JPH05180954A - Method and apparatus for inducing thunderbolt with laser - Google Patents

Abstract

PURPOSE:To ensure the safety of buildings, information processing equipment and the like without any interference with tree facilities at the surrounding areas by positively inducing thunderbolt from thunder cloud to a lightning arrester. CONSTITUTION:An electron beam 12 is made to enter into a resonance device from a free-electron laser-light generator 8. The part between resonance mirrors 14 and 14' is resonated with a wiggler 13. Thus, free-electron laser light 15 is taken out and emitted toward thunder cloud 3 through the tip of lightning arrester 2 by way of optical systems 16 and 17. Plasma is formed through dielectric breakdown of air in a plasma zone 5. The thunderbolt is induced from the thunder cloud. At this time, the focal point of the laser having the high power density is made to be the variable focal point by changing the wavelength of the free-electron laser light. The focal length is changed in time, and the focal point is made to continue in space. Thus, the plasma channel, which is as long as possible, is directed toward the thunder cloud from the tip of the lightning arrester 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The disclosed technology belongs to the field of technology for inducing lightning with a laser in order to avoid damage to various electric and electronic equipment from lightning.

[0002]

2. Description of the Related Art As is well known, the development of human beings depends on social and personal activities, which are performed day and night without interruption. Activities in the area have become popular, and the thing that guarantees the activities at the time and place where sunlight does not spread is largely due to the electric energy used for lighting, etc. There is no doubt that it is the electric energy that supports the civilization of recent times.

[0003] Thus, the kind of electric energy is supplied from various power plants, and not only the production equipment but also the information industry, the education, and the entertainment life are greatly expanded recently due to the advanced development of computers and the like. I support you.

Therefore, if the supplied electric energy is interrupted due to a power outage or the like due to various causes, it impairs industrial society and civil society and significantly hinders their activities.

By the way, such interruption of electric energy is often caused by a large-scale intensive disaster such as an earthquake or a typhoon, but as is often known empirically, troubles due to lightning strikes occur frequently. is doing.

[0006] For example, when a lightning strike occurs in a high-voltage power line or a substation in the winter, the device mechanism may be destroyed or damaged due to a short circuit, a spark, or the like in various electric facilities, which may have a significant adverse effect. With the recent expansion of various OA devices such as computers, communication and information processing are actively carried out, so if the operation of such OA devices is unexpectedly interrupted due to a power outage due to a lightning strike, data processing may be hurt, Not only does the stored data and records be lost and suffers significant financial damage, but it may also be difficult to recover.

In order to deal with this, various electric facilities and information processing mechanisms are equipped with a power storage device, an in-house power generation device, etc. so as to be switched promptly, but basically, the lightning protection technology has priority. Therefore, various facilities are always equipped with lightning protection facilities such as lightning rods.

As is well known, lightning strikes are a kind of natural phenomenon, and various analyzes and studies have been carried out in combination with meteorology, but the thundercloud that is the source of lightning has an altitude of several hundred meters. Since lightning strikes occur in the upper layers of several thousand meters from the ground, and lightning strikes occur at the shortest distance from the thundercloud on the ground, etc. There is a possibility that lightning strikes may occur not only in areas of high intensity but also in other pointed parts, so research and development is being conducted on technology to more proactively induce thunderclouds than such natural lightning strikes. Is coming.

For example, there is also a technique for launching a light and small rocket from the vicinity of the lightning protection facility against the occurrence of a thundercloud and raising an electric wire or the like together with the rocket to a position as high as possible in the upper layer to induce lightning. Has been devised.

[0010]

However, since the lightning strike is a natural phenomenon as described above, launching a rocket or the like in response to the occurrence of a thundercloud is ad hoc and it is difficult to take prompt measures. However, there is a disadvantage in that a raised wire may come into contact with trees, electric wires, buildings and the like in the vicinity due to a gust of wind or the like caused by lightning.

There has also been a problem that it is extremely difficult to always maintain the maintenance state in which the rocket can be launched so that the rocket can be immediately launched.

To deal with this, a laser beam is formed in a short circuit between the tip of the lightning rod and the thundercloud, and the power between the laser beam causes the air between the thundercloud and the lightning rod to be dielectrically broken down to generate plasma. A technique has been devised that positively induces lightning protection equipment by the high conductivity of the plasma.

Since plasma generation through dielectric breakdown of air by the laser light does not occur unless the power density of the laser light is high, it is necessary to focus the laser light to increase its power density. It is conceivable to narrow the focal length of the laser light for focusing.

The energy limit for converting air into plasma is 0.3 GW / cm ² when the pulse width is 50 ns.

