Laser fusion fast ignition efficient heating system and method based on magnetic field guidance

Abstract

The invention belongs to the technical field of nuclear power generation, and particularly relates to a laser fusion fast ignition efficient heating system and method based on magnetic field guidance. The invention discloses a laser fusion fast ignition efficient heating method based on magnetic field guidance. The method comprises the following steps: 1) generating a guide magnetic field by using an electromagnetic means; (2) enabling picosecond laser to interact with the heating gold cone and / or other substances to form a high-energy charged particle beam; and (3) heating the compressed thermonuclear fuel by the high-energy charged particle beam obtained in the step (2) under the guiding action of the guiding magnetic field obtained in the step (1) and the heating gold cone. The high-energy charged particle beam is restrained and collimated by utilizing the guide magnetic field, so that the laser energy is deposited in the thermonuclear fuel as much as possible, the conversion efficiency from the picosecond laser energy to the hot spot internal energy is remarkably improved, and the application requirement of laser fusion energy is met.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power generation, and in particular relates to a laser fusion fast ignition and high-efficiency heating system and method based on magnetic field guidance. Background Art

[0002] In the 1960s, Nuckols of the United States and Academician Wang Ganchang of my country independently proposed the concept of using lasers to achieve nuclear fusion. In 2022, the National Ignition Facility of the United States adopted an indirect drive central ignition technology route, achieving output energy greater than laser input energy for the first time in human history, successfully verifying the scientific feasibility of laser controlled nuclear fusion. However, the laser indirect drive central ignition technology route it adopted has certain intrinsic physical difficulties, including low energy utilization efficiency and strong implosion fluid instability, so it is difficult to meet the high gain requirements required for commercial fusion energy.

[0003] In 2018, after carefully analyzing the research progress in the laser fusion field over the past few decades, Chinese scientist Academician Zhang Jie proposed the double cone collision ignition scheme (DCI) based on his original shell-in-cone idea in 1997. This scheme combines the advantages of the direct drive technology route with the advantages of the fast ignition technology route. While further improving the compression efficiency, it separates the compression and heating ignition processes of thermonuclear fuel, which is conducive to the fine control of the entire fusion compression and ignition process, and achieves high-gain fusion ignition with smaller laser energy. This scheme has great application prospects in low-cost, high-gain and high-efficiency controlled nuclear fusion power generation, but how to achieve rapid heating of compressed fuel is still an open problem worthy of in-depth study. Summary of the invention

[0004] In view of the shortcomings in the prior art, the present invention provides a laser fusion fast ignition and efficient heating system and method based on magnetic field guidance, which is used to solve the defects of the existing fast ignition schemes in terms of energy transfer efficiency, fast electron directional control and energy deposition locality in the process of realizing rapid heating of compressed fuel.

[0005] The present invention provides a laser fusion fast ignition and efficient heating method based on magnetic field guidance, the method comprising:

[0006] 1) Use electromagnetic means to generate a guiding magnetic field;

[0007] 2) using picosecond lasers to interact with heated gold cones and / or other materials to form high-energy charged particle beams;

[0008] 3) The high-energy charged particle beam obtained in step 2) heats the compressed thermonuclear fuel under the guidance of the guiding magnetic field obtained in step 1) and the heating gold cone.

[0009] In some embodiments of the present invention, the electromagnetic means described in step 1) is one or more of the interaction between nanosecond laser and capacitor coil target, pulsed strong magnetic field compressed and amplified by magnetic freezing effect, or inverse Faraday effect.

[0010] In some embodiments of the present invention, the guiding magnetic field described in step 1) is along the heating direction and covers the high-energy charged particle beam transport area; the magnetic induction intensity of the guiding magnetic field is ≥1000 Tesla; the duration of the guiding magnetic field is ≥10 picoseconds; and the radius of the area where the guiding magnetic field exists is 30-100 microns.

[0011] In some embodiments of the present invention, the total energy of the picosecond laser in step 2) is ≥ 20,000 joules; the peak laser intensity of the picosecond laser is ≥ 1x10 20 Watts / square centimeter; the laser pulse of the picosecond laser lasts for 3-20 picoseconds; the laser focal spot diameter of the picosecond laser is ≤50 microns.

