.

3) The contaminated portion 1 'refers to a portion where the above-mentioned inorganic substance is contaminated by the above-mentioned harmful substance, and the contaminated portion is mostly a surface layer portion of the inorganic substance.

4) The laser 21 refers to coherent light having a uniform phase and wavelength. In the present invention, for example, a carbon dioxide laser, a Nd: YAG laser (Yttrium Aluminum)
A laser 21 having a wavelength in the infrared region, such as a Garnet Laser or an iodine laser, is suitable. This is because they are also used for metal processing and the like, and high-powered materials for melting earth and stone by heat are provided. Note that the laser is not limited to the laser as long as it can melt the inorganic substance. Further, these lasers 21 may be used alone or in any combination of different types of lasers. The laser 21 irradiates the contaminated portion 1 ′ in a pinpoint manner, and the irradiated portion is heated and melted by the infrared thermal energy of the laser 21.

Note that, depending on the method of irradiation with the laser 21, the inorganic material surface layer 1 may explode and separate (explosive separation 5) as shown in FIG. 2 (c). In some cases, the high-pressure gas 31 described below may not be able to be sufficiently recovered. Therefore, in the present invention, it is necessary to irradiate the molten gas as shown in FIG. This is adjusted by appropriately selecting the output, beam area, scanning speed, and the like of the laser oscillator 24. For example, ordinary concrete, heavy concrete, and mortar are selected as the simulated contamination layer 1 ', and the output density is 0.4 to 71 (W / square m).
m), output 300-2000 (W), beam area 28-70
Laser 2 at 7 (square mm), scanning speed 30-300 (mm / min)
Irradiation No. 1 was satisfactory. In addition, more favorable melting conditions include an output of 500 to 750 (W), a beam area of 132 to 176 (square mm), and a scanning speed of 60 to 80 (m).
m / min).

(A) In the high-pressure gas injection step, the high-pressure gas 31 is injected into the contaminated portion (molten layer 2) melted in the laser irradiation step, so that the molten layer 2 is sequentially turned into the contaminant powder 41. The purpose is to carry away this contaminant powder 41. The mechanism by which the molten layer 2 becomes the contaminant powder 41 by the injection of the high-pressure gas 31 will be described later.

1) As the high-pressure gas 31, nitrogen gas, carbon dioxide gas, helium gas, argon gas, or the like is used. These gases are inert gases and can easily create a high-speed gas flow. These gases are supplied from gas cylinders and compressors. The high-pressure gas 31 is required to have a role as a coolant gas for cooling the molten layer 2 and a role as a carrier gas for carrying the contaminant powder 41. Incidentally, the greater the specific heat of the gas, the better the ability as a coolant gas, and the greater the density of the gas, the better the ability as a carrier gas. In addition, carbon dioxide has a characteristic that snow of dry ice is easily produced.

2) When the high-pressure gas 31 is injected into the molten layer 2, the high-pressure gas 31 is pulverized into the contaminant powder 41. The mechanism is considered as follows. i) The molten portion is injected by the high-pressure gas 31,
Since it is cooled rapidly, it rapidly solidifies and is instantaneously broken into pieces due to thermal distortion to become the contaminant powder 41.
Also, even if it escapes from destruction, large stress due to thermal strain accumulates inside and solidifies, so if it receives a mechanical shock, it instantaneously shatters, thereby causing a chain of destruction and pulverization Will advance. ii) Alternatively, when the injection speed of the high-pressure gas 31 is increased, the molten layer 2 is directly blown off, and
The molten layer 2 is pulverized by cutting, cooling, solidifying, and thermal strain to become the contaminant powder 41. In other words, the high-pressure gas 31 acts to “solidify, pulverize, and pulverize the molten layer 2 sequentially and remove it as a contaminant powder 41” in i), and “directly blow and separate the molten layer 2 sequentially” in ii). -Cooling, solidifying, pulverizing, and removing as contaminant powder 41 ".

(C) In the contaminant powder collecting step, the contaminant powder 41 which has been pulverized and blown off in the above step is collected.
An object of the present invention is to prevent exposure of workers and to prevent the surroundings from being secondarily contaminated. In this recovery process, the contaminant powder 4 blown off like a so-called vacuum cleaner is used.
It is suitable to use means for sucking and recovering 1.

