JPH1073688A - Neutral particle injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a neutral particle injector capable of uniformly impressing magnetic field to the center of neutralization cell and instantaneously changing the magnetic field to a desired magnetic field when it occurs a change in discharge conditions. SOLUTION: To a tube shape neutralization cell 11, a waveguide 12 guiding a microwave to the neutralization cell 11 is connected. A microwave generator source which is connected to the neutralization cell 11 via the waveguide 12 and generating microwave is not shown in the figure. On the neutralization cell 11, an inlet, which is not shown in the figure, is provided for introducing discharge gas in the neutralization cell 11. Along the outer wall of the neutralization cell 11, a solenoid coil 13 is wound. To the solenoid coil 13, a power source 14 supplying voltage to the solenoid coil 13 is connected. With a neutral particle injector of this constitution, a magnetic field of uniform strength to the inside of the neutralization cell 11 can be penetrated and so plasma can be efficiently generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neutral beam injector, and more particularly to a neutral beam injector used in a fusion reactor.

[0002]

2. Description of the Related Art Neutral particle injector N used in nuclear fusion
The BI (Neutral Beam Injector) ion beam
A negative ion beam of hydrogen or deuterium (H ⁻ , D ⁻ ) is used.

Hereinafter, the configuration of a conventional neutral particle injector will be described with reference to the drawings. FIG. 6 is a cross-sectional view of the neutral particle injector. For example, a deuterium gas is previously introduced into the discharge chamber 1 and the negative ions D of the deuterium are discharged by the discharge.
^- is generated. The generated negative ions are extracted to the outside of the discharge chamber 1 from a plurality of ion extraction holes formed in a plurality of extraction electrodes 2 provided in the discharge chamber 1. A predetermined voltage is applied to each of the plurality of extraction electrodes 2,
As the negative ions pass through the extraction electrode 2, they are gradually accelerated to have a desired high energy. An insulator (not shown) is inserted between the adjacent extraction electrodes 2.

[0004] The accelerated negative ions enter the neutralization cell 3. In the neutralization cell 3, there is plasma generated by electric discharge, and the incident negative ions collide with ions and electrons in the plasma and are converted into high-speed neutral particles (D ⁰ ). The converted neutral particles become a neutral particle beam 7, travel straight through a drift tube 8 connected to the neutralization cell 3, enter a plasma such as a tokamak, and are used for heating the plasma.

On the other hand, the negative ions D ⁻ not neutralized when passing through the plasma and the positive ions D ⁺ generated by ionizing the neutralized D ⁰ are supplied to the neutralization cell 3. After passing through, the light is deflected by the magnetic field, absorbed by the beam dumps 5 and 6, and heat is removed.

The D ₂ gas introduced into the neutralization cell 3 is supplied from a supply port 4 and exhausted by exhaust pumps 9 and 10. In some cases, a high frequency is used to generate plasma in the neutralization cell 3. In a discharge using a high frequency, a magnetic field may be used in order to facilitate the generation of the discharge. In particular, it is often used for generating plasma.
In the case of a microwave having a frequency of 45 [GHz], there is a phenomenon called electron cyclotron resonance when the magnetic field intensity is 0.0875 [T], and the power of the microwave is efficiently absorbed by the plasma. Sectional view of the neutralization cell shown in Fig. 7 (JRTrow and KGMoses: CHARACT
ERISTICS OF AN RF PLASMA NEUTRALIZER: American Ins
The titute of Physics 1987 p651) discloses an example in which adjacent permanent magnets 21 are mounted on the outer wall 20 of the neutralization cell 3 so that their polarities are different from each other, and generate a magnetic field. Note that the solid line in FIG. 7 indicates the line of magnetic force.

[0007]

However, in the neutral particle injector having the above-described structure, the magnetic field does not penetrate into the interior (center) of the neutralization cell, and a desired discharge state is obtained. It was difficult to generate the required magnetic field.

When the intensity of the magnetic field is changed, it is necessary to change the number, shape, and location of the permanent magnet each time. Further, when a permanent magnet is used, there is a problem that the strength of the magnetic field is insufficient and a desired magnetic field cannot be obtained.

As described above, in the conventional neutral particle injector, the magnetic field required for generating plasma cannot be uniformly and efficiently generated in the neutralization cell, and the intensity of the magnetic field depends on the discharge condition. It was difficult to change instantly.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and a magnetic field is applied uniformly to the center of the neutralization cell. It is an object of the present invention to provide a neutral particle injector which can be changed instantaneously.

