Ion beam forming apparatus for heating, nuclear fusion apparatus, plasma generation apparatus, and heating method

Abstract

This invention provides a new technology that can effectively heat plasma or plasma generating gases. [Solution] The heating ion beam forming apparatus 30 includes a magnetic field generator 31 that generates a magnetic field in the passage region R of the ion beam traveling to the target region T where the plasma 1 or plasma generating gas exists, and an electric field generator 32 that generates an electric field in the passage region R. The magnetic field generated by the magnetic field generator 31 and the electric field generated by the electric field generator 32 cause each ion of the ion beam incident on the target region T to swirl, and the plasma 1 or plasma generating gas is heated by collisions between the swirling ions and the particles of the plasma 1 or plasma generating gas.

Description

[Technical Field]

[0001] This invention relates to a technique for generating plasma by heating a plasma generation gas. Furthermore, this invention relates to a technique for heating plasma. For example, this invention relates to a technique for inducing nuclear fusion between reactive particles in a plasma by heating the plasma. [Background technology]

[0002] Nuclear fusion is a reaction in which light atomic nuclei, such as hydrogen (hereinafter also simply called reactive particles), fuse together in a high-temperature plasma state, resulting in the formation of heavier atomic nuclei, such as helium.

[0003] Nuclear fusion includes, for example, the DT reaction, D 3 He reaction, p 11 There are reactions such as the B reaction and the DD reaction. The DT reaction is a reaction in which deuterium (D) and tritium (T), which are isotopes of hydrogen, fuse together, and this reaction produces helium-4( 4 He (helium nucleus) and a neutron are produced. 3 The He reaction involves deuterium (D) and helium-3( 3 This is a reaction in which He(s) fuses, and this reaction produces a proton and helium-4. 11 Reaction B involves light hydrogen (p) and boron-11( 11 B) is a fusion reaction in which helium-4 is produced. The DD reaction is a fusion reaction in which deuterium (D) and deuterium (D) are fused, and in this reaction, helium-3 and a neutron are produced, or tritium (T) and a proton are produced. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Takafumi Hara et al, “DEVELOPMENT OF AN ELECTRON TESTBENCH FOR PROTON CARA”, Proceedings of the 18th Annual Meeting of Particle Accelerator Society of Japan, August 9 to 12, 2021, QST-Takasaki Online, Japan, pages 653 to 655 [Non-Patent Document 2] Dr. John B. Greenly, “Ion Rings for Magnetic Fusion”, [online], OSTI.GOV Technical Report, [Retrieved October 4, 2020], Internet (URL: https: / / www.osti.gov / servlets / purl / 862052) [Non-Patent Document 3] Kashiwagi et al, “Development of a DEMO Class Neutral Beam Injection System”, Journal of Plasma and Fusion Research, Vol.99, No.3 (2023) pages 66-71, The Japan Society of Plasma Science and Nuclear Fusion Research [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The reaction cross-section (reaction probability) of nuclear fusion changes depending on the relative kinetic energy of the reacting particles in the plasma. The reaction cross-section tends to increase as the relative kinetic energy of the reacting particles increases, up to the point where it reaches its peak.

[0006] Depending on the type of reaction particles to be fused, a higher relative kinetic energy between the reaction particles is required. In one example, to obtain the peak reaction cross-section, the relative kinetic energy between the reaction particles is required to be, for example, 60 - 70 keV in the DT reaction, and D 3 in the 3He reaction, for example, 200 - 300 keV is required, and P 11 in the 11B reaction, for example, 500 - 600 keV is required, and in the DD reaction, about 1000 keV (1 MeV) is required.

[0007] Thus, in order for the reaction particles to obtain a high relative kinetic energy so that nuclear fusion occurs in the plasma, it is desirable to be able to effectively heat the plasma. Or, for other purposes, it is desirable to be able to effectively heat the plasma.

[0008] Also, when heating the plasma generation gas to make the plasma generation gas into a plasma state, it is desirable to be able to effectively heat the plasma generation gas.

[0009] Therefore, an object according to one aspect of the present invention is to provide a new technique capable of effectively heating a plasma or a plasma generation gas.

Means for Solving the Problems

[0010] An ion beam forming device for heating according to one aspect of the present invention is a magnetic field generating device that generates a magnetic field in a passage region of an ion beam that travels to a target region where a plasma or a plasma generation gas exists, and [[ID=I26]] an electric field generating device that generates an electric field in the passage region, and is provided with by the magnetic field and the electric field, each ion of the ion beam incident on the target region is swirled, and the plasma or the plasma generation gas is heated by the collision between the swirled ion and the particles of the plasma or the plasma generation gas.