[0012] In some embodiments of the present invention, the charged particles in the high-energy charged particle beam in step 2) are selected from one or more of fast electrons, protons or heavy ions.

[0013] In some embodiments of the present invention, the other substances in step 2) are selected from one or more of metal films, crystal films, and polymer films.

[0014] In some embodiments of the present invention, the opening angle of the heating gold cone in step 3) is 50-80°; the bottom of the heating gold cone is sealed, and the bottom radius is 10-30 microns.

[0015] In some embodiments of the present invention, the distance between the heated gold cone and the compressed thermonuclear fuel in step 3) is 30-100 microns.

[0016] In some embodiments of the present invention, the heating in step 3) is to 5-12 keV.

[0017] The present invention also provides a laser fusion fast ignition and high-efficiency heating system based on magnetic field guidance, comprising:

[0018] A nanosecond laser light source and a capacitor coil target, wherein the nanosecond laser beam emitted from the nanosecond laser light source is focused on the capacitor coil target to generate a guiding magnetic field along a heating direction and covering a transport region of the high-energy charged particle beam;

[0019] A picosecond laser light source and a heating gold cone, wherein a picosecond laser beam emitted from the picosecond laser light source targets the heating gold cone, interacts with the heating gold cone and / or other substances to form a high-energy charged particle beam, and under the guidance of the heating gold cone and the guiding magnetic field, targets and heats the compressed thermonuclear fuel; the other substances are arranged inside the heating gold cone.

[0020] The present invention has the following beneficial effects:

[0021] The present invention guides the high-energy charged particle beam by utilizing a guiding magnetic field along the heating direction (high-energy charged particle beam to thermonuclear fuel) and covering the transport area of ​​the high-energy charged particle beam, thereby achieving concentrated and directional transport, and maximizing the deposition of its energy in the compressed high-density thermonuclear fuel, thereby achieving the effect of efficient heating. At the same time, the high-intensity magnetic field generated by a high-energy nanosecond laser and a capacitor coil target or other electromagnetic means and the auxiliary guidance of a heating gold cone further improve the directionality of the high-energy charged particle beam, reduce its divergence angle, and significantly improve the conversion efficiency of picosecond laser energy to the internal energy of the hot spot, with an energy conversion efficiency of 10%-20% (the energy conversion efficiency of existing heating methods is <5%, generally around 1%), meeting the application needs of future laser fusion energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the principle of efficient fast electron ignition heating guided by magnetic field in Example 1 of the present invention.

[0023] Figure 2 Schematic diagram of the transport of a high-energy charged particle beam under the action of a guided magnetic field in Example 1 of the present invention.

[0024] Figure 3 Schematic diagram of the temperature and density of the thermonuclear fuel after being heated by a high-energy charged particle beam in Example 1 of the present invention.

[0025] Component number description

[0026] 1 Nanosecond laser source

[0027] 2 Capacitor coil target

[0028] 3 Picosecond laser source

[0029] 4 Heating the gold cone

[0030] 5 Compressed Thermonuclear Fuel DETAILED DESCRIPTION

[0031] The following describes in detail the embodiments of the highly efficient heating system and method of the specifically disclosed magnetic field-guided laser fusion fast ignition scheme.

[0032] The present invention uses a guiding magnetic field along the heating direction that can cover the high-energy charged particle beam transport area to guide the high-energy charged particle beam, realize concentrated and directional electron transport, so that it can deposit as much energy as possible in the compressed high-density thermonuclear fuel, and realize efficient heating. At the same time, the high-energy charged particle beam can be further guided by a heating gold cone, and the conversion efficiency of the heated picosecond laser energy to the fuel internal energy is 10%-20%, which meets the application requirements of future laser fusion energy. On this basis, the present invention is completed.