[0011]

In order to achieve the above object, a neutral particle injector according to the present invention comprises a discharge chamber for generating ions by discharge, and a high-frequency discharge for discharging ions from the discharge chamber. And a neutralization cell that collides with the plasma particles to be converted into neutral particles, provided around the neutralization cell, and is orthogonal to the traveling direction of the neutral particles passing through the neutralization cell. Magnetic field generating means for generating a magnetic field such that the intensity of a magnetic field distributed in a plane is uniform, discharge gas supply / exhaust means for supplying and exhausting a discharge gas into the neutralization cell, and the neutralization cell And a transmission unit for guiding the neutral particles generated in the above to the outside of the neutralization cell.

Next, the neutral particle injector of the present invention is distributed in a discharge chamber for generating ions by discharge and in a plane perpendicular to the traveling direction of the ions ejected from the discharge chamber. A neutralization cell that generates a magnetic field such that the intensity of the magnetic field becomes uniform and collides ions ejected from the discharge chamber with plasma particles by high-frequency discharge to convert the ions into neutral particles; It comprises discharge gas supply / exhaust means for supplying and exhausting discharge gas into the cell, and transmission means for guiding neutral particles generated in the neutralization cell to the outside of the neutralization cell. Note that the intensity of the magnetic field generated in the neutralization cell is most preferably 0.0875 [T] in the case of a high frequency such as a microwave having a frequency of 2.45 [GHz].

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a first embodiment of a neutral particle injector. The tubular neutralization cell 11 includes a waveguide 12 for introducing microwaves into the neutralization cell 11.
Is connected. A microwave source for generating microwaves connected to the neutralization cell 11 via the waveguide 12 is not shown. The neutralization cell 11 includes a neutralization cell 11.
An introduction port (not shown) for introducing a discharge gas therein is provided. Further, a solenoid coil 13 (magnetic field generating means) is wound along the outer wall of the neutralization cell 11. Here, the interval between adjacent solenoid coils is set to δ. The solenoid coil 13 includes a solenoid coil 13.
Is connected to a power supply 14 for supplying a voltage.

The operation of the first embodiment of the neutral particle injector having such a configuration will be described. Discharge gas (for example, deuterium D) introduced into the neutralization cell 11 from the introduction port
_{In 2} ), a discharge is caused by an electric field of a microwave guided from the waveguide 12 into the neutralization cell 11. The supply and exhaust of the discharge gas into the neutralization cell are performed by a discharge gas supply and exhaust unit (not shown). The discharge gas D ₂ generates plasma (D ⁺ , D ⁻ , D ⁰ ) by microwave discharge. Further, an ion beam (D ⁻ ) is incident on the neutralization cell 11 from one end of the neutralization cell 11 (in the direction of the arrow in FIG. 1). This ion beam is emitted from a discharge chamber (not shown) that generates ions by discharging. The incident negative ions D ⁻ collide with ions and electrons in the plasma and are converted into neutral particles (D ⁰ ). The neutralized beam is emitted from the other end of the neutralization cell 11 to the outside of the neutralization cell 11. The emitted neutral particle beam passes through the drift tube 16 (transmission means) and is incident on plasma such as tokamak.

Here, in order to improve the discharge efficiency in the neutralization cell 11 and uniformly distribute the plasma particles generated by the discharge in the neutralization cell 11, for example, the winding is performed around the neutralization cell 11. By supplying a predetermined current from the power supply 14 to the solenoid coil 13 without changing the number of turns of the mounted solenoid coil 13 or the shape of the neutralization cell 11,
A uniform magnetic field having a desired strength is generated in a plane orthogonal to the traveling direction of the neutral particles in the neutralization cell 11. The magnetic field generated in this way penetrates into the neutralization cell 11 (central part), and the magnetic field in the neutralization cell 11 is substantially uniform.

By changing the current supplied to the solenoid coil 13, the strength of the magnetic field can be easily changed. Furthermore, a desired magnetic field can be obtained by changing the number of turns of the solenoid coil 13 and the shape of the neutralization cell 11.

In particular, in the case of a microwave having a frequency of 2.45 [GHz], electron cyclotron resonance occurs when the magnetic field intensity is 0.0875 [T], and the power of the microwave is efficiently absorbed by the plasma. Can be.