[0011] A nuclear fusion device according to one aspect of the present invention is The above-described ion beam forming apparatus for heating, a confinement device that confines the plasma, or the plasma generated by heating the plasma generation gas, in the target region by a magnetic field, In the target region, the plasma is heated by causing the revolving ions to collide with the particles of the plasma, thereby causing nuclear fusion.

[0012] A plasma generation device according to an aspect of the present invention, the above-described ion beam forming apparatus for heating, a confinement device that confines the plasma generated by heating the plasma generation gas in the target region by a magnetic field, In the target region, the plasma generation gas is heated to a plasma state by causing the revolving ions to collide with the particles of the plasma generation gas. <0​​​​​​​​​​​​​​​​​​​​​​​​​​​​​The section III-III in Figure 2 shows only a pair of electrodes and a cavity container. [Figure 3B] Figure 3A shows a state where an electric field is generated in the opposite direction to that in Figure 3A. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described based on the drawings. Common parts in each figure are denoted by the same reference numerals, and redundant explanations are omitted.

[0017] [First Embodiment] Figure 1 is a schematic diagram showing the configuration of a nuclear fusion device 10 according to a first embodiment of the present invention. The nuclear fusion device 10 is a device for causing nuclear fusion between reaction particles in a plasma 1 (Figure 1) present in a target region T (the region enclosed by the dashed line indicated by the symbol T). The plasma 1 for causing nuclear fusion may mean a plasma 1 that contains one or both of two reaction particles (atomic nuclei) that fuse with each other. That is, the ions constituting the plasma 1 contain one or both of two reaction particles (atomic nuclei) that fuse with each other. If the plasma 1 contains only one of the two reaction particles (atomic nuclei) that fuse with each other, the other of those two reaction particles may be included in the ion beam described later.

[0018] (Configuration of a nuclear fusion device) As shown in Figure 1, the fusion device 10 includes a confinement device 20 and a heating ion beam forming device 30. The confinement device 20 is a device for confining the plasma 1 to the target region T.

[0019] The heating ion beam forming apparatus 30 generates a magnetic field and an electric field (for example, an oscillating electric field described later) in the passage region R of the ion beam traveling (for example, in a straight line) toward the target region T, thereby causing each ion in the ion beam to swirl. As a result, an ion beam is formed in which each ion swirls as it travels toward the target region T. That is, the heating ion beam forming apparatus 30 swirls each ion in the ion beam traveling toward the target region T around an axis along the direction of travel D of the ion beam. Here, the direction of travel D may be the direction in which the ion beam from the ion beam source 40 described later enters the passage region R (for example, while traveling in a straight line). Each ion that has been swirled by the heating ion beam forming apparatus 30 will be simply referred to as a swirling ion below.

[0020] In the first embodiment, within the passage region R, each ion of the ion beam directed to the target region T is rotated by the heating ion beam forming apparatus 30 as described above, while maintaining (for example, a constant) the velocity component in the direction of travel D. Therefore, each ion flies toward the target region T while tracing a spiral (for example, the spiral trajectory IT in Figure 1). In this way, each rotating ion is incident upon the target region T while rotating.

[0021] When swirling ions incident on the target region T collide with particles of plasma 1 in the target region T, plasma 1 is heated. Alternatively, when swirling ions incident on the target region T collide with particles of the plasma-generating gas described later in the target region T, the plasma-generating gas is heated and brought to the state of plasma 1.

[0022] <Configuration of the confinement device> The confinement device 20 includes a confinement magnetic field generator 21 that generates a magnetic field (in the example in Figure 1, the magnetic field indicated by magnetic field lines M1) that confines the plasma 1 to the target region T.

[0023] In the first embodiment, the confinement magnetic field generator 21 includes a pair of coils 21a and 21b arranged coaxially and spaced apart from each other in the direction of travel D. The pair of coils 21a and 21b generate the magnetic field that confines the plasma 1 to a target region T. In this case, the target region T is the region between the centers of the pair of coils 21a and 21b in the direction of travel D, and is the region radially inward of the pair of coils 21a and 21b with respect to their central axes. The pair of coils 21a and 21b generate a magnetic field in the same direction (to the right in Figure 1) radially inward of the pair of coils 21a and 21b. Current is supplied to the pair of coils 21a and 21b in this manner.

[0024] The confinement magnetic field generator 21 may have only a pair of coils 21a and 21b, or it may include an additional coil between the pair of coils 21a and 21b in the direction of travel D. Furthermore, the confinement magnetic field generator 21 is not limited to the above configuration and may have other configurations (e.g., known configurations) as long as it can generate a magnetic field that confines the plasma 1 to the target region T.

