阅读说明：本技术 一种新型高效低膨胀的黑腔构型 (Novel high-efficiency low-expansion black cavity structure ) 是由 江少恩 景龙飞 张璐 况龙钰 李三伟 黎航 林雉伟 郑建华 李丽灵 于 2021-08-09 设计创作，主要内容包括：本发明公开了一种新型高效低膨胀的黑腔构型,包括本体,所述本体的内部设置有腔体,所述本体设置有上入射口,所述上入射口为入射激光提供让位空间；所述腔体呈橄榄球型结构；所述本体设置有环形的上凹槽,所述上凹槽的内壁为弧形结构；激光经由所述上入射口进入所述腔体内,并在所述上凹槽的内壁反射后,激活设置在所述腔体内的靶丸；本申请旨在提供一种新型高效低膨胀的黑腔构型,能够提升黑腔靶丸能量耦合效率,同时,改善内环激光传输,产生高温高品质的辐射源,为激光间接驱动惯性约束聚变点火腔型设计提供新的思路。(The invention discloses a novel high-efficiency low-expansion black cavity structure which comprises a body, wherein a cavity is arranged in the body, the body is provided with an upper incident port, and the upper incident port provides a abdicating space for incident laser; the cavity is of a football-shaped structure; the body is provided with an annular upper groove, and the inner wall of the upper groove is of an arc-shaped structure; laser enters the cavity through the upper incident port and is reflected on the inner wall of the upper groove, and then a target pill arranged in the cavity is activated; the utility model aims at providing a black chamber configuration of novel high-efficient low inflation can promote black chamber target pellet energy coupling efficiency, simultaneously, improves inner ring laser transmission, produces the high-temperature high-quality radiation source, provides new thinking for laser indirect drive inertial confinement fusion ignition chamber type design.)

1. A novel high-efficiency low-expansion black cavity structure comprises a body and is characterized in that a cavity is arranged inside the body, the body is provided with an upper incident port, and the upper incident port provides a yielding space for incident laser;

the cavity is of a football-shaped structure; the body is provided with an annular upper groove, and the inner wall of the upper groove is of an arc-shaped structure;

laser enters the cavity through the upper incident port and activates the target pellets arranged in the cavity after being reflected by the inner wall of the upper groove.

2. A novel black cavity configuration with high efficiency and low expansion as claimed in claim 1, wherein the inner wall of said upper groove is toroidal.

3. A novel highly efficient low expansion black cavity configuration as claimed in claim 2, wherein the arc α of the upper part of said upper groove is smaller than the arc β of the lower part of said upper groove.

4. A novel black cavity configuration with high efficiency and low expansion as claimed in claim 1, wherein said body is provided with a lower injection port, said lower injection port providing a space for incident laser to give way.

5. A novel black cavity structure with high efficiency and low expansion as claimed in claim 4, wherein the body is provided with an annular lower groove, the upper groove and the lower groove are symmetrically distributed at the upper end and the lower end of the body, and the inner wall of the lower groove is of an arc structure;

laser enters the cavity through the lower injection port and is reflected on the inner wall of the lower groove to activate the target pellets in the cavity.

6. A novel black cavity configuration with high efficiency and low expansion as claimed in claim 5, wherein the inner wall of said lower groove is toroidal.

7. The new high efficiency low expansion black cavity configuration of claim 6, wherein the arc of the lower portion of said upper groove is less than the arc of the upper portion of said upper groove.

Technical Field

The invention relates to the field of laser fusion black cavities, in particular to a novel high-efficiency low-expansion black cavity structure.

Background

The use of the huge clean energy released by controlled thermonuclear fusion to solve energy problems is an ideal that has been pursued by mankind. Laser indirect drive Inertial Confinement Fusion (ICF) is one of the controlled thermonuclear Fusion modes, laser energy is converted into X rays by using a black cavity, and a target pill filled with Fusion fuel is driven by the ablation of the X rays to generate implosion compression and thermonuclear ignition combustion, so that Fusion energy is released. Through more than ten years of attack and customs research, although milestones that fuel gain exceeds 1 and is gradually close to a 'combustion plasma' state (namely fusion is maintained by heat emitted by reaction itself instead of input laser energy) and the like are obtained, a traditional ignition black cavity still has a plurality of distances from an ignition target. The reason for this is that the traditional cylindrical black cavity has two serious bottleneck problems: 1) the black cavity target pellet has insufficient energy coupling efficiency (only about 10 percent), so that the target pellet is insufficiently driven, the hot spot surface density is lower than an ignition design value, alpha particles are difficult to be restrained from maintaining self-sustaining heating and combustion, and the black cavity parameter optimization space is limited; 2) the outer ring gold bubble plasma is expanded too fast, the laser energy of the inner ring is absorbed by the inner ring up to 44.8%, so that the inner ring is difficult to transport to the preset position in the middle of the black cavity, the quality of a radiation source is not high, the driving symmetry of a target pill in the later period is difficult to regulate and control, and the performance of the black cavity is limited to be further improved. Researches show that the energy coupling efficiency of the black cavity target pill can be improved by three times through the local shaping design of the black cavity, or the absorption share of the laser energy of the inner ring by the outer ring gold bubble is reduced to 5.9%. At present, researchers in the countries of the United states, France, China and the like who build large-scale laser devices vigorously carry out the design work of black cavity configurations, improve the performance of the black cavity, and gradually step towards the ignition target. As reported by Science, 11 months 2020, the National Ignition Facility (NIF) is testing black cavities of different shapes in order to better couple energy to the target pellet. The black cavity configuration is optimally designed, the bottleneck problem of the existing cavity is solved, the ignition margin is improved under the condition of limited output energy of the laser, the parameter range of the ignition target design is expanded, the ignition under the condition of higher gain or lower energy is realized, and the method has important research significance.