[0033] See also Figure 1 to Figure 3 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0034] On the one hand, the present invention provides a laser fusion fast ignition and efficient heating method based on magnetic field guidance, the method comprising:

[0035] 1) Use electromagnetic means to generate a guiding magnetic field;

[0036] 2) using picosecond lasers to interact with heated gold cones and / or other materials to form high-energy charged particle beams;

[0037] 3) The high-energy charged particle beam obtained in step 2) heats the compressed thermonuclear fuel under the guidance of the guiding magnetic field obtained in step 1) and the heating gold cone.

[0038] In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, "fast ignition" is a professional term in the field of fusion research. The fusion technology route of the present invention is fast ignition, which specifically refers to igniting compressed high-density fusion fuel by high-energy laser or other external energy sources to achieve inertial confinement fusion. In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, the electromagnetic means described in step 1) is one of the pulsed strong magnetic field or the inverse Faraday effect that is compressed and amplified by the nanosecond laser and the capacitor coil target. In a specific embodiment, a guiding magnetic field is generated by the interaction between the nanosecond laser and the capacitor coil target, and the energy of the nanosecond laser is 2 kilojoules, the pulse width is 1 nanosecond, and the wavelength is 1054 nanometers.

[0039] In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, the nanosecond laser interacts with the capacitor coil target to generate a guiding magnetic field. The specific process is that when the nanosecond laser pulse irradiates the capacitor coil target, the laser energy quickly heats the target surface and generates a large amount of hot plasma. Since the electron movement speed is much faster than that of ions, the emitted hot electrons are first captured by the front target disk to make it negatively charged, while the rear target disk is positively charged. The potential difference between the two target disks drives the metal coil to generate a strong current and a corresponding strong magnetic field. The magnetic field lasts for several nanoseconds.

[0040] The specific process of generating the pulsed strong magnetic field compressed and amplified by the magnetic freezing effect is as follows: First, a pulsed strong magnetic field is generated by a pulse power supply and a pulsed magnet. At this time, the magnetic induction intensity is tens of Tesla and the duration can reach the millisecond scale. After the magnetic field enters the thermonuclear fuel that has not yet been compressed, the thermonuclear fuel is compressed again. At this time, due to the magnetic freezing effect of the magnetic fluid, the magnetic field will be further compressed and amplified to achieve a magnetic field of the order of thousands of Tesla. The time scale of the compression and amplification process is a few nanoseconds.

[0041] The inverse Faraday effect refers to the use of circularly polarized high-intensity pulsed lasers interacting with low-density plasma to generate a magnetic field. The electric field portion of the circularly polarized electromagnetic wave can induce an electric current, which will generate a static magnetic field according to Maxwell's equations.

[0042] In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, the guiding magnetic field in step 1) refers to a magnetic field that guides charged particles to move along a predetermined path in a specific spatial region by controlling the direction and intensity of the magnetic field, and its main functions include controlling particle trajectories, focusing particle beams, and stabilizing particle motion. In a specific embodiment of the present invention, the guiding magnetic field covers the high-energy charged particle beam transport area along the heating direction; the magnetic induction intensity of the guiding magnetic field is ≥1000 Tesla. If the magnetic induction intensity is lower than the range, it will not produce sufficient lateral confinement effect on the high-energy charged particle beam, resulting in some high-energy electrons being unable to be injected into high-density thermonuclear fuel, resulting in a decrease in heating efficiency. The duration of the guiding magnetic field is ≥10 picoseconds; the radius of the area where the guiding magnetic field exists is 30-100 microns, which can be selected as 30-50 microns, 50-80 microns or 80-100 microns, and preferably 30 microns, 50 microns or 100 microns.

[0043] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the total energy of the picosecond laser in step 2) is ≥ 20,000 joules; the peak laser intensity of the picosecond laser is ≥ 1x10 20 Watts / square centimeter; the laser pulse duration of the picosecond laser is 3-20 picoseconds, which can be 3-10 picoseconds, 10-12 picoseconds, 12-16 picoseconds, 16-20 picoseconds or 10-20 picoseconds, etc., preferably 10 picoseconds; the diameter of the laser focal spot of the picosecond laser is ≤50 microns. Picosecond laser parameters that are inferior to the above range will result in the inability to heat the thermonuclear fuel to the fusion ignition temperature.