However, as a matter of course, there is a contradiction that the power density of the laser beam becomes large when the depth of the focal length is physically small, and conversely becomes small when the depth of the focal length is physically long. The target laser light is, for example, carbon dioxide gas laser light, but the wavelength is fixed at, for example, 10.6 microns.
Therefore, the focal length cannot be changed with time.

By the way, the generation of plasma through the dielectric breakdown of air by laser light is based on the fact that lightning from a thundercloud is arrested by the conductivity of the plasma. As in the case of raising the current-carrying wire due to (1), the longer the plasma channel is (normally 100 m is required), the better the lightning protection effect is expected.

Therefore, a gas laser such as a carbon dioxide gas laser that has been conventionally developed has a potential effect of lengthening the plasma channel, but since the wavelength is fixed, it is possible to use an optical system such as a lens. It is not possible to increase the focal length of, and as is well known, a thundercloud is a gas in which water vapor and water droplets are mixed in a high concentration, and the state is also different, Therefore, the conditions for plasma generation via dielectric breakdown are variously different, and there is no freedom to select a laser beam having an optimum wavelength that leads to plasma generation via optimum dielectric breakdown.

By the way, the plasma through the dielectric breakdown of air is in units of microseconds from its generation to its extinction, but the lifetime from the generation of the laser to its extinction is hundreds to thousands of times shorter. , By changing the focal length, which is the high plasma density portion of the laser, in an extremely short time, the high power density focal points will be spatially homogenously continuous. The plasma channel will be formed continuously, and the lightning protection path from the thundercloud will be formed.

However, since the conventionally developed technique using a gas laser is a fixed focus system, plasma having a high laser power density is only formed only before and after the vicinity of the focus, and the plasma channel is as long as possible. There is a drawback that is impossible to generate.

[0020]

OBJECT OF THE INVENTION The object of the invention of this application is to solve the problem of in-air formation of a plasma channel through dielectric breakdown of air by laser light based on the above-mentioned prior art, and to solve the problem. By adopting the variable focus method by using the freedom of selectivity of, the focal length with high plasma density is changed with time in the vicinity of the focus to form a spatially continuous plasma channel as long as possible, and It is possible to use the laser of the wavelength most suitable for the weather conditions from the lightning protection facility to the thundercloud, that is, the dielectric breakdown in the gas of the thundercloud and the plasma formation. It is intended to provide a laser-induced lightning method and a device used directly in the method.

[0021]

In order to solve the above-mentioned problems, the structure of the invention of this application, which is based on the above-mentioned object, is provided in various devices, structures, etc. in order to solve the above-mentioned problems. When a thundercloud is generated on the existing lightning protection facility and a lightning strike may occur, a predetermined free electron laser beam is generated by a free electron laser generator fixedly attached to the lightning protection facility to operate a predetermined optical system. It is radiated in a direction in which the tip of the lightning protection facility and the thundercloud are short-circuited via the laser, and at that time, the laser between the lightning protection facility and the thundercloud is most likely to cause dielectric breakdown, and a wavelength at which plasma is likely to form (100 μ
m), which uses free electron laser light so that the focal length can be changed in general (a thin metal plate is used to change the curvature of the mirror by electrically vibrating the central part) Between the thundercloud and the tip of the lightning protection facility by changing the wavelength of free electron laser light in a time much shorter than the extinction time from the plasma generation by condensing with a lens made of a substance whose refractive index differs depending on the wavelength By forming the plasma channel with the longest possible spatial length by changing the focal length of the laser beam over time, the plasma channel with high laser power density can be formed by forming a conductive path from the thundercloud to the lightning protection facility. It is a technical measure that makes it possible to prevent lightning.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description will explain one embodiment of the invention of this application.

The illustrated embodiment is an embodiment of the laser lightning striker 1. For example, a lightning cloud 3 generated (attacked) above a lightning rod 2 of a lightning protection facility provided in a facility such as a nuclear power plant is free. Electron laser light 4 is short-circuited between the lightning rod 2 and the thundercloud 3 to insulate the air between them to form a plasma zone 5 and form a conductive plasma channel 6. A focusing coil 10 is provided outside an accelerating tube 9 connected to a generator 8 of the laser light generator, and a cathode 11 emits an electron beam 1
2 (the illustrated embodiment is a schematic diagram) is injected between the wigglers 13 of the resonance device to generate free electron laser light (FEL) 15 between the resonance mirrors 14 and 14 'and is extracted from one resonance mirror 14'. In order to form a predetermined focal length between the tip of the lightning rod 2 and the thundercloud 3 of the lightning protection facility, the light is condensed by the reflecting mirror 16 through the lens 17 having a wavelength dispersion function which constitutes an optical system in this embodiment. The light is focused on the surface of the plasma zone 5 and the surrounding air is dielectrically destroyed to dielectrically destroy the air in the plasma zone 5 to form plasma.