[0025] The containment device 20 may further include a plasma container 22, a gas supply device 23, and an exhaust device 24.

[0026] The plasma container 22 has an internal space that includes a target region T for confining the plasma 1. Furthermore, an opening (not shown) may be formed on the end face of the plasma container 22 on the side of the passage region R. Through this opening, the internal space of the plasma container 22 communicates with the aforementioned passage region R in the direction of travel D. Through this opening, each of the aforementioned swirling ions flies to the target region T in the internal space of the plasma container 22. The passage region R, together with the internal space of the plasma container 22, is sealed from the outside and may be made into a vacuum.

[0027] The gas supply device 23 supplies plasma generation gas to the internal space of the plasma vessel 22. The plasma generation gas is heated as described later to form plasma 1. The plasma generation gas may be a gas containing reactive particles (one or both of two reactive particles that undergo nuclear fusion with each other). The plasma generation gas may be, for example, deuterium, tritium, light hydrogen, boron, helium-3, or a mixture of these selected gases. The gas supply device 23 may include piping 23a connected to the plasma vessel 22. The gas supply device 23 may supply the plasma generation gas into the interior of the plasma vessel 22 through this piping 23a by a gas supply source (not shown).

[0028] The exhaust device 24 creates a vacuum in the internal space of the plasma container 22 by evacuating the internal space of the plasma container 22. This makes it easier to convert the plasma generation gas into plasma 1 in a vacuum state within the internal space of the plasma container 22. The exhaust device 24 may include piping 24a connected to the plasma container 22. The exhaust device 24 creates a vacuum state in the internal space of the plasma container 22 (and the passage region R) by evacuating the internal space of the plasma container 22 through this piping 24a using a vacuum pump (not shown).

[0029] In the internal space of the plasma container 22, under the vacuum conditions described above, the swirling ions described above may collide with particles in the plasma generating gas in the target region T, thereby heating the plasma generating gas to the state of plasma 1. However, the present invention is not limited thereto, and the plasma generating gas in the internal space of the plasma container 22 may be heated to the state of plasma 1 by other means. Such other means may be, for example, a device that supplies microwaves to the plasma generating gas and heats the plasma generating gas with the microwaves, or a device that supplies a neutral particle beam without charge to the plasma generating gas and heats the plasma generating gas with the neutral particle beam, but are not limited thereto.

[0030] The heating ion beam forming apparatus 30 heats the plasma generation gas or plasma 1 by injecting the ion beam into the target region T, causing the ions of the ion beam to collide with the plasma generation gas or plasma 1 particles in the target region T.

[0031] <Configuration of a heating ion beam forming apparatus> The heating ion beam forming apparatus 30 includes a magnetic field generator 31 and an electric field generator 32 to cause each ion of the ion beam traveling into the target region T where the plasma 1 or plasma generation gas is present to swirl within the passage region R. The magnetic field generated by the magnetic field generator 31 in the passage region R and the electric field generated by the electric field generator 32 in the passage region R cause each ion of the ion beam to swirl when it is incident on the target region T. The ion beam incident from the ion beam source 40 into the passage region R may, for example, be a beam with a narrowed cross-section. Also, the central axis of the ion beam incident from the ion beam source 40 into the passage region R may coincide with the central axis of the passage region R.

[0032] In the first embodiment, the magnetic field generator 31 generates a magnetic field in the passage region R in a direction along the direction of travel D of the ion beam, and the electric field generator 32 generates an electric field (for example, an electric field pointing in the orthogonal direction) having a component in an orthogonal direction (hereinafter also simply referred to as the orthogonal direction) perpendicular to the axis (hereinafter also simply referred to as the axis) along the direction of travel D. The electric field imparts an orthogonal velocity component to each ion of the ion beam, causing each ion having the orthogonal velocity component to orbit around the axis by the Lorentz force caused by the magnetic field. The target region T (for example, the center of the target region T) may be located on the extension of the axis. The axis may be the axis of each individual ion. These axes may include an axis that coincides with the central axis of the passage region R.

[0033] In the first embodiment, the electric field generator 32 continuously generates an oscillating electric field (rotating electric field) for each ion that is swirling due to the Lorentz force, in the direction of the ion's rotation. Here, the direction of the ion's rotation changes depending on the ion's position in the direction of rotation. Therefore, the electric field generator 32 rotates the direction of the generated electric field around a rotation axis parallel to the axis. More specifically, the electric field generator 32 may rotate the direction of the generated electric field around the rotation axis at each point in time so that the direction of the generated electric field is in the direction of the ion's rotation at that time (the direction in which the ion is moving when viewed from the axial direction), and so that the direction of the electric field at each position within the range of the ion beam at that time is substantially the same. The electric field generator 32 generates the rotating electric field so that its rotation frequency matches the rotation frequency of the swirling ion. In the first embodiment, the oscillating electric field means a rotating electric field whose direction changes in this way. In one example, this rotating electric field may be substantially uniform at each point in time within the region (passage region R) through which each ion of the ion beam passes.