[0044] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the charged particles in the high-energy charged particle beam in step 2) are selected from one or more of fast electrons, protons or heavy ions. When the charged particles in the high-energy charged particle beam are fast electrons (i.e., electrons with high kinetic energy), the total energy of the high-energy charged particle beam is ≥10,000 joules, the beam spot diameter is ≤50 microns, and the beam divergence angle is ≤50 degrees. In a specific embodiment of the present invention, the picosecond laser in step 2) interacts with a heated gold cone (heated gold cone bottom) to produce fast electrons; when the picosecond laser interacts with other substances (such as metal films, crystal films or polymer films), protons or heavy ions are produced in addition to fast electrons.

[0045] In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, the other substances in step 2) are selected from one or more of metal films, crystal films, and polymer films. The metal in the metal film can be, for example, gold, copper, aluminum, silver or titanium, the crystal in the crystal film can be, for example, diamond, graphene, silicon carbide or gallium nitride, and the polymer in the polymer film can be, for example, polyethylene, polypropylene, polystyrene or polyethylene terephthalate. The thickness of the film is different depending on the type of particles and the physical mechanism. For example, the thickness of the metal or crystal film can be 5-30 nanometers, and the thickness of the metal film or polymer film can be 1-100 micrometers. In a specific embodiment of the present invention, the other substances are arranged inside the heating gold cone.

[0046] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the compressed thermonuclear material in step 3) refers to a fusion material with high density after being compressed by laser compression or other means, which can produce a nuclear fusion reaction under high temperature and high pressure and release a large amount of energy. In a specific embodiment of the present invention, the surface density of the compressed thermonuclear material is ≥0.6 g / cm2, the density is ≥200 g / cm3, and the fuel component is deuterium-tritium, deuterium-deuterium, carbon-deuterium, etc.

[0047] In the laser fusion fast ignition and efficient heating method based on magnetic field guidance provided by the present invention, the main function of the heated gold cone in step 3) is to heat the surface of the gold cone by laser during the experiment to produce a physical effect of high energy density. Its unique cone design helps to concentrate energy, thereby achieving efficient energy transfer and heating effects. In a specific embodiment of the present invention, when the picosecond laser only interacts with the heated gold cone, the heated gold cone can act as a "matter" to generate fast electrons with the picosecond laser, and then assist in guiding the fast electrons, that is, the heated gold cone participates in the role of "acting substance" and "assisting guidance" at the same time. When the picosecond laser interacts with other substances, such as metal films, crystal films, and polymer films, protons or heavy ions other than fast electrons can be generated. At this time, the other substances only play the role of "matter" that interacts with the picosecond laser to generate high-energy particle beams, and the heated gold cone only plays the role of assisting guidance.

[0048] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the opening angle of the heating gold cone in step 3), that is, the cone angle of the heating gold cone, is 50-80°, for example, it can be 50-60°, 60-70° or 70-80°, preferably 50°, 60° or 70°. The opening angle of the heating gold cone within this range can effectively concentrate and guide the direction of the high-energy charged particle beam, ensuring that the high-energy charged particle beam is not easy to scatter when passing through the heating, and maintaining efficient energy transport. The bottom of the heating gold cone, that is, the end close to the thermonuclear fuel, is sealed, and the bottom radius is 10-30 microns, which can be 10 microns or 20 microns. This design can further focus the high-energy charged particle beam, so that it is more concentratedly deposited in the compressed thermonuclear fuel, which helps to form a denser hot spot and improve the heating efficiency.

[0049] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the distance between the bottom of the heating gold cone and the center of the compressed thermonuclear fuel in step 3) is 30-100 microns, which can be 30-50, 50-70, 70-80, 80-100, 50-80 or 30-80, etc., preferably 30 microns, 50 microns or 80 microns. If the distance is too close, the gold cone will be destroyed by the compressed fuel, and if it is too far, the heating efficiency will decrease.