In the laser irradiation step, the high-pressure gas injection step, and the pollutant powder recovery step, since the irradiation of the laser 21 and the injection of the high-pressure gas 31 are spot-like, a wide range of decontamination of the contaminated portion 1 'is performed at one time. However, by performing the above steps while sequentially moving the place, it is possible to decontaminate a wide range of contamination. In addition, when the contamination extends deeply, it is possible to perform decontamination according to the penetration depth of the contamination by repeating the process.

Further, by applying a substance for lowering the melting point of the inorganic substance, for example, an aqueous solution of sodium chloride containing sodium (Na) to the contaminated portion 1 'before the laser irradiation step, the work efficiency is improved. In addition, a certain effect can be expected even if a solution (such as boric acid water) containing potassium (K) or boron (B) is applied instead of Na as long as it lowers the melting point of the inorganic substance. This is because Na and boron have an effect of lowering the melting point (softening point) of quartz (quartz glass). In fact, when a 26% aqueous sodium chloride solution was applied to concrete, the amount of melting (peeling) was increased by about 10% even with laser irradiation under the same conditions as compared to the case where no aqueous sodium chloride solution was applied.

Next, a decontamination apparatus for a surface layer of an inorganic substance using a laser and a high-pressure gas according to the present invention will be described. As shown in FIG. 1, a decontamination device 10 according to the present invention includes a laser irradiation device 20,
It comprises a high-pressure gas injection device 30, a contaminant powder recovery device 40, and a scanning device (not shown).

(A) The laser irradiating apparatus 20 mainly comprises a laser irradiating head 22 and a laser oscillator 24. The purpose of this apparatus is to irradiate the laser 21 with the contaminated portion 1 'as described above.
And irradiating the irradiated portion with heat.

1) The laser irradiation head 22 is
Plays a role in irradiating the contaminated portion 1 ′ with spots, and it is preferable that the laser irradiation head 22 be installed such that the irradiation area (beam diameter) is minimized with respect to the contaminated portion 1 ′ which is the target. . That is, the target can be irradiated from a perpendicular direction (so-called right above, right below, right next to). Thereby, the contaminated portion 1 'can be efficiently melted.

2) Since the laser oscillator 24 melts the inorganic material surface layer 1 such as concrete by heat, a high-power laser is used. As described above, a carbon dioxide laser oscillator or the like is suitable.

3) The laser transmission path 23 from the laser oscillator 24 to the laser irradiation head 22 uses a mirror or an optical fiber depending on the distance or the type of the oscillator.
In particular, the laser oscillator 24 is an Nd: YAG laser oscillator,
In the case of an iodine laser oscillator, it is suitable to transmit the laser beam to the laser irradiation head 22 via the optical fiber 23. If the optical fiber 23 or the like is used, the laser oscillator 24 can be placed at a remote place, so that a scanning device (not shown) for actually performing the decontamination work can be made small and lightweight.

(A) The high-pressure gas injection device 30 includes a high-pressure gas injection nozzle 32, a pressure regulator 34, a high-pressure gas generator 35, and the like. The purpose of this device is as described above,
i) by rapidly cooling the molten layer 2 to rapidly solidify it, breaking it down by heat shock, pulverizing it, and removing it by blowing it off as a contaminant powder 41; ii) That is, in the air flow of the high-pressure gas 31, it is broken / powdered by dividing / cooling / solidifying / heat shock, and is removed as the contaminant powder 41.

1) The high-pressure gas injection nozzle 32 is provided so as to inject the high-pressure gas 31 into the molten layer 2 from an oblique direction. When the high-pressure gas 31 is injected from directly above the molten layer 2, the contaminant powder 41 is scattered in all directions, so that it becomes difficult to collect the contaminant powder 41. Therefore, the high-pressure gas injection nozzle 32 is inclined and directed so as to inject the high-pressure gas 31 from an oblique direction. In this regard, the laser irradiation head 2
Different from 2. As described above, the high-pressure gas 31 is suitably nitrogen gas, carbon dioxide gas, helium gas, argon gas, or the like.

2) The pressure regulator 34 is a high-pressure gas generator 3
5, the pressure of the high-pressure gas 31 flowing to the high-pressure gas injection nozzle 32 is adjusted.
The flow velocity of the water is determined.

3) The high-pressure gas generator 35 may be a mechanical compressor or a gas cylinder storing high-pressure gas.

4) The pressure regulator 34 is connected to the high-pressure gas injection nozzle 32 by a flexible hose having pressure resistance, for example, a hose 33 made of pressure-resistant rubber.