[0034] The heating ion beam forming apparatus 30 injects a large number of swirling ions (swirling ions) into the target region T. These swirling ions collide with the plasma 1 or plasma generating gas particles in the target region T, thereby heating the plasma 1 or plasma generating gas. Each swirling ion that enters the target region T is confined in the target region T along with the plasma 1 in a swirling state by the magnetic field generated by the confinement magnetic field generator 21 described above. As a result, an ion ring IR (a collection of swirling ions) is formed in the target region T by the large number of swirling ions.

[0035] Furthermore, the direction of the magnetic field generated by the ion ring IR is substantially opposite to the direction of the surrounding magnetic field lines M1 (see Figure 1) generated by the confinement magnetic field generator 21 inside the ion ring IR, as shown by the dashed magnetic field lines M2 in Figure 1. However, outside the radially extending ion ring IR, the direction is substantially the same as the direction of the surrounding magnetic field lines M1 generated by the confinement magnetic field generator 21.

[0036] The magnetic field generator 31 may generate a magnetic field of a constant magnitude in a constant direction along the direction of travel D (the direction of the axis) in the passing region R. The magnetic field generator 31 may be composed of, for example, a coil 31a. This coil 31a may be a solenoid coil. The coil 31a may be arranged coaxially with the pair of coils 21a and 21b described above.

[0037] The coil 31a may be a superconducting coil formed of a superconductor. This superconductor may be a high-temperature superconductor. However, this superconductor may also be a low-temperature superconductor. In this case, as shown in Figure 1, the magnetic field generator 31 has a cryostat that holds an extremely cold liquefied gas (e.g., liquefied helium) inside. The superconducting coil 31a is placed inside the cryostat 31b. The liquefied gas inside the cryostat 31b cools the superconducting coil 31a, causing it to enter a superconducting state.

[0038] The magnetic field generator 31 according to the first embodiment is not limited to the configuration described above, and may have other configurations as long as it is a device that generates a magnetic field in a direction along the propagation direction D of the ion beam.

[0039] In the first embodiment, the electric field generator 32 generates an electric field that rotates around the rotation line along the direction of travel D as an oscillating electric field. This oscillating electric field is directed in a perpendicular direction, but as described above, the direction of the oscillating electric field (i.e., the perpendicular direction) rotates around the rotation axis over time. The electric field generator 32 has a hollow container 32a and an electromagnetic wave supply device 32b.

[0040] The cavity container 32a internally partitions the cavity that serves as the passage region R described above. The cavity container 32a may be, for example, a cylindrical container that partitions a cylindrical cavity. The cavity container 32a is made of a conductive material (e.g., metal). The central axis of the cavity container 32a (passage region R) may coincide with the central axis of the coil 31a. The cavity container 32a may be arranged coaxially with the plasma container 22. In this case, the plasma container 22 may be cylindrical.

[0041] In addition, in the cavity container 32a, an opening (not shown) is formed on the end face on the ion beam source 40 side, allowing the ion beam from the ion beam source 40 to enter the passage region R, and an opening (not shown) is formed on the end face on the target region T side, allowing each swirling ion to enter the target region T.

[0042] The electromagnetic wave supply device 32b supplies electromagnetic waves to the cavity R that generate an oscillating electric field in the cavity R, which is an electric field that rotates around a rotation axis along the direction of travel D (hereinafter also simply referred to as a rotating electric field). The electromagnetic wave supply device 32b may be, for example, a microwave source that supplies microwaves as electromagnetic waves to the cavity R.

[0043] The electromagnetic wave supply device 32b may supply electromagnetic waves to the cavity through the waveguide 32c, as shown in Figure 1. The waveguide 32c guides the electromagnetic waves to the cavity R while reflecting them on its inner surface. The tip of the waveguide 32c is connected to the end face of the cavity container 32a so that its interior communicates with the cavity R. In this case, as shown in Figure 1, a partition plate 32d that transmits electromagnetic waves but not gas may be provided in the middle of the waveguide 32c. This allows the space on the cavity side including the cavity R (i.e., the region on the cavity R side of the partition plate 32d inside the waveguide 32c and the cavity R) to be maintained in a vacuum state. The ion beam from the ion beam source 40 may be incident on the vacuum portion inside the waveguide 32c, for example, through a beam window (not shown).