The magnetomotive force required to uniformly generate the magnetic field strength 0.0875 [T] in the neutralization cell 11 is as follows:
It is about 70,000 [A-turn] per [m], and it is impossible to generate the neutralized cell 11 at the center (center) by a permanent magnet. On the other hand, by using the solenoid coil 13, a substantially uniform magnetic field (0.0875 [T]) can be generated up to the center (center) of the neutralization cell 11.

As described above, in the first embodiment, a desired magnetic field can be generated up to the center of the neutralization cell 11. Further, the intensity of the generated magnetic field can be made substantially uniform inside the neutralization cell 11. Therefore, a neutral particle beam can be efficiently obtained from negative ions, and a high-power neutral particle beam can be emitted.

Further, the magnetic field can be easily changed by changing the value of the current flowing through the solenoid coil 13. Also, the strength of the magnetic field can be changed by adjusting the number of turns of the solenoid coil 13 with respect to the neutralization cell 11. In addition, it is only necessary to wind the solenoid coil 13 around the neutralization cell 11, and there is no need to create a neutral particle injector by a special process, so that a significant increase in cost can be suppressed.

Next, the configuration of a second embodiment of the neutral particle injector will be described with reference to FIG. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

The feature of the second embodiment is that the neutralization cell 11 is formed of a conductor, and by connecting electrodes, the magnetic field generated inside the neutralization cell 11 can be made uniform to a desired intensity. .

FIG. 2 is a perspective view of a second embodiment of the neutral particle injector. For example, the neutralization cell 11 made of a conductor such as copper is formed with a gap in a part of the side surface. Although not shown, for example, an insulator such as alumina ceramics is inserted into the gap. The power supply 14 sandwiches the insulator.
Are connected to the neutralization cell 11. Hereinafter, the operation of the second embodiment having such a configuration will be described.

The discharge gas (for example, deuterium D ² ) introduced into the neutralization cell 11 from the inlet causes discharge by a microwave electric field guided from the waveguide 12 into the neutralization cell 11. The supply and exhaust of the discharge gas into the neutralization cell
This is performed by a discharge gas supply / exhaust unit not shown. The discharge gas D ₂ generates plasma (D ⁺ , D ⁻ , D ⁰ ) by microwave discharge. In addition, neutralization cell 1
An ion beam (D ⁻ ) is incident on the neutralization cell 11 from one end (in the direction of the arrow in FIG. 2) of the first cell 1. This ion beam is emitted from a discharge chamber (not shown) that generates ions by discharging. Incident negative ions D ^- collide with ions and electrons in the plasma is neutralized (D ^0). The neutralized neutral particle beam is emitted from the other end of the neutralization cell 11 to the outside of the neutralization cell 11. The emitted neutral particle beam passes through the drift tube 16 and enters a plasma such as a tokamak.

Here, the discharge efficiency in the neutralization cell 11 is improved, and the plasma particles generated by the discharge are generated in a plane orthogonal to the traveling direction of the ion beam incident on the neutralization cell 11. In order to distribute a magnetic field of uniform intensity
For example, by supplying a predetermined current from the power supply 14 to the neutralization cell 11 made of a conductive material without changing the shape of the neutralization cell 11, a magnetic field of a desired intensity is generated in the neutralization cell 11. Let me. The magnetic field generated in this way penetrates into the inside (central part) of the neutralization cell 11, and the magnetic field in the neutralization cell 11 becomes substantially uniform. Also, by changing the current of the power supply 14, the strength of the magnetic field can be easily changed. Further, a desired magnetic field can be easily obtained by changing the shape of the neutralization cell 11.

In particular, in the case of a microwave having a frequency of 2.45 [GHz], electron cyclotron resonance occurs when the magnetic field intensity is 0.0875 [T], and the power of the microwave is efficiently absorbed by the plasma. Can be.

The magnetomotive force necessary to uniformly generate the magnetic field strength 0.0875 [T] in the neutralization cell 11 is as follows:
It is about 70,000 [A-turn] per [m], and it is impossible to generate the neutralized cell 11 at the center (center) by a permanent magnet. However, the neutralization cell 11
The neutralization cell 11 is generated by applying a voltage to the
An almost uniform magnetic field (0.0875) up to the center (center)
[T]) can be generated.

As described above, according to the present invention as described in the second embodiment, a desired uniform magnetic field can be generated up to the central portion of the neutralization cell 11. Further, the intensity of the generated magnetic field can be made substantially uniform within the neutralization cell 11. Therefore, a neutral particle beam can be efficiently obtained from negative ions, and a high-power neutral particle beam can be emitted.

