JPH10132976A - Control device of neutral particle incident device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently make a beam incident on an incident target of beam by regulating the power source voltage of an auxiliary power source according to the change of power source voltage of a main power source connected between accelerating electrodes. SOLUTION: A plasma electrode 29, a drawing electrode 30, and an earthed electrode 31 are set within the ion generating chamber of negative ion source of a neutral particle incident device. The electrodes 29, 31 are connected to a main power source 44 for generating the highest accelerating voltage, and the electrodes 30, 31 are connected to an auxiliary power source 46 having a low power source voltage. When the voltage of the main power source 44 is changed by the change of a target value of incident quantity of neutral particle, the thermal load distribution of ion beam within a vacuum chamber is measured. While monitoring the measured value, the power source voltage of the auxiliary power source 46 is regulated according to the change of power source voltage of the main power source 44. Therefore, even if the voltage of the main power source 44, the beam can be converged to a designated focal point of an incident port, and efficiently incident on a fusion device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a neutral particle injector and a control method thereof, and more particularly to a neutral device suitable for injecting neutral particles generated from negative ions into a thermonuclear fusion device. The present invention relates to a control device and a control method for a particle incident device.

[0002]

2. Description of the Related Art Conventionally, as a neutral particle injector for injecting neutral particles into a thermonuclear fusion apparatus, two or more ion sources are conventionally provided for one beam line, and each ion source is arranged vertically. And a method of arranging each ion source in the left and right (horizontal direction). An example of the adoption of the former method is “design study of negative ion NBI device for JT-60U” (March 1994, Japan Atomic Energy Research Institute, LAERI-M-94-072, p. 118).
Some are described in On the other hand, as a method adopting the latter method, for example, the size of the ion source is set to 30c.
m (diameter), and in this case, the beam thermal load at the entrance port of the fusion device can be reduced. However, in order to converge a plurality of beams, it is necessary to make the electrodes of each ion source spherical. Further, the size of the ion source is increased, and several tens cm × 100 cm or more (rectangular) or 100
When using an ion source of about 200 cm (circular) or using a negative ion source of 5 MW to 10 MW per unit, the size of the electrode of each ion source also increases, and each electrode is processed into a spherical shape. However, it is difficult to process high-precision ones. Therefore, an attempt has been made to slightly shift the position of the beamlet hole of a specific electrode among the electrodes of the ion source between the electrodes, and to converge the beam by a lens effect due to the displacement of the beamlet hole.

[0003]

In the prior art, when arranging a plurality of ion sources on the left and right, the beam is converged by utilizing a lens effect due to displacement of a beamlet hole of an acceleration electrode. In some cases, the beam does not converge to a fixed focal position, and the beam size increases in a portion inside the entrance port, so that the beam incidence efficiency deteriorates and a heat load inside the entrance port becomes a problem. That is, when an ion source that generates negative ions is used as the ion source, a magnetic filter as a magnetic field for moving only low-speed electrons is provided in the ion generation chamber of the ion source.
In order to suppress the movement of electrons, there is a magnetic field formed in the beamlet in the extraction electrode. Therefore, even when converging the beam, it is necessary to consider simultaneously the deflection of the ion beam due to the influence of the magnetic field and the deflection due to the displacement of the beamlet hole. In addition, the amount of displacement due to deflection differs depending on the beam acceleration voltage. Therefore, even when the beam is converged by the lens effect due to the displacement of the beamlet hole, it is necessary to adjust not only the beam acceleration voltage but also the beam acceleration voltage in consideration of both the beam convergence effect and the displacement due to the magnetic field. is there.

An object of the present invention is to provide a control device and a control method of a neutral particle injector capable of efficiently making a beam incident on a beam incidence target.

[0005]

In order to achieve the above object, the present invention provides an ion beam system in which a plurality of accelerating electrodes having beam holes are connected to a plurality of power sources, respectively, to accelerate ions existing between the accelerating electrodes. And a vacuum vessel having a beam transmission path that converts an ion beam from the ion source into a beam of neutral particles and guides the beam to an incident port of an incident target. A heat load distribution measuring means for measuring the heat load distribution of the ion beam in the container, and a main power supply connected between the accelerating electrodes for generating the highest accelerating voltage among the accelerating electrodes based on the measured values of the heat load distribution measuring means Power source voltage adjusting means for adjusting the power source voltage of the auxiliary power source connected between the accelerating electrodes whose beam holes are displaced from each other in accordance with the change of the power source voltage of the neutral particles. It is obtained by configuring the control device morphism device.