(C) The contaminant powder collecting device 40 is composed of a collecting hood 42, a separating device 44, a suction device 45, and the like.
The purpose of the present invention is to collect the pollutant powder 41 scattered by the jetting of the liquid and prevent secondary pollution to the surroundings.

1) The collection hood 42 has a funnel shape so that the contaminant powder 41 blown off by the high-pressure gas 31 can be efficiently collected. This is preferably installed with its mouth facing the position opposed to the high-pressure gas injection nozzle 32, that is, the direction in which the contaminant powder 41 is blown off.

2) The separation device 44 separates and collects the contaminant powder 41 blown off by the high-pressure gas 31 from the gas stream (carrier gas), and uses a system used in nuclear facilities. become. In some cases, the contaminant powder 41 contains large fragments, and it takes some time to sufficiently cool the contaminant powder 41. Therefore, a trap portion made of a heat-resistant container is provided in the separation device 44, It is preferable to collect large debris by, for example, temporarily lowering the flow rate of the carrier gas in the trap portion, and separate and collect the fine debris powder 41.

3) The suction device 45 is required for actively collecting the scattered contaminant powder 41. In this case, it is preferable to use a powerful suction device 45 to prevent secondary contamination.

4) The collecting hood 42 and the separating device 4
4 are connected by a flexible hose 43 or the like.
This hose is preferably made of a material having some heat resistance.

(D) The scanning device (not shown) cannot process a wide range of the contaminated portion 1 'at a time because the irradiation of the laser 21 and the injection of the high-pressure gas 31 are spot-like.
It is provided for sequentially decontaminating the contaminated portion 1 'and finally decontaminating the entire contaminated portion.

1) The scanning device includes at least a laser irradiation head 22, a high-pressure gas injection nozzle 32, and a collection hood 42.
Are fixed in a predetermined positional relationship, and by linking them, the contaminated portion 1 'is scanned to decontaminate a wide range of contaminated portions.
The laser irradiation head 22, the high-pressure gas injection nozzle 3
2. If only the collection hood 42 is scanned, the scanning device can be made extremely small and lightweight. That is, the laser irradiation head 22, the high-pressure gas injection nozzle 32, and the recovery hood 42 are much smaller and lighter than the laser oscillator 24, the high-pressure gas generator 35, and the contaminant powder 41 separator 44. Also, this decontamination work, unlike mechanical work such as grinding, has no reaction force at the time of work, so there is no need to give the scanning device a large rigidity,
From this point, it is possible to reduce the size of the scanning device.

2) The scanning device has a self-propelled function and can approach the contaminated site by remote control. If the scanning device is provided with a height adjusting function and a swinging function, decontamination work on ceilings, walls, curved surfaces, etc., as well as on floors, can be easily performed.

3) A laser irradiation head 2 is attached to the scanning device.
When only the laser light source 2 is incorporated, the laser 21 is transmitted between the laser oscillator 24 and the laser irradiation head 22 via a laser transmission path 23 such as an optical fiber or a mirror. In particular, since the optical fiber 23 is flexible, there is an advantage that the laser 21 can be transmitted to any place. A flexible pressure-resistant hose 3 is provided between the high-pressure gas injection nozzle 32 and the high-pressure gas generator 35.
3 and so on. Similarly, the collection hood 42 and the separation device 44 of the pollutant powder 41 are provided with a flexible hose 43.
Are tied together.

[0043]

As described above, the decontamination according to the present invention can be performed in a non-contact manner because of the work by laser irradiation, so that the vibration and noise during the work can be extremely reduced. is there. In addition, in methods such as grinding, a large reaction force is applied to the tool, so it is necessary to increase the rigidity of the device.
In the method of the present invention, it is not necessary to increase the rigidity of the device because of non-contact work. Therefore, it is possible to reduce the size and weight of the device that actually performs the work.

The powdered contaminant powder is blown off in a certain direction, so that it is easy to recover. Compared with the conventional decontamination work by grinding, etc., the exposure of workers and the secondary contamination of the surrounding area are greatly reduced. can do.

The laser irradiation conditions and the high pressure gas injection conditions can be changed in a wide range, so that the work speed and the depth of decontamination can be easily adjusted, and a flexible and flexible method can be used in every situation. Decontamination work can be performed.

Laser irradiation head, high-pressure gas injection nozzle,
In addition, if only the collection hood is provided in the scanning device, the scanning device that actually performs the work can be made extremely lightweight and small, so that it is possible to cope with contamination in any place.