[0044] The rotational frequency of a rotating electric field may coincide with the rotational frequency of a swirling ion. Here, the rotational frequency is the number of times the rotating electric field rotates per unit time, and the rotational frequency is the number of times the swirling ion rotates per the same unit time. The rotational frequency f of such a rotating electric field may be expressed by the following equation.

number

[0045] The cavity container 32a may be a cavity resonator that partitions the resonant cavity as a cavity R. In this case, the electromagnetic wave supply device 32b generates a rotating electric field by supplying electromagnetic waves to the resonant cavity R in such a way that standing waves (TE111 mode standing waves) are generated in the resonant cavity R. In this case, the dimensions and shape of the cavity container 32a and waveguide 32c, the frequency of the electromagnetic waves, etc. are set so that standing waves are generated in the resonant cavity R.

[0046] The electromagnetic wave supply device 32b may supply electromagnetic waves (e.g., microwaves) from an opening (not shown) at the end face of the cavity container 32a, as shown in the example in Figure 1, or it may supply electromagnetic waves to the cavity from the side of the cavity container 32a. In this case, for example, two electromagnetic waves may be supplied from two mutually orthogonal directions toward the central axis of the cavity container 32a when viewed from the axial direction of the cavity container 32a. This may generate an electric field that rotates around a rotation axis that coincides with the central axis. The two electromagnetic waves may have the same frequency but be out of phase by π / 2. In addition, at each of a plurality of positions spaced apart in the axial direction of the cavity container 32a, two electromagnetic waves may be supplied from two mutually orthogonal directions toward the central axis of the cavity container 32a when viewed from the axial direction of the cavity container 32a, in order to generate the above-mentioned rotating electric field. In this case as well, the two electromagnetic waves may have the same frequency but be out of phase by π / 2. Furthermore, the electric field generator 32 that generates the above-mentioned rotating electric field may have other configurations (for example, known configurations).

[0047] <Configuration of the ion beam source> The ion beam directed to the passage region R is generated by the ion beam source 40 as shown in Figure 1. The ion beam source 40 generates an ion beam that travels to the passage region R and the target region T. This ion beam may be a beam of non-reactive particles (for example, a beam of protons or deuterons), or it may be a beam of ions of fusion reaction particles (for example, any of the reaction particles described above). The ion beam source 40 may or may not be a component of the fusion device 10.

[0048] The ion beam source 40, although not shown in the figure, may include an ion source, an accelerator, and a beam tuner. The ion source generates a large number of ions (e.g., protons). The accelerator accelerates each ion generated by the ion source. The beam tuner has multiple magnetic field coils that adjust the direction and spread of the large number of ions (ion beam) accelerated by the accelerator to match the passage region R and the target region T.

[0049] (Effects of the embodiment) According to the first embodiment, the following effects (A) to (J) can be obtained.

[0050] (A) The heating ion beam forming apparatus 30 applies a magnetic field and an electric field to the ion beam traveling towards the target region T where the plasma 1 or plasma generating gas is present, thereby causing each ion in the ion beam incident on the target region to swirl. As a result, a large number of swirling ions are incident on the target region T while swirling. Therefore, the plasma 1 or plasma generating gas can be heated by collisions between these swirling ions and particles of the plasma 1 or plasma generating gas.

[0051] Furthermore, because each swirling ion injected into the target region T is swirling, it travels a longer distance within the target region T compared to when it travels in a straight line. This allows the swirling ions to effectively collide with the particles of plasma 1 or the plasma-generating gas. Therefore, the plasma 1 or the plasma-generating gas can be effectively heated by the swirling ions.

[0052] For example, a heating ion beam forming device 30 can be used to inject a large number of swirling ions into the plasma generation gas in the target region T. At this time, the magnetic field generated by the confinement magnetic field generator 21 can confine the large number of swirling ions (ion ring IR) in the target region T. These swirling ions collide with particles in the plasma generation gas in the target region T, heating the plasma generation gas and creating plasma 1. Next, the heating ion beam forming device 30 can be used to continue injecting a large number of swirling ions into the target region T to heat the plasma 1. This can cause nuclear fusion between the reactive particles in plasma 1. Alternatively, in the target region T, the plasma generation gas may be heated by means other than the swirling ions from the heating ion beam forming apparatus 30 to create plasma 1, and then the plasma 1 may be heated by injecting a large number of swirling ions into the plasma 1 using the heating ion beam forming apparatus 30. This may cause nuclear fusion between the reactive particles in the plasma 1.