According to the present invention, as a control device, a plurality of accelerating electrodes each having a beam hole are connected to a plurality of power sources, respectively, and a plurality of ion sources for accelerating ions existing between the accelerating electrodes to generate an ion beam are provided. A vacuum vessel having a plurality of beam transmission paths that convert an ion beam from each ion source into a beam of neutral particles and guide each beam to an incident port of an incident target. Heat load distribution measuring means for measuring the heat load distribution of the ion beam, and a power supply of a main power supply connected between the accelerating electrodes generating the highest accelerating voltage among the accelerating electrodes based on the measured values of the heat load distribution measuring means Power supply voltage adjusting means for adjusting a power supply voltage of an auxiliary power supply connected between accelerating electrodes whose beam holes are displaced from each other in accordance with a change in voltage; It is obtained by configuring the control device of the entrance device.

In configuring the control device, the following elements can be loaded.

(1) The heat load distribution measuring means includes a heat receiving portion which is inserted into the beam transmission path and receives a beam, and the heat receiving portion gradually approaches both sides of the axis of the beam transmission path toward the ion source. It has a plurality of inclined surfaces, and each inclined surface is formed from the axis of the beam transmission path to the side wall.

(2) The heat load distribution measuring means includes a plurality of heat receiving sections inserted into each beam transmission path to receive the beam.
Each heat receiving portion has a plurality of inclined surfaces on both sides gradually approaching the ion source side around the axis of each beam transmission path, each inclined surface is formed from the axis of each beam transmission path to the side wall, and Ends of adjacent inclined surfaces among the inclined surfaces of the heat receiving portion are connected to each other.

According to the present invention, as a control method, a plurality of accelerating electrodes having beam holes are connected to a plurality of power sources, respectively, and a plurality of ion sources for accelerating ions existing between the accelerating electrodes to generate an ion beam are provided. When operating a neutral particle injector comprising a vacuum vessel having a plurality of beam transmission paths each of which converts an ion beam from each ion source into a beam of neutral particles and guides the ion beam to an incident port of an incident object, Measure the heat load distribution of the ion beam in the vacuum vessel, based on this measured value, according to the change in the power supply voltage of the main power supply connected between the accelerating electrodes that generate the highest accelerating voltage among the accelerating electrodes, A method for controlling a neutral beam injector is characterized in that a power supply voltage of an auxiliary power supply connected between accelerating electrodes whose beam holes are displaced from each other is adjusted.

When employing the above control method, the generation of the ion beam can be stopped when the measured value of the thermal load distribution due to the deflection of the potential voltage does not fall within the range of the set value.

According to the above-mentioned means, when the voltage of the main power supply connected between the electrodes generating the highest accelerating voltage is changed due to the change of the target value of the incident amount of the neutral particles, the ion in the vacuum vessel is changed. By measuring the heat load distribution of the beam and monitoring this measurement value, the power supply voltage of the auxiliary power supply is adjusted according to the change in the power supply voltage of the main power supply. Can be converged to a designated focal position at the entrance port.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a neutral particle injector showing one embodiment of the present invention. In FIG. 1, a neutral particle injector (NBI: Neutral Beam Inj)
The electron fusion device 12 is provided for heating a plasma or driving a current in the plasma in the fusion device 12, and includes two negative ion sources 14 and 16, angle adjustment mechanisms 18 and 20, a vacuum vessel. 21 and 22, an ion source chamber 23, a neutralization cell 24, and a beam dump chamber 25. The vacuum chambers 21 and 22 are housed in the ion source chamber 23 and the beam dump chamber 25, respectively. The side is inserted into the entrance port 26 of the fusion device (main body) 12. The negative ion sources 14 and 16 are arranged apart from each other in the left-right (horizontal) direction. In the ion generation chamber 27 of each of the negative ion sources 14 and 16, as shown in FIG. 29, extraction electrode 30, ground electrode 31
Is installed. The magnetic filter 28 is configured to move only low-speed electrons. Each electrode 29, 3
0 and 31 are formed in a substantially flat plate shape.
30 and 31 have beamlet holes 34, 36 and 3 respectively.
8 are formed. In these beamlet holes, a magnetic field for preventing acceleration of electrons when negative ions are accelerated is formed in the beamlet hole 36 of the extraction electrode 30. Further, as shown in FIG.
Numeral 36 is formed at the same position with respect to the centers of the electrodes 29 and 30, and beamlet holes 36 and 38 are formed at positions offset from each other with respect to the centers of the electrodes 30 and 31. That is, the beamlet holes 36 and 38 are formed at positions displaced from each other by the displacement amount (displacement amount) d. For this reason, the ion beam 40 output from the beamlet hole 38 is deflected at an angle displaced from the reference line 42 passing through the centers of the beamlet holes 34 and 36 by the deflection angle θ. The displacement d of the beamlet holes 36 and 38 formed in the electrodes 30 and 32 is
31 are set so as to be shifted in opposite directions on both sides with reference to the center of 31. As a result, the ion beam 40 output from each beamlet hole 38 of the electrode 31 converges to the designated focal positions 41 and 43. And electrodes 29, 31
Are connected to a main power supply 44 that generates the maximum acceleration voltage, and the electrodes 30 and 31 are connected to an auxiliary power supply 46 having a lower power supply voltage than the main power supply 44. Main power supply 44, auxiliary power supply 4
Numerals 6 are connected to a power supply voltage regulator (not shown) as power supply voltage adjusting means, and the power supply voltages of the main power supply 44 and the auxiliary power supply 46 are adjusted by operating each power supply voltage regulator. Has become.

