The present invention allows us to confine plasma in a fusion reactor using very strong electromagnetic fields. Strong electric and magnetic fields are optionally produced through usage of new type of conductors including superconductors invented by us that are functional at almost any temperature. However, it should be noted here that usage of these new type of conductors/superconductors is not a prerequisite for its proper operation. These strong fields also serve to heat up the plasma which would aid in the fusion reactions. The invention described herein also makes use of the electric fields produced by electrostatic charges.
Fusion reactions take place at extremely high temperatures of around 100 million degrees. Therefore, it is not possible to contain such a hot plasma in a physical container. Therefore, attempts have been made to confine the plasma using very strong magnetic fields which would cause the charged particles to circle around the magnetic field lines. Such attempts have not been very successful in producing fusion power in a sustained manner.
One such attempt was to bend a solenoid into a torus. When a current is passed through the coil of the torus, magnetic field lines would be circles along the torus. It was expected that the charged particles would be trapped circling around these field lines. However, it was observed that the electrons drifted away from the nuclei leading to large voltages. It was observed that the plasma ring would expand and hit the walls of the reactor.
Attempts were made to develop a system known as z-pinch to contain the hot plasma. Due to Lorentz force, parallel currents in the plasma cause the plasma to stay together thereby eliminating the need to use external magnets for the plasma confinement. Various teams in the UK built experimental devices to study the feasibility in late 1940s. However, they were unsuccessful in their attempts.
Former German scientist Ronald Richter living in Argentina, completed the Huemul Project in 1951 using electrical arcs and mechanical compression (sound waves) for heating and confinement but without success.
Project Matterhorn led by Spitzer in 1951 tried to correct the problem of outward drift toward the reactor walls by twisting one end of the torus compared to the other forming a figure resembling 8. This way magnetic lines were no longer circular but rather travelled closer and farther from the torus center. So, now a charged particle would travel in and out across the minor axis of the torus. Various layouts of the coil magnets were tried but failed to achieve the desired outcome. To heat the plasma to high temperatures, Spitzer used magnetic pumping which consisted of usage of a radio frequency source. He chose frequency of the source to be the same as the cyclotron frequency. This would cause charged particles to gain energy and try to move in wider radius resulting in collisions with other particles raising temperature of the plasma. However, all these efforts still did not yield the desired results.
By mid-1960s the tokamak designs by Russian scientists began to show greatly improved performance. Even though it was met with great skepticism initially, by 1969 it generated a mad rush for building tokamak type of fusion reactors all over the scientific world. Unlike the stellarator, a large circular current is made to pass through the plasma contained in the torus by the circular magnetic lines produced by the coil of the torus. This current is generated by a transformer type of action using the inner poloidal field coils acting as the primary of the transformer. This current serves a dual purpose of aiding in the confinement as well as ohmic heating of the plasma. Outer poloidal field coils are used for positioning as well as shaping of the plasma. The result is that helical magnetic field lines are generated which tend to confine the plasma. Even though it seems to improve the performance of the fusion reactor, it still does not lead to a stable steady state needed for a practical power generation.
Tokamak fusion reactors have not yet reached the breakeven point characterized by Q=1. The European tokamak (JET) holds the current record which succeeded in generating Q=0.67. In 2006, ITER (International Thermonuclear Experimental Reactor) was organized with seven international partners. Their aim is to achieve Q≥10. For this they intend to use a confining magnetic field of 5.3 Tesla and pass a current of about 15 mega amperes through the plasma. An input thermal power of 50 megawatts is needed to raise temperature of the plasma to about 150 million degrees Celsius. It is expected that it would generate at least 500 megawatts of thermal power. This would generate a “burning” plasma with helium nuclei (alpha particles) carrying about 20% of the energy and the rest 80% is carried by the generated neutrons. Neutrons not being charged would freely hit the walls and the resulting heat would then be utilized for generation of pressurized hot steam that can drive a turbine for generation of electricity. Three heating systems will be utilized: electron cyclotron resonance heating (ECRH), capable of injecting up to 20 megawatts of thermal energy; ion cyclotron radio frequency heating (ICRF), with a similar 20 megawatts maximum heating capability; and the neutral beam (NB) heating system, capable of injecting a maximum of 33 megawatts into the plasma. Thus, 73 megawatts of plasma heating will be available for ITER operation, well above the 50 megawatts required. It will be using 400 second pulses. They expect to test ITER operation by 2035.