In addition, in the case of this configuration, main equipment such as a laser oscillator installed at a remote place is not directly contaminated. Further, in the case of this configuration, since the scanning device is small and lightweight, remote control is extremely easy. Thereby, the possibility that the worker is exposed to radiation is greatly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a decontamination operation of an inorganic substance surface layer using a laser and a high-pressure gas according to the present invention.

FIG. 2 is a schematic view showing melting and explosion peeling of a surface layer of an inorganic substance by laser. (A) is a figure which irradiates a laser to the inorganic substance surface layer, (b) is a figure which shows fusion peeling, (c) is a figure which shows explosive peeling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inorganic substance surface layer 1 'Contaminated layer (contaminated part) 2 Fused layer 2' Local melting 3 Fused exfoliated layer 5 Explosive exfoliated 6 Explosive exploded layer 10 Decontamination device 20 Laser irradiation device 21 Laser (laser light) 22 Laser irradiation head 23 Laser Transmission path (optical fiber) 24 laser oscillator 30 high-pressure gas injection device 31 high-pressure gas (high-pressure gas flow) 32 high-pressure gas injection head 33 pressure-resistant hose 34 pressure regulator 35 high-pressure gas generator (gas cylinder) 40 pollutant powder recovery device 41 Contaminant powder 42 Recovery hood 43 Hose 44 Separation device 45 Suction device S Scanning direction

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirofumi Kamada 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Wignaraja Shiva Kumaran 1--25, Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 1 Taisei Construction Co., Ltd. (72) Inventor Shunji Sato 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Tatsuya Koga 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Inside Rishi Electric Co., Ltd. (72) Inventor Tomoyuki Yamamoto 2-4 Yotsuya, Shinjuku-ku, Tokyo Shinryo Corporation Industrial Co., Ltd. (72) Inventor Tetsuya Fujita 2-4-2 Yotsuya, Shinjuku-ku, Tokyo Shinryo Corporation F term (reference) 4E068 AA04 CE08 CG01 CH08 CJ01 DB12

Claims (5)

[Claims] 1. A method for decontaminating an inorganic substance surface layer using a laser and a high-pressure gas, comprising the following steps. (A) A laser irradiation step of irradiating a laser to a contaminated portion of an inorganic material surface layer contaminated with a harmful substance and sequentially melting the contaminated portion. (B) A high pressure is applied to a molten layer which is a contaminated portion melted by the laser irradiation step. A high-pressure gas injection step of injecting gas to sequentially turn the molten layer into contaminant powder (c) a contaminant powder recovery step of sequentially collecting the contaminant powder generated from the molten layer by the high-pressure gas injection step (2) The laser is a carbon dioxide laser, a Nd: YAG laser, or an iodine laser. (B) In the Nd: YAG laser or the iodine laser, a laser from a laser oscillator is used as an optical fiber. 2. The method for decontaminating an inorganic substance surface layer using a laser and a high-pressure gas according to claim 1, wherein the transmission is performed by using a laser. 3. A laser and a high-pressure gas according to claim 1, wherein a step of applying a chemical for lowering the melting point of the inorganic substance to the contaminated portion is provided before the laser irradiation step. A method for decontaminating a surface layer of an inorganic substance by using a method. 4. An apparatus for decontaminating a surface layer of an inorganic substance using a laser and a high-pressure gas, comprising: (A) A laser irradiation apparatus that irradiates a laser from a laser irradiation head to a contaminated portion of an inorganic material surface layer contaminated with a harmful substance to melt the contaminated portion. (B) A molten layer that is a contaminated portion that has been melted by the laser irradiation. High-pressure gas injection device that injects high-pressure gas from a high-pressure gas injection nozzle to make the molten layer a contaminant powder (c) A contaminant powder recovery device that recovers the contaminant powder generated from the molten layer by a recovery hood (D) moving at least the laser irradiation head of the laser irradiation device, the high-pressure gas injection nozzle of the high-pressure gas injection device, and the collection hood of the contaminant powder collection device to sequentially decontaminate the contaminated portion; Scanning device (5) The laser oscillator of the laser irradiation device is a carbon dioxide laser, a Nd: YAG laser, or an iodine laser, and (b) the Nd: YAG laser or the iodine laser is used. The apparatus for decontaminating an inorganic substance surface layer using a laser and a high-pressure gas according to claim 4, wherein the laser from the laser oscillator is transmitted by an optical fiber.