[0050] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, in step 3), the high-energy charged particle beam deposits energy in the compressed thermonuclear fuel to realize the conversion of picosecond laser energy to hot spot internal energy, and heats the thermonuclear fuel to the fusion temperature within 3-20 picoseconds, which can be 3-10 picoseconds, 10-15 picoseconds, 15-20 picoseconds or 10-20 picoseconds, etc., preferably 10 picoseconds, and heats to 5-12 keV (i.e., 58.02 million-139 million ° C), which can be 5-8 keV, 8-10 keV, 5-10 keV or 10-12 keV, preferably 10 keV, to meet the temperature requirements of the fusion reaction. When the required fusion reaction temperature is reached, the compressed fuel undergoes a fusion reaction, releasing a large amount of energy.

[0051] In the magnetic field-guided laser fusion fast ignition and efficient heating method provided by the present invention, the "high efficiency" specifically refers to the high energy conversion efficiency of picosecond laser energy to hot spot internal energy. The energy conversion efficiency of the present invention can be directly obtained in the mathematical algorithm and model executed by the computer during the numerical simulation process. The specific formula is: energy conversion efficiency = improved hot spot internal energy / picosecond laser energy. In a specific embodiment of the present invention, the heating method of the present invention can achieve an energy conversion efficiency of 10-20% from picosecond laser energy to hot spot internal energy, which can be selected as 10-12%, 12-14%, 14-16%, 16-17%, 17-19%, 19-20%, 16-19% or 10-19%, etc., preferably 10%, 15% or 20%, etc. The energy conversion efficiency of existing heating methods is <5%, generally around 1%, so the present invention greatly improves the energy conversion efficiency of the heating method and meets the application requirements of laser fusion energy.

[0052] The embodiment of the present invention provides a laser fusion fast ignition and efficient heating system based on magnetic field guidance, such as Figure 1 As shown, including:

[0053] A nanosecond laser light source 1 and a capacitor coil target 2, wherein the nanosecond laser light source 1 is directly opposite to the capacitor coil target 2 to ensure that the nanosecond laser beam is vertically incident on the capacitor coil target 2, and the nanosecond laser beam emitted from the nanosecond laser light source 1 is focused on the capacitor coil target 2 to provide a guiding magnetic field along the heating direction and covering the transport region of the high-energy charged particle beam;

[0054] A picosecond laser light source 3 and a heating gold cone 4, wherein the picosecond laser light source 3 is directly opposite to the heating gold cone 4 to ensure that the picosecond laser beam is completely injected into the heating gold cone 4, and the picosecond laser beam emitted from the picosecond laser light source 3 targets the heating gold cone 4, interacts with the heating gold cone 4 and / or other substances to form a high-energy charged particle beam, and under the guidance of the heating gold cone 4 and the guiding magnetic field, targets the compressed thermonuclear fuel 5 for heating; the other substances are arranged inside the heating gold cone 4.

[0055] The heating gold cone 4 is arranged in the guiding magnetic field generated by the interaction between the nanosecond laser light source 1 and the capacitor coil target 2. The heating gold cone 4 only needs to be arranged in the guiding magnetic field, and the direction of the generated charged particle beam is parallel to the direction of the magnetic field. There are no special requirements for the orientation and distance. For example, the heating gold cone 4 can be arranged in the four orientations of the nanosecond laser light source 1 and the capacitor coil target 2, such as the upper, lower, left, and right. In the specific implementation process of those skilled in the art, the distance between the heating gold cone 4 and the nanosecond laser light source 1 and the capacitor coil target 2 can be adjusted according to the size of the experimental site and the volume of the device for emitting nanosecond laser or picosecond laser.

[0056] Working principle of the present invention:

[0057] First, a nanosecond laser is used to interact with a capacitor coil target or other electromagnetic means to generate a high-intensity guiding magnetic field along the heating direction that can cover the fast electron transport area. Subsequently, a high-energy charged particle beam is generated by the interaction of a high-energy, high-power picosecond laser with a heated gold cone and / or other substances. The generated high-energy charged particle beam is directed to the compressed thermonuclear fuel under the guidance of the guiding magnetic field and the heated gold pile. Due to the effect of the guiding magnetic field, the divergence angle of the high-energy charged particle beam is reduced, and more charged particles can be transported to high-density areas and deposit energy in the thermonuclear fuel, thereby achieving a charged particle heating process with higher energy conversion efficiency and forming a hot spot. At the same time, the use of a heated gold cone to assist in guiding the high-energy charged particle beam can further improve the directionality of the charged particles.