Here we describe procedures and mechanisms to produce an entirely new class of machines to harness the fusion power by a novel scheme for the plasma confinement and heat generation. This machine would allow for a far superior confinement of the hot plasma. It also provides for relatively easy control of both confinement as well as heating. One of the mechanisms to achieve this is to independently control the population densities of the positively charged nuclei as well as the electrons. In addition, it requires far smaller energy input to achieve the desired results than any of the current or planned fusion machines resulting in far greater value for Q than any of the existing or planned fusion machines. This machine is expected to work in a steady state mode.
Some embodiments of the present invention are illustrated as an example and are not limited by the figures of the accompanying drawings, in which like references may indicate similar elements and in which a reference to a figure refers to all its parts. In general, part B of a figure, herein, reveals the internal details of the system or component through a vertical cut up or cross section of the system or component. Sometimes, the internal details may be revealed by simply lifting the lid. Explicit electrical connections are not part of the drawings herein. A brief description of the drawings is as follows:
The terminology used herein is only to describe particular embodiments of our invention and should not be regarded as limiting of the invention. Herein, the term “and/or” would include any and all combinations of one or more associated items. Singular words such as “a”, “an,” and “the” are used herein to include both the singular as well as plural meanings, unless the context clearly indicates otherwise. In addition, usage of the terms “comprises” and/or “comprising” are intended to mean not only the stated elements, components, features, steps, and operations, but may also mean presence or addition of other elements, components, features, steps, and operations, or a combinations thereof.
Unless otherwise stated, all terms, including scientific/technical terms used herein, would have the same meaning as commonly used by a person having ordinary skills in the art related to the invention described herein. It should be understood that the terms used herein, should not necessarily be used in the formal or idealized sense, as defined by commonly used dictionaries, but rather their meaning must be understood in the context of the relevant art and the current disclosure.
In disclosing the invention, a number of steps and techniques are described herein. Each one of these has its own particular benefit. However, each one of these can be used in a partial or full combination of all of them. All of these combinations will not be described here because that is not necessary to describe the invention. However, all of these combinations are within the scope of the invention, including the specification and claims, disclosed herein.
Controlled fusion power machine, apparatuses, concepts, and methods for producing various components, and features are discussed herein. In the disclosure herein, many of the specific details are meant to help one understand the invention. However, it should be clear to anyone with ordinary skills in the relevant art that the invention would work just fine even without these specific details.
The disclosure of the invention herein should be considered only as an example of the invention and must not be considered as limited to specific embodiments of the invention as illustrated by drawings/figures or description herein.
The present invention will now be described by referencing the appended figures illustrating a number of preferred embodiments. Here, we describe an entirely new class of controlled fusion power machine. Methods or procedures for producing a plasma wherein concentration of positively charged nuclei and negatively charged electrons can be independently controlled, are described herein. This would allow us to produce extremely large currents in the plasma without causing instabilities. In fact, a large current would tend to help confine the plasma due to the “pinching” effect. A combination of very strong magnetic, electric, and electrostatic fields is used to contain the plasma. Various means of heating the plasma are described herein. Presence of extremely large plasma currents, independent control of the concentrations of positively charged nuclei and negatively charged electrons, and effective control of various fields contribute significantly to the goal of heating the plasma without causing instabilities. Even though it is not mandatory, extensive use of a new class of superconductors at room temperatures may be made to produce very strong magnetic fields for effective containment of the plasma. However, it is expected that the controlled fusion power machine described herein may not require as strong magnetic fields as the ITER machine being pursued currently. In addition, production of these very strong magnetic fields would require only a very small fraction of the energy input needed for production of the same in the ITER machine. This would lead to a Q value that would be orders of magnitude higher than the one expected for the ITER machine. Our controlled fusion power machine would operate in a steady state mode. Preferred embodiments of the mechanism to achieve this is described next:
Magnetic field represented by the field lines 1 (depicted in
Positively charged nuclei enter the reaction chamber or container 8 through the tube 10 in
Neutral beam injection into reaction chamber 8 is carried out through tube 12. Neutral beam is used for heating of plasma through collisions with various constituent particles in reaction chamber 8.