[0053] (B) The magnetic field generator 31 generates a magnetic field in the region R along the direction of travel D of the ion beam, and the electric field generator 32 generates an electric field having a component perpendicular to the axis along the direction of travel D. This electric field imparts a velocity component perpendicular to each ion in the ion beam, causing each ion with this perpendicular velocity component to revolve around the axis by the Lorentz force caused by the magnetic field. This allows each ion to be accelerated in the revolving direction while maintaining its velocity component in the direction of travel D. This increases the overall kinetic energy of each ion, and as a result, the plasma 1 or the plasma generation gas can be effectively heated by the revolving ions.

[0054] On the other hand, Non-Patent Document 1 describes how charged particles are made to follow a helical trajectory using the Cyclotron AutoResonance Accelerator (CARA), but it does not describe how these charged particles are used to heat the plasma or the gas used to generate the plasma.

[0055] (C) In Non-Patent Document 3, the plasma inside the fusion reactor is heated with a neutron beam, but there is a problem in that the equipment for injecting a high-energy neutron beam into the fusion reactor is large in scale. In contrast, in this embodiment, this problem can be avoided by heating the plasma with swirling ions as described above.

[0056] (D) The superconducting coil 31a can generate a strong magnetic field (for example, a magnetic field with a magnetic flux density of 1T or more, 3T or more, or 10T or more), thereby increasing the Lorentz force and reducing the rotation radius of the swirling ions. Consequently, the dimensions (inner diameter) of the cavity container 32a, etc., can be reduced.

[0057] (E) The electric field generator 32 continuously (repeatedly in the second embodiment described below) generates an oscillating electric field as an electric field perpendicular to the direction of rotation of each ion that is swirling due to the Lorentz force. As a result, the Lorentz force acting on the swirling ions increases continuously, and the swirling ions can be continuously (repeatedly in the second embodiment) accelerated in the direction of rotation (for example, the rotation radius can be gradually increased while keeping the rotation frequency constant). Therefore, the overall kinetic energy of the swirling ions can be further increased. As a result, the plasma 1 or the plasma generation gas can be heated more effectively by the swirling ions.

[0058] (F) As described above, the rotating electric field can continuously accelerate the swirling ions in the swirling direction, thus generating stable swirling ions. When a large number of these stable swirling ions are incident on the target region T, a stable ion ring IR can be formed in the plasma 1, resulting in low energy loss. In contrast, Non-Patent Literature 2 states that ion rings generated by a cusp magnetic field have strong anisotropy, which may lead to significant energy loss.

[0059] (G) The above-mentioned rotating electric field can be generated by supplying electromagnetic waves to the cavity R of the cavity container 32a. In this case, by generating standing waves of electromagnetic waves in the cavity R, the rotating electric field can be efficiently generated by these standing waves.

[0060] (H) The magnetic field generator 31 generates the magnetic field for swirling the ions using a coil made of a superconductor. This makes it possible to increase the magnitude of the magnetic field. In this case, the magnitude of the rotating electric field for swirling each ion can be suppressed, and as a result, the distance that the ions move in the orthogonal direction due to the rotating electric field facing the orthogonal direction can be suppressed so that the swirling radius of each ion does not become too large (not exceeding the inner diameter of the cavity container 32a) and can be kept at an appropriate size.

[0061] (I) The confinement device 20 can confine a large number of swirling ions (the ion ring IR described above) to the target region T. As a result, each swirling ion travels a long distance in the direction of its rotation within the target region T. Therefore, each swirling ion can be made to collide with the plasma 1 or the plasma generation gas particles in the target region T with a higher probability. Thus, after the plasma 1 is generated, it becomes possible to sustain a nuclear fusion reaction in the plasma 1. In this case, by continuously injecting a large number of swirling ions into the target region T using the ion beam source 40 and the heating ion beam forming device 30, it becomes possible to sustain a nuclear fusion reaction over a long period of time.

[0062] (J) The confinement magnetic field generator 21 can confine each swirling ion to the target region T by the magnetic field generated by the pair of coils 21a and 21b described above. However, the present invention is not limited thereto, and the plasma 1 and each swirling ion may be confined to the target region T by a confinement magnetic field generator 21 having other configurations.

[0063] [Second Embodiment] Figure 2 is a schematic diagram showing the configuration of a nuclear fusion device 10 according to a second embodiment of the present invention. For the second embodiment, matters not described below (such as configuration and operation) may be the same as in the first embodiment. In the nuclear fusion device 10 according to the second embodiment, the configuration of the electric field generator 32 differs from that of the first embodiment, but the other configurations may be the same as in the nuclear fusion device 10 according to the first embodiment.