[0058] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail below in conjunction with embodiments and drawings.

[0059] Example 1

[0060] Laser fusion fast ignition and efficient heating method based on magnetic field guidance

[0061] like Figure 1 As shown, first, the nanosecond laser interacts with the capacitor coil target to generate a high-intensity guiding magnetic field along the heating direction, which can cover the high-energy charged particle beam transport area and the fast electron transport area. The magnetic induction intensity of the guiding magnetic field is 1000 Tesla; the duration of the guiding magnetic field is 100 picoseconds; and the radius of the area where the guiding magnetic field exists is 50 microns. Subsequently, the high-energy charged particle beam generated by the interaction between the high-energy and high-power picosecond laser and the bottom of the gold cone is directed to the compressed high-density thermonuclear fuel under the action of the guiding magnetic field. The total energy of the picosecond is 40,000 joules; the peak laser intensity is 3.9x10 20 Watts / square centimeter; the laser pulse duration is 10 picoseconds; the diameter of the laser focal spot is 30 microns. At the same time, an additional heating gold cone is used to assist in guiding fast electrons to further improve the directionality of the high-energy charged particle beam. The opening angle of the heating gold cone is 50 degrees, the bottom of the heating gold cone is sealed, and the bottom radius is 15 microns. After magnetic field guidance, the conversion efficiency of picosecond laser energy to hot spot internal energy can reach 17%.

[0062] The schematic diagram of the transport of high-energy charged particle beams under the action of a guided magnetic field is shown in Figure 2As shown in the figure, the first row of pictures shows the density distribution of high-density thermonuclear fuel, and the second row of pictures shows the equivalent current of fast electron transport. After applying the guiding magnetic field, the fast electrons make spiral motion along the magnetic field lines, so the directivity is greatly improved. It can be clearly seen from the figure that when there is no magnetic field, the distribution of fast electrons is relatively scattered and the incidence depth is shallow. After adding a 2,000 Tesla magnetic field along the heating direction that can cover the high-energy charged particle beam transport area, the fast electron current is significantly enhanced and the directivity is excellent.

[0063] Schematic diagram of the temperature and density of thermonuclear fuel after being heated by a high-energy charged particle beam. Figure 3 As shown, in Example 1, the fast electrons generated by the 40,000 joule picosecond laser energy within 10 picoseconds are transported to the compressed high-density thermonuclear fuel under the guidance of the magnetic field, and deposit energy in the fuel, rapidly heating the fuel to 10 kiloelectron volts, that is, an ultra-high temperature of 116 million degrees Celsius, meeting the temperature requirements of the fusion reaction, and releasing 10 million joules of fusion energy in the subsequent fusion reaction. In Example 1, the conversion efficiency of the picosecond laser energy to the internal energy of the hot spot is as high as 17%.

[0064] Example 2

[0065] The heating method is basically the same as that in Example 1, except that the total energy of the picosecond laser is changed to 30,000 joules. In Example 2, the conversion efficiency of the picosecond laser energy to the internal energy of the hot spot is 16%.

[0066] Example 3

[0067] The heating method is basically the same as that in Example 1, except that the total energy of the picosecond laser is changed to 50,000 joules. In Example 3, the conversion efficiency of the picosecond laser energy to the internal energy of the hot spot is 19%.

[0068] Example 4

[0069] The heating method is basically the same as that in Example 1, except that the total energy of the picosecond laser is changed to 20,000 joules. In Example 4, the conversion efficiency of the picosecond laser energy to the internal energy of the hot spot is 10%.

[0070] Comparative Example 1

[0071] The heating method is basically the same as that in Example 1, except that the total energy of the picosecond laser is changed to 10,000 joules. In Comparative Example 1, the conversion efficiency of the picosecond laser energy to the internal energy of the hot spot is only 6%.