Further, the magnetic field can be easily changed by changing the value of the current supplied from the power supply 14. Further, it is only necessary to provide a gap in a part of the neutralization cell 11 and insert an insulator into the gap, and it is not necessary to create a neutral particle injection device by a special process, which leads to a significant increase in cost. Can be suppressed. Further, when the neutralization cell 11 is formed of copper, the heat conductivity is good, and when the neutralization cell 11 is formed of SUS, high strength can be obtained.

Next, the configuration of a third embodiment of the neutral particle injector will be described with reference to FIG. The feature of the third embodiment is that the magnetic field shield 17 is arranged around the neutralization cell 11 around which the solenoid coil 13 is wound, which is the same as the embodiment shown in the first embodiment. This is to prevent the magnetic field from leaking out.

FIG. 3 is a sectional view of a third embodiment of the neutral particle injector. Magnetic field shielding portions 17 (magnetic field shielding means) made of a material having a high magnetic permeability are arranged at predetermined intervals around the neutralization cell 11 around which the solenoid coil 13 is wound. The magnetic field shield 17 is made of, for example, iron or mu metal, and efficiently shields a magnetic field generated from the solenoid coil 13 due to its high magnetic permeability.

The operation of the third embodiment having such a configuration will be described. Neutralization cell 11 from inlet not shown
The discharge gas (for example, deuterium D ₂ ) introduced into the neutralization cell 11 from the waveguide 12 connected to the neutralization cell 11
Discharge is caused by the microwave electric field guided inside.
The discharge gas D ₂ generates plasma (D ⁺ , D ⁻ , D ⁰ ) by microwave discharge. Further, an ion beam (D ⁻ ) is incident on the neutralization cell 11 from one end of the neutralization cell 11 (in the direction of the arrow in FIG. 3). The incident negative ions D ⁻ collide with ions and electrons in the plasma and are converted into neutral particles (D ⁰ ). The neutralized neutral beam is
It is injected from the other end of the neutralization cell 11 to the outside of the neutralization cell 11. The emitted neutral particle beam passes through a drift tube (not shown) and enters a plasma such as a tokamak.

Here, in order to improve the discharge efficiency in the neutralization cell 11 and uniformly distribute the plasma particles generated by the discharge in the neutralization cell 11, for example, the winding is performed around the neutralization cell 11. By supplying a predetermined current from a power supply to the solenoid coil 13 without changing the number of turns of the mounted solenoid coil 13 or the shape of the neutralization cell 13, a magnetic field of a desired intensity is generated in the neutralization cell 11. Has occurred. The magnetic field generated in this way penetrates into the neutralization cell 11 (central part), and the magnetic field in the neutralization cell 11 becomes a substantially uniform magnetic field.

By changing the current supplied to the solenoid coil 13, the intensity of the magnetic field can be easily changed.
Similarly, a desired uniform magnetic field can be obtained by changing the number of turns of the solenoid coil 13 or the shape of the neutralization cell 13.

In particular, in the case of a microwave having a frequency of 2.45 [GHz], electron cyclotron resonance occurs when the magnetic field intensity is 0.0875 [T], and the output of the microwave is efficiently absorbed by the plasma. Can be.

The magnetomotive force required to uniformly generate the magnetic field strength of 0.0875 [T] in the neutralization cell 11 is as follows:
It is about 70,000 [A-turn] per [m], and it is impossible to generate the neutralized cell 11 at the center (center) by a permanent magnet. However, by using the solenoid coil 13, a substantially uniform magnetic field (0.0875) is obtained up to the center (center) of the neutralization cell 11.
[T]) can be generated.

Further, the magnetic field generated by the solenoid coil 13 is passed through the magnetic field shield 17 to prevent the magnetic field from leaking out of the neutralization cell 11. As described above, in the third embodiment, a desired uniform magnetic field can be generated up to the center of the neutralization cell 11. Also,
The intensity of the generated magnetic field can be made substantially uniform inside the neutralization cell 11. Therefore, a neutral particle beam can be efficiently obtained from negative ions, and a high-power neutral particle beam can be emitted.

Further, the magnetic field can be easily changed by changing the value of the current flowing through the solenoid coil 13. Also, the strength of the magnetic field can be changed by adjusting the number of turns of the solenoid coil 13 with respect to the neutralization cell 11. In addition, it is only necessary to wind the solenoid coil 13 around the neutralization cell 11, and there is no need to create a neutral particle injector by a special process, so that a significant increase in cost can be suppressed.