[0064] In the second embodiment, the electric field generator 32 has a pair of electrodes 32e, 32f and a voltage application device 32g. In the second embodiment, the electric field generator 32 does not have an electromagnetic wave supply device 32b, a waveguide 32c, and a partition plate 32d, but it may have a hollow container 32a.

[0065] Figure 3A is a cross-sectional view taken along line III-III in Figure 2, but it shows only the cavity container 32a and a pair of electrodes 32e and 32f.

[0066] A pair of electrodes 32e and 32f are provided on one side and the other side of the passage region R, respectively, in a direction perpendicular to the aforementioned axis (the central axis of the cavity container 32a). For example, the pair of electrodes 32e and 32f are provided facing each other in a direction perpendicular to the passage region R. In the second embodiment, the passage region R may be the region (space) inside the cavity container 32a sandwiched between the pair of electrodes 32e and 32f. In the example of Figure 2, the pair of electrodes 32e and 32f face each other in a direction perpendicular to the passage region, and in this case, the direction in which the pair of electrodes 32e and 32f face each other will also be simply referred to as the opposing direction. The pair of electrodes 32e and 32f may be provided inside the cavity container 32a. The shape of the pair of electrodes 32e, 32f is flat in the example shown in Figure 2, but is not limited to this. For example, they may have other shapes as long as they have electrode surfaces 32e1, 32f1 facing the passing region R side.

[0067] The pair of electrodes 32e and 32f may, but are not limited to, having flat electrode surfaces 32e1 and 32f1 facing each other, as shown in Figures 2 and 3A. The electrode surfaces 32e1 and 32f1 may, but are not limited to, be parallel to the direction of travel D, and may be (for example, slightly) inclined from the direction of travel D. The pair of electrodes 32e and 32f may generate a substantially uniform electric field (electric field E1 in Figure 3A and electric field E2 in Figure 3B, which will be described later) in the region R through which they pass between each other.

[0068] The voltage application device 32g applies a voltage to a pair of electrodes 32e and 32f such that the pair of electrodes 32e and 32f repeatedly generate the aforementioned electric field (an electric field with a component in the orthogonal direction) between them as an oscillating electric field. For example, the voltage application device 32g applies a voltage to a pair of electrodes 32e and 32f such that the pair of electrodes 32e and 32f repeatedly generate an electric field oriented in opposite directions as an oscillating electric field. The electric field generated by the pair of electrodes 32e and 32f imparts an orthogonal velocity component to each ion in the ion beam. As a result, each ion with this orthogonal velocity component is rotated around an axis along the direction of travel D by the Lorentz force caused by the magnetic field generated in the passage region R by the magnetic field generator 31. The target region T (for example, the center of the target region T) may be located on the extension of this axis. For example, the axis may coincide with the center of the region (passage region R) between the pair of electrodes 32e and 32f.

[0069] In the second embodiment, the voltage application device 32g generates an electric field (or an electric field having a component in the direction of rotation) between a pair of electrodes 32e and 32f for each ion that is rotating due to the Lorentz force, as a repeatedly oscillating electric field by the pair of electrodes 32e and 32f. Here, the direction of rotation of the ion as seen from the ion changes depending on the position of the ion in the direction of rotation. Therefore, the voltage application device 32g applies a voltage to the pair of electrodes 32e and 32f such that the pair of electrodes 32e and 32f generate an electric field as shown in (i) or (ii) below. Here, the opposing directions that face opposite each other are referred to as the first opposing direction and the second opposing direction, respectively.

[0070] (i) A pair of electrodes 32e, 32f generate an electric field directed from one electrode 32e, 32f to the other at the same frequency as the rotation frequency of the swirling ion. This electric field may be, for example, an electric field E1 directed in the first opposing direction (the electric field E1 shown in Figure 3A). (ii) A pair of electrodes 32e, 32f alternately generate an electric field from one electrode 32e, 32f toward the other, and an electric field from the other electrode 32e, 32f toward the first, at a frequency twice the rotation frequency of the rotating ions. For example, the electric field from one electrode 32e, 32f toward the other may be an electric field E1 directed in a first opposing direction, and the electric field from the other electrode 32e, 32f toward the first may be an electric field E2 directed in a second opposing direction (the electric field E2 shown in Figure 3A). Figure 3B shows the state in Figure 3A where an electric field E2 is generated instead of an electric field E1.

[0071] Furthermore, the electrode surfaces 32e1 and 32f1 of the pair of electrodes 32e and 32f have sufficient length in the direction of travel D so that the swirling ions are sufficiently accelerated in the direction of swirl by the heating ion beam forming apparatus 30. The dimensions of the electrode surfaces 32e1 and 32f1 of such a pair of electrodes 32e and 32f may be larger in the direction of travel D than in the dimensions in the directions perpendicular to both the direction of travel D and the direction opposite to it. For example, the electrode surfaces 32e1 and 32f1 of the pair of electrodes 32e and 32f extend in a long manner from one side to the other in the direction of travel D (either in the direction of travel D or in a direction inclined from the direction of travel D).