An auxiliary magnetic field 5 (
Conductor 14, as illustrated in
Now, operation of the controlled fusion power machine, described above, would be detailed herein. After the positively charged nuclei and negatively charged electrons are injected in the opposite directions into the reaction chamber 8, they would tend to circle around the z-axis in the opposite directions on planes perpendicular to the z-axis due to the presence of the magnetic field 1, as depicted in
By superimposing a time-varying component of electric current through coil 9, we would also generate the circular electric field 3. The induced electric field strength would increase with distance from the z-axis. An auxiliary electric field can also be generated by passing a time-varying current through coil 16. The associated electric field lines would also form along the concentric circles as illustrated by 3. However, strength of this induced electric field would decrease with distance from the z-axis. Therefore, it would tend to even out the electric field strength throughout the plasma. We would need to synchronize the time varying components of the currents through the two coils (9 and 16). The combined electric field would tend to accelerate the charged particles resulting in larger currents thereby causing larger ohmic heating of the plasma. The plasma would tend to remain confined away from the walls of the reaction chamber due to the presence of strong static component of magnetic fields 1 and 2 along with the electrostatic fields 4(4a and 4b), 6 and 7 as illustrated in
It may be noted here that it is not necessary to use all the electric and magnetic fields at the same time to effectively confine the plasma. Different combinations of these fields may be enough for effective confinement of the plasma. As an extreme example, it should be enough to confine the plasma by simply establishing very large positive charge densities on the walls of the reaction chamber and using a very large value for PCR. It would tend to minimize energy input at the cost of having to use much larger size for the reaction chamber. In addition, the reaction chamber itself would need to be enclosed by a larger vacuum chamber to avoid sparking and charge leakage. In the preferred embodiments of the invention, described above, superconductor or near-superconductor structures are built into the design of the machine itself. However, we could have used the superconductors or very low resistivity conductors as stand-alone components in the machine. It may also be noted herein that these type of superconductors or very low resistivity conductors that are functional at almost any temperature are based on another patent filing by us. It is important to note that usage of superconductors or very low resistivity conductors is not necessary for successful operation of the invention described herein. It may be noted that usage of electrostatic fields to increase electrical conductivity of a component also has a bearing on the thermal conductivity of the same.
There is a scope for vastly improving confinement of the hot plasma inside a tokamak by employing some of the mechanisms or procedures described above. So, the following changes to the design of the current tokamaks will vastly improve confinement of the hot plasma inside a tokamak: The particle concentration ratio (PCR) should be made much greater than 1 and equal to an optimum value. Electrons should be injected into the torus in a direction opposite to that of the positively charged nuclei. It is desirable to accelerate both the positively charged nuclei as well as the negatively charged electrons to high speeds before being injected into the torus in presence of the magnetic field produced by the torus coil. The torus wall should be positively charged to repel any dominant positively charged nuclei that may drift toward the wall of the torus. If we add another high current capacity wire cable along the z-axis inside the inner poloidal field coils, it can be made to add to the strong magnetic field produced by the large current through the torus coil. This additional magnetic field can be used to control or modulate the original magnetic field produced by the current in the torus coil. With these changes, we may not need the outer poloidal field coils. With much better confinement of the plasma now, it would be possible to operate in the desirable steady state mode by passing a time varying current through the inner poloidal field coils. In addition, by superimposing a time-varying current on the existing static current through the torus coils, thermalization and hence ohmic heating can be made more effective.
Number | Date | Country | |
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63298787 | Jan 2022 | US |