Further, under the environmental conditions of the installation place of the neutral particle injector, there is a case where it is desired to avoid the influence of the magnetic field leaking from the neutralization cell 11 to the outside. Even in such a case, the provision of the magnetic field shield 17 can greatly reduce the installation conditions.

Next, the configuration of a fourth embodiment of the neutral particle injector will be described with reference to FIG. The feature of the fourth embodiment is that the magnetic field shielding portion 17 is arranged around the neutralization cell 11 made of a conductive material, that is, the magnetic field leakage outside the neutralization cell 11. That is to prevent.

FIG. 4 is a sectional view of a fourth embodiment of the neutral particle injector. A tubular member made of a material having a high magnetic permeability is provided at a predetermined interval on the outer periphery of a neutralization cell 11 made of, for example, copper, having a gap in a part of the side surface, and an insulator such as alumina ceramics inserted in the gap. Magnetic field shield 17
(Magnetic field generating means) are arranged. The magnetic field shield 17 is made of, for example, iron or mu metal, and efficiently shields a magnetic field generated from the neutralization cell 11 due to its high magnetic permeability.

The operation of the fourth embodiment having such a configuration will be described. The discharge gas (for example, deuterium D ² ) introduced into the neutralization cell 11 made of a conductor from an inlet (not shown) flows from the waveguide connected to the neutralization cell 11 into the neutralization cell 11. Discharge is caused by the induced microwave electric field. The discharge gas D ₂ generates plasma (D ⁺ , D ⁻ , D ⁰ ) by microwave discharge. Also,
An ion beam (D ⁻ ) is incident on the neutralization cell 11 from one end of the neutralization cell 11 (the direction of the arrow in FIG. 4). The incident negative ions D ⁻ collide with ions and electrons in the plasma and are converted into neutral particles (D ⁰ ). The neutralized neutral particle beam is emitted from the other end of the neutralization cell 11 to the outside of the neutralization cell 11. The emitted neutral particle beam passes through a drift tube (not shown) and enters a plasma such as a tokamak. Here, the discharge efficiency in the neutralization cell 11 is improved, and the plasma particles generated by the discharge are uniformly distributed in a plane orthogonal to the traveling direction of the neutral particles passing through the neutralization cell 11. For distribution, for example, by supplying a predetermined current from a power source to the neutralization cell 11 without changing the shape of the neutralization cell 11, a uniform magnetic field of a desired intensity is introduced into the neutralization cell 11. Is occurring. The magnetic field generated at this time penetrates into the neutralization cell 11 (central part), and the magnetic field in the neutralization cell 11 is almost uniform.
Also, by changing the current supplied to the neutralization cell 11,
The strength of the magnetic field can be easily changed. Further, by changing the shape of the neutralization cell 11, a desired uniform magnetic field can be obtained.

Particularly, in the case of a microwave having a frequency of 2.45 [GHz], electron cyclotron resonance occurs when the magnetic field intensity is 0.0875 [T], and the output of the microwave is efficiently absorbed by the plasma. Can be.

The magnetomotive force required to uniformly generate the magnetic field strength 0.0875 [T] in the neutralization cell 11 is as follows:
It is about 70,000 [A-turn] per [m], and it is impossible to generate the neutralized cell 11 at the center (center) by a permanent magnet. However, if the neutralization coil is formed of a conductor, a substantially uniform magnetic field (0.0875 [T]) can be generated up to the center (center) of the neutralization cell 11.

The magnetic field generated in the neutralization cell 11 is
The neutralization cell 11 is passed through the magnetic field shielding unit 17.
It prevents the magnetic field from leaking out. As described above, in the fourth embodiment, a desired magnetic field can be generated up to the center of the neutralization cell 11. Further, the intensity of the generated magnetic field can be made substantially uniform inside the neutralization cell 11. Therefore, a neutral particle beam can be efficiently obtained from negative ions, and a high-power neutral particle beam can be emitted.

Further, the magnetic field can be easily changed by changing the value of the current flowing through the neutralization cell 11. Further, it is only necessary to insert an insulator into the gap at a part of the side surface of the neutralization cell 11, and it is not necessary to create a neutral particle injection device by a special process, and it is possible to suppress a significant increase in cost. . Further, when the neutralization cell 11 is formed of copper, the heat conductivity is good, and when the neutralization cell 11 is formed of SUS, high strength can be obtained.