As described above, the free electron laser light is not limited to a single wavelength, but a continuous wavelength can be selected in a predetermined manner as compared with the gas laser light. Therefore, the generator 8 of the free electron laser light generator can be selected. By electrically controlling the electron accelerating voltage and changing the wavelength so that the extinction time from plasma generation is short, the chromatic aberration changing function corresponding to the wavelength change in the lens 17 having the wavelength dispersion function is used. The focal length changes in an extremely short time by changing the focusing function, and the change in the focal length changes in a cycle shorter than the plasma extinction time. A varying plasma channel 6 will be formed, and therefore a high power density plasma plasm at each wavelength or cycle-by-cycle focus. The channel is formed between the tip of the lightning rod 2 and the thundercloud 3 as much as possible, and the conductive path of the lightning is formed from the thundercloud 3 to the tip of the lightning rod 2 like the conductive wire by the rocket described above. Therefore, lightning protection will be exposed.

Incidentally, instead of the lens 17 of the optical system having the wavelength dispersion function of the embodiment, an optical system may be used, and a mirror having a function capable of changing the focal length with time may be used.

In practice, however, it is scientifically and optically difficult to form the plasma channel 6 over the entire length between the thundercloud 3 and the tip of the lightning rod 2 in units of several hundreds or thousands of meters. However, since the plasma channel 6 having the longest possible size can be formed from the tip of the lightning rod 2 toward the thundercloud 3, the lightning strike from the thundercloud 3 is relatively far from the ground surface. Since lightning is selected by selecting a short path, lightning protection is sure to appear.

[0027]

As described above, according to the invention of this application, it is possible to prevent mechanical and mechanical destruction or damage to various electric devices in a power transmission facility or a building by lightning protection from a thundercloud that naturally occurs spontaneously. Not only does this not hinder the calculation, control and operation of information processing devices such as various office automation equipment,
Further, there is an excellent effect that it is possible to prevent the stored or recorded data from being erased.

There is no risk of contact with surrounding trees, power lines, buildings, etc. due to launching of conductive wires by a rocket, etc. Since it only needs to be pointed at the thundercloud from the tip of the lightning protection facility, there is no hindrance to the surroundings and so on, and it is possible to induce a lightning strike.

Further, not only can the lightning strike be triggered by forming a plasma having good conductivity by dielectric breakdown of the air in the space between the lightning strike facility and the thundercloud by the laser light, Since a continuous wavelength, which is a characteristic of free electron laser light, can be used when forming a focus with a high laser power density in order to form a plasma by dielectric breakdown of the air, a lens with a wavelength dispersion function and a focal length can be temporally set. An optical system such as a mirror that can change the wavelength can change the wavelength in a time much shorter than the extinction time from the generation of plasma, so the focal length is changed over time to form a spatially continuous focus. Therefore, it is possible to form a plasma channel as long as possible from the tip of the lightning protection facility toward the thundercloud. , Are achieved optimal wavelength superior effect can be formed with a laser beam to produce a dielectric breakdown of the space of the gas to the lightning protection facilities as a mixed gas containing water vapor at a high concentration.

Therefore, there is a security advantage that it is possible to induce lightning protection from higher thunderclouds and to preserve the functions of various facilities and information processing devices in advance.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the system of the invention of this application.

[Explanation of symbols]

 2 Lightning protection facility 3 Thundercloud 4 Laser 5 Plasma zone 15 Free electron laser light 16,17 Optical system 6 Plasma channel

Claims (6)

[Claims] 1. A laser-induced lightning method in which a laser light from a laser light source is condensed between a grounded lightning protection facility and a thundercloud, and the surrounding air is dielectrically destroyed to generate plasma to induce a lightning strike. In the above, the free electron laser light is used as the laser light, and the focal length of the laser light is temporally changed through an optical system so as to be spatially continuous, so that the plasma channel becomes a thundercloud from the lightning protection facility as much as possible. A method of laser-induced lightning, characterized in that it is designed to be directed. 2. The laser lightning strike method according to claim 1, wherein a laser beam of 100 μm having a wavelength that easily turns air into plasma is used as the wavelength of the free electron laser beam. 3. The laser-induced lightning method according to claim 1, wherein the wavelength of the free electron laser light is changed with time. 4. A laser lightning strike method in which laser light from a laser light source is focused between a grounded lightning protection facility and a thundercloud, and the surrounding air is dielectrically destroyed to generate plasma for lightning strike. In the device used for the laser induction device, an optical system mechanism is provided on the optical axis of the free electron laser light generator between the tip of the lightning protection facility and the thundercloud. Lightning device. 5. The laser lightning striker according to claim 4, wherein the optical system mechanism is a lens having a wavelength dispersion function. 6. The laser lightning striker according to claim 4, wherein the optical system mechanism is a mirror having a function of changing the focal length with time.