The ion beams 40 generated from the negative ion sources 14 and 16 are roughly adjusted by angle adjusting mechanisms 18 and 20 and then introduced into vacuum vessels 21 and 22. The vacuum vessels 21 and 22 respectively transmit the ion beams 40 generated from the negative ion sources 14 and 16 to the entrance port 2 of the fusion device 12.
6 is formed as a container forming an ion beam transmission path leading to 6, and the distal ends of the vacuum containers 21 and 22 intersect to form an integral structure. And, each vacuum vessel 21, 2
In the ion beam 40 transmitting the ion beam 2, negative ions (hydrogen) are neutralized by the neutralization cell 24 and are incident on the entrance port 26.

The vacuum container 2 in the beam dump chamber 25
As shown in FIGS. 4 and 5, a calorie meter 48 as a heat load distribution measuring means for measuring a heat load distribution of the ion beam is inserted into each of the first and the second 22.
The calorie meter 48 includes a plurality of heat receiving units 50 and 52, and only when measuring a heat load distribution,
22 is inserted. The calorimeter 48 has heat receiving portions 50 and 52 integrally formed, and has a substantially W-shaped plane. Heat receiving part 50
Has inclined surfaces 54 and 56, and the heat receiving portion 52 has an inclined surface 58,
The inclined surface 54 and the end of the inclined surface 60 are connected to each other. The inclined surfaces 54 and 56 are
Are formed in a tapered shape such that both sides thereof gradually approach the negative ion source 14 with the axis 62 as the center.
Numeral 60 is formed in a tapered shape in which both sides thereof gradually approach the negative ion source 16 with an axis 64 of the vacuum vessel 22 as a center. That is, since the inclined surfaces 54, 56, 58, and 60 are arranged over the entire area where the beam exists and are inclined with respect to the axes 62 and 62, the heat receiving portions 50 and 52 are formed in a flat plate shape. The amount of heat received per unit area can be made smaller than that of the one. That is, the heat resistance against the heat load can be increased.

In the neutral particle injector 10 having the above-described configuration, when the ion beam 40 generated from the negative ion sources 14 and 16 is converted into neutral particles and is incident on the incident port 26, calories are stored in the vacuum vessels 21 and 22. The meter 48 is inserted, and the heat load distribution based on the output of the calorie meter 48 is output as a profile as shown in FIG. At this time, when the temperature of the plasma in the fusion device 12 is, for example, 2000 ° C., the power supply voltage of the main power supply 44 is adjusted in accordance with the target temperature. At this time, the power supply voltage of the auxiliary power supply 46 is adjusted so that the beams transmitted from the ion sources 14 and 16 converge on the focal positions 41 and 43, respectively. That is, the deflection angle θ of the ion beam generated from the negative ion sources 14 and 16 is
6, the shift amount of 38 is d, the electric field between the electrodes 30 and 31 is E,
When the power supply voltage of the main power supply 44 is V, the power supply voltage of the auxiliary power supply 46 is Vp, and the distance between the electrodes 30 and 31 is p, the deflection angle θ is proportional to d · E / V. Where E = Vp / p
It is. For this reason, when changing the electric field E in accordance with the change in the voltage V, the voltage Vp is adjusted in accordance with the change in the voltage V. And the voltage V of the auxiliary power supply 46
When adjusting p, as shown in FIG. 6, the measured value of the calorimeter 48 is 1 / e (e indicates electron volt).
Is adjusted so as to fall within the range of the beam distribution width (set value) or less. When the voltage Vp is adjusted so that the center of the profile measured by the calorimeter 48 coincides with the central axis, the beams transmitted through the vacuum vessels 21 and 22 are focused on the focal positions 41 and 43.
Converges to

When the voltage Vp is adjusted, the profile measured by the calorimeter 48 may change over a wide range due to the change in the voltage Vp. Even in such a case, the heat receiving section 50 of the calorimeter 48 may be used.
Since 52 is formed over the entire area where the beam exists (moves), the thermal load distribution of the ion beam can be easily measured.