Further, under the environmental conditions of the place where the neutral particle injector is installed, there is a case where it is desired to avoid the influence of the magnetic field leaking from the neutralization cell 11 to the outside. Even in such a case, the installation condition can be remarkably relaxed by the configuration of the magnetic field shielding unit 17.

Next, the configuration of a fifth embodiment of the neutral particle injector will be described with reference to FIG. The feature of the fifth embodiment is that cooling means 15 is provided around the neutralization cell 11 to cool the neutralization cell 11 and improve safety.

FIG. 5 is a sectional view of a fifth embodiment of the neutral particle injector. Cooling means 15 for circulating a coolant such as water inside is provided on the outer periphery of the neutralization cell 11.

The operation of the fifth embodiment having such a configuration will be described. The walls of the neutralization cell 11 are heated by the collision of the plasma particles. This heat is cooled by a coolant such as water flowing through the cooling means 15.

As described above, in the fifth embodiment, the heat generated in the neutralization cell 11 is cooled by the cooling means 15 in order to obtain desired plasma particles. Therefore, the safety during operation of the neutral particle injector can be improved, and a high-power neutral particle beam can be obtained.

The present invention is not limited to the above embodiment,
It goes without saying that various modifications can be made without departing from the spirit of the invention. For example, the cooling means may be in any form as long as it cools the heat from the solenoid coil or the neutralization cell. Further, the coolant heated by the cooling means may be sent to a power generation unit such as a gas turbine to generate electric power and used for a neutral particle injector. Further, it may be used as a heating source for heating the discharge chamber to a predetermined temperature.

[0053]

As described above, in the present invention, plasma particles can be efficiently generated by infiltrating a magnetic field having a uniform strength into the interior of the neutralization cell.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of a neutral particle injector according to the present invention.

FIG. 2 is a perspective view of a second embodiment of the neutral particle injector of the present invention.

FIG. 3 is a cross-sectional view of a third embodiment of the neutral particle injector of the present invention.

FIG. 4 is a cross-sectional view of a fourth embodiment of the neutral particle injector of the present invention.

FIG. 5 is a sectional view of a fifth embodiment of the neutral particle injector of the present invention.

FIG. 6 is a cross-sectional view of a conventional neutral particle injector.

FIG. 7 is a sectional view of a discharge vessel of a conventional neutral particle injector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Neutralization cell 12 Waveguide 13 Solenoid coil (magnetic field generating means) 14 Power supply 15 Cooling means 16 Drift tube (power transmission means) 17 Magnetic field shielding part (magnetic field shielding means)

Claims (6)

[Claims] A discharge chamber for generating ions by discharge; a neutralization cell for converting ions ejected from the discharge chamber into neutral particles by colliding with plasma particles by high-frequency discharge; Magnetic field generating means for generating a magnetic field such that the intensity of a magnetic field distributed in a plane orthogonal to the direction of travel of neutral particles passing through the neutralization cell is provided around the cell and is uniform. Discharge gas supply and exhaust means for supplying and exhausting a discharge gas into the neutralization cell, and transmission means for guiding neutral particles generated in the neutralization cell to the outside of the neutralization cell. A neutral particle injector. 2. A magnetic field in which the intensity of a magnetic field distributed in a discharge chamber for generating ions by discharge and a magnetic field distributed in a plane orthogonal to the traveling direction of ions ejected from the discharge chamber is uniform. And a neutralization cell for converting ions ejected from the discharge chamber into neutral particles by colliding with ions generated by the high-frequency discharge, and a discharge for supplying and exhausting a discharge gas into the neutralization cell. A neutral particle injector comprising: gas supply / exhaust means; and transmission means for guiding neutral particles generated in the neutralization cell to the outside of the neutralization cell. 3. The neutral particle injector according to claim 1, further comprising magnetic field shielding means for shielding a magnetic field generated from said magnetic field generating means around said neutralization cell. 4. The neutral particle injector according to claim 2, further comprising magnetic field shielding means for shielding a magnetic field generated from said neutralization cell around said neutralization cell. 5. A neutral particle injector according to claim 1, wherein said neutralizing cell is provided with a cooling means for cooling heat generated when plasma particles are generated. 6. The magnetic field generating means according to claim 1, wherein the magnetic field generating means is a solenoid coil wound along the outer wall of the neutralization cell and generating a desired uniform magnetic field up to the neutralization cell center. 1. The neutral particle injector according to 1.