[0072] Furthermore, the distance between the pair of electrodes 32e and 32f is set to be greater than the maximum swirling diameter of the swirling ion passing through the passage region R (the swirling diameter just before the swirling ion exits the passage region R in the direction of travel D1). In addition, the ion beam from the ion beam source 40 may be incident on the vacuum-state passage region R inside the cavity container 32a, for example, through a beam window (not shown). That is, although the cavity container 32a is in communication with the inside of the plasma container 22, it may be hermetically sealed from the outside.

[0073] In the second embodiment, the effects (A) to (J) described above in the first embodiment can also be obtained.

[0074] (Examples) Since the fusion apparatus 10 according to the first or second embodiment can heat the plasma 1 to a high temperature state in which nuclear fusion occurs, it can be implemented as follows.

[0075] In one embodiment of the first or second embodiment, nuclear fusion is performed using a DT reaction, D 3 He reaction, or p 11 It may be a B reaction. In this case, the heat generated by nuclear fusion in the nuclear fusion device 10 may be used to generate electricity. For example, the heat may be exchanged with water to turn the water into steam, and the kinetic energy of the rotation may be converted into electrical energy by rotating a turbine with the steam.

[0076] In the first embodiment or another embodiment of the second embodiment, the nuclear fusion described above is a reaction that generates neutrons (for example, a DT reaction or a DD reaction), and the nuclear fusion device 10 may be used as a neutron source. In this case, the neutron source may be used, for example, for the processing of high-level radioactive waste. That is, the neutrons generated by nuclear fusion in the neutron source are irradiated onto the radioactive waste to transmute the radioactive nuclides in the radioactive waste into shorter-lived radioactive nuclides or various non-radioactive substances.

[0077] In yet another embodiment of the first or second embodiment, nuclear fusion is a reaction that produces tritium (e.g., a DD reaction), and the nuclear fusion device 10 may be used as a tritium generator.

[0078] Furthermore, according to the present invention, nuclear fusion is a DT reaction, D 3 He reaction, p 11 Not limited to B reactions or DD reactions, but other types of nuclear fusion (e.g., TT reactions, T 3 He reaction, 3 He 3 This may also be a He reaction. Therefore, in this specification, the reaction particles may be, for example, deuterium, tritium, light hydrogen, boron, or helium-3.

[0079] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the technical idea of ​​the present invention. For example, the nuclear fusion apparatus 10 or heating ion beam forming apparatus 30 according to the first or second embodiment of the present invention does not have to have all of the above-described features, and may have only some of the above-described features.

[0080] Furthermore, to the extent that at least some of the above-mentioned problems can be solved, or to the extent that at least some of the effects described herein can be obtained, one or more of the claims and components described herein can be omitted, or any combination of the claims and components described herein is possible.

[0081] Furthermore, in the first or second embodiment, the heating ion beam forming apparatus 30 may, as described above, inject a large number of swirling ions into the target region T to heat the plasma generation gas in the target region T in order to generate plasma for purposes other than nuclear fusion. In this case, the nuclear fusion apparatus 10 is read as the plasma generation apparatus 10 above, but the plasma generation apparatus 10 has the same configuration as the nuclear fusion apparatus 10 described above, the plasma generation gas does not have to contain reaction particles, the content related to nuclear fusion is omitted, and other matters (configuration and operation) may be the same as described above. Also, in this case, the heating ion beam forming apparatus 30 may, as described above, further inject a large number of swirling ions into the target region T to heat the plasma 1 in the target region T. [Explanation of Symbols]

[0082] 1 Plasma 10. Nuclear Fusion Device (Plasma Generator) 20 Confinement device 21. Confinement Magnetic Field Generator 21a, 21b coils 22 Plasma container 23 Gas supply equipment 23a Piping 24 Exhaust system 24a Piping 30 Ion beam forming apparatus for heating 31 Magnetic field generator 31a Coil (Solenoid Coil) 31b Cryostat 32 Electric field generator 32a Hollow container 32b Electromagnetic wave supply device (microwave source) 32c waveguide 32d Partition Plate 32e,32f electrode 32e1,32f1 Electrode surface 32g Voltage Application Device 40 Ion beam sources D Direction of travel IR ion ring IT ion spiral orbit M1,M2 magnetic field lines T Target area R Passage area (cavity)

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