According to the present embodiment, the power supply voltage Vp is adjusted according to the change of the power supply voltage V, so that the beam can be efficiently incident on the fusion device 12.

Since the beam is efficiently incident on the fusion device 12, abnormal heat incidence can be prevented, and the reliability of the fusion device 12 and the neutral particle injector 10 can be improved. . Further, it is not necessary to perform an excessive thermal design for the thermal load on the inner wall of the entrance port 26.

[0021]

As described above, according to the present invention,
Since the power supply voltage of the auxiliary power supply is adjusted according to the change in the power supply voltage of the main power supply, the beam can be efficiently incident on the beam incidence target.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a neutral particle injector showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of an ion generation chamber.

FIG. 3 is a diagram illustrating a configuration of an electrode.

FIG. 4 is an enlarged view of a main part of the apparatus shown in FIG.

FIG. 5 is an enlarged view of a calorimeter.

FIG. 6 is a characteristic diagram showing a profile of a calorimeter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Neutral particle injection device 12 Nuclear fusion device 14, 16 Negative ion source 21, 22 Vacuum container 23 Ion source room 24 Neutralization cell 25 Beam dump room 26 Injection port 48 Calorimeter 50, 52 Heat receiving unit 54, 56, 58 , 60 slope

Claims (6)

[Claims] A plurality of accelerating electrodes each having a beam hole are connected to a plurality of power sources, respectively, for accelerating ions existing between the accelerating electrodes to generate an ion beam, and for neutralizing an ion beam from the ion source. A vacuum container having a beam transmission path that converts the beam into a beam of particles and guides the beam to an incident port of an incident target; and a heat load distribution measurement for measuring a heat load distribution of the ion beam in the vacuum container. Means, the beam holes are displaced from each other in accordance with a change in the power supply voltage of the main power supply connected between the accelerating electrodes that generate the highest accelerating voltage among the accelerating electrodes based on the measurement value of the heat load distribution measuring means. A control device for a neutral particle injector, comprising: a power supply voltage adjusting means for adjusting a power supply voltage of an auxiliary power supply connected between the arranged acceleration electrodes. 2. A plurality of accelerating electrodes each having a beam hole are connected to a plurality of power sources, respectively, and a plurality of ion sources for accelerating ions existing between the accelerating electrodes to generate an ion beam;
A vacuum container having a plurality of beam transmission paths each of which converts an ion beam from each ion source into a beam of neutral particles and guides the beam to an incident port of an incident object, in a neutral particle incident device, A heat load distribution measuring means for measuring a heat load distribution of the ion beam; and a power supply voltage of a main power supply connected between the accelerating electrodes which generate the highest accelerating voltage among the accelerating electrodes based on a measured value of the heat load distribution measuring means. And a power supply voltage adjusting means for adjusting a power supply voltage of an auxiliary power supply connected between the accelerating electrodes whose beam holes are displaced from each other in accordance with the change in the power supply voltage. 3. The heat load distribution measuring means includes a heat receiving portion which is inserted into the beam transmission path and receives a beam. The heat receiving portion includes a plurality of heat receiving portions whose both sides gradually approach the ion source with respect to the axis of the beam transmission path. 3. The control device for a neutral particle injector according to claim 1, wherein the inclined surfaces are formed from the axis of the beam transmission path to the side wall. 4. The thermal load distribution measuring means includes a plurality of heat receiving sections inserted into each beam transmission path to receive a beam, and each heat receiving section has an ion source side on both sides around the axis of each beam transmission path. A plurality of inclined surfaces gradually approaching to each other, each inclined surface is formed from the axis of each beam transmission path to the side wall, and ends of adjacent inclined surfaces among the inclined surfaces of each heat receiving portion are connected to each other. The control device for a neutral particle injector according to claim 2, wherein 5. A plurality of ion sources each having a plurality of accelerating electrodes having beam holes connected to a plurality of power sources and accelerating ions existing between the accelerating electrodes to generate an ion beam;
When operating a neutral particle injector including a vacuum vessel having a plurality of beam transmission paths that convert an ion beam from each ion source into a beam of neutral particles and guide them to an incident port of an incident target, The heat load distribution of the ion beam in the container is measured, and based on the measured value, the beam is adjusted according to the change in the power supply voltage of the main power supply connected between the accelerating electrodes that generate the highest accelerating voltage among the accelerating electrodes. A method for controlling a neutral particle injector, comprising: adjusting a power supply voltage of an auxiliary power supply connected between acceleration electrodes whose holes are displaced from each other. 6. A control method for a neutral particle injector, wherein generation of an ion beam is stopped when a measured value of a heat load distribution accompanying a change in a power supply voltage does not fall within a set value range.