[0072] The above examples are for the purpose of illustrating the embodiments disclosed by the present invention and are not to be construed as limiting the present invention. In addition, the various modifications listed herein and the variations of the methods in the invention are obvious to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been specifically described in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. In fact, various modifications as described above that are obvious to those skilled in the art to obtain the invention should be included within the scope of the present invention.

Claims

1. A laser fusion fast ignition and efficient heating method based on magnetic field guidance, characterized in that: The method comprises: 1) Use electromagnetic means to generate a guiding magnetic field; 2) using picosecond lasers to interact with heated gold cones and / or other materials to form high-energy charged particle beams; 3) The high-energy charged particle beam obtained in step 2) heats the compressed thermonuclear fuel under the guidance of the guiding magnetic field obtained in step 1) and the heating gold cone.

2. The method for fast ignition and efficient heating of laser fusion based on magnetic field guidance according to claim 1, characterized in that: The electromagnetic method described in step 1) is one of the following: interaction between nanosecond laser and capacitor coil target, pulsed strong magnetic field compressed and amplified by magnetic freezing effect, or inverse Faraday effect.

3. The method for fast ignition and efficient heating of laser fusion based on magnetic field guidance according to claim 1, characterized in that: The guiding magnetic field described in step 1) includes any one or more of the following features: A1) the guiding magnetic field is along the heating direction and covers the high-energy charged particle beam transport area; A2) The magnetic induction intensity of the guiding magnetic field is ≥ 1000 Tesla; A3) the duration of the guiding magnetic field is ≥ 10 picoseconds; A4) The radius of the area where the guiding magnetic field exists is 30-100 microns.

4. The laser fusion fast ignition and efficient heating method based on magnetic field guidance according to claim 1, characterized in that: The picosecond laser in step 2) includes any one or more of the following features: B1) The total energy of the picosecond laser is ≥ 20,000 joules; B2) The peak laser intensity of the picosecond laser is ≥ 1x10 20 W / cm2; B3) the laser pulse of the picosecond laser lasts for 3-20 picoseconds; B4) The laser focal spot diameter of the picosecond laser is ≤50 μm.

5. The method for fast ignition and efficient heating of laser fusion based on magnetic field guidance according to claim 1, characterized in that: The charged particles in the high-energy charged particle beam in step 2) are selected from one or more of fast electrons, protons or heavy ions.

6. The method for fast ignition and efficient heating of laser fusion based on magnetic field guidance according to claim 1, characterized in that: The other substances in step 2) are selected from one or more of metal films, crystal films, and polymer films.

7. The laser fusion fast ignition and efficient heating method based on magnetic field guidance according to claim 1, characterized in that: The heating gold cone described in step 2) or step 3) includes any one or more of the following features: C1) the opening angle of the heating gold cone is 50-80°; C2) The bottom of the heated gold cone is sealed, and the bottom radius is 10-30 microns.

8. The laser fusion fast ignition and efficient heating method based on magnetic field guidance as claimed in claim 1, characterized in that: In step 3), the distance between the heating gold cone and the compressed thermonuclear fuel is 30-100 microns.

9. The method for fast ignition and efficient heating of laser fusion based on magnetic field guidance according to claim 1, characterized in that: Step 3) heating the compressed thermonuclear fuel to 5-12 keV.

10. A laser fusion fast ignition and efficient heating system based on magnetic field guidance for implementing the method according to any one of claims 1 to 9, characterized in that: include: A nanosecond laser light source (1) and a capacitor coil target (2), wherein a nanosecond laser beam emitted from the nanosecond laser light source (1) is focused on the capacitor coil target (2) to generate a guiding magnetic field along a heating direction and covering a transport region of the high-energy charged particle beam; A picosecond laser light source (3) and a heating gold cone (4); a picosecond laser beam emitted from the picosecond laser light source (3) targets the heating gold cone (4), interacts with the heating gold cone (4) and / or other substances to form a high-energy charged particle beam, and, under the guidance of the heating gold cone (4) and a guiding magnetic field, targets and heats the compressed thermonuclear fuel (5); and the other substances are arranged inside the heating gold cone (4).

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