Disclosure of Invention

The invention aims to provide a novel high-efficiency low-expansion black cavity structure, which can improve the energy coupling efficiency of a black cavity target pellet, improve the laser transmission of an inner ring, generate a high-temperature high-quality radiation source and provide a new idea for designing a laser indirect drive inertial confinement fusion ignition cavity.

In order to achieve the purpose, the invention adopts the following technical scheme: a novel high-efficiency low-expansion black cavity structure comprises a body, wherein a cavity is arranged inside the body, the body is provided with an upper incident port, and the upper incident port provides a yielding space for incident laser; the cavity is of a football-shaped structure; the body is provided with an annular upper groove, and the inner wall of the upper groove is of an arc-shaped structure; laser enters the cavity through the upper incident port and activates the target pellets arranged in the cavity after being reflected by the inner wall of the upper groove.

Preferably, the inner wall of the upper groove is a toroidal structure.

Preferably, the arc α of the upper portion of the upper groove is smaller than the arc β of the lower portion of the upper groove.

Preferably, the body is provided with a lower injection port, and the lower injection port provides a yielding space for the incident laser.

Preferably, the body is provided with an annular lower groove, the upper groove and the lower groove are symmetrically distributed at the upper end and the lower end of the body, and the inner wall of the lower groove is of an arc structure; laser enters the cavity through the lower injection port and is reflected on the inner wall of the lower groove to activate the target pellets in the cavity.

Preferably, the inner wall of the lower groove is a toroidal structure.

Preferably, the radian of the lower part of the upper groove is smaller than the radian of the upper part of the upper groove.

The technical scheme of the invention has the beneficial effects that: the method adopts a non-uniform rational B spline method, realizes the parameterized modeling and characterization of the hidden free-form surface of the black cavity by adjusting control points and weights, optimizes the configuration of the black cavity, reduces the cavity wall area and improves the coupling efficiency; meanwhile, the cavity type can simultaneously avoid the bottleneck problem faced by the current black cavity configuration, shows excellent comprehensive black cavity performance, and provides a new idea for the cavity type design of a high-temperature high-quality radiation source. The advantage of current chamber type can be compromise to this application, promotes black chamber target pellet energy coupling efficiency, improves inner ring laser transmission, produces the high-temperature high-quality radiation source, provides new thinking for laser indirect drive inertial confinement fusion ignition chamber type design.

Drawings

FIG. 1 is a schematic block diagram of one embodiment of the present invention;

fig. 2 is a schematic cross-sectional structure of one embodiment of the present invention.

Wherein: the solar cell comprises a body 1, a cavity 2, an upper incident port 3, an upper groove 4, a lower incident port 5 and a lower groove 6.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Furthermore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features for distinguishing between descriptive features, non-sequential, non-trivial and non-trivial.

In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 and 2, the novel efficient low-expansion black cavity structure comprises a body 1, wherein a cavity 2 is arranged inside the body 1, the body 1 is provided with an upper incident port 3, and the upper incident port 3 provides a yielding space for incident laser; the cavity 2 is of a football-shaped structure; the body 1 is provided with an annular upper groove 4, and the inner wall of the upper groove 4 is of an arc-shaped structure; laser enters the cavity 2 through the upper incident port 3, and after being reflected by the inner wall of the upper groove 4, the laser activates target pellets arranged in the cavity 2.

Cavity 2 adopts football type structure in this application, utilizes the configuration of "big both ends are little in the middle of," reduces black chamber inner wall surface area, reduces chamber wall energy leakage, improves black chamber radiation source temperature, and then promotes black chamber target pellet energy coupling efficiency.

Set up groove 4 in this application, increase groove structure design at the outer loop laser impact point department in traditional column type black chamber, delay outer loop gold bubble plasma and get into the time of inner ring laser channel, reduce the gold bubble and to the absorption share of inner ring laser energy, improve the transmission of inner ring laser, make inner ring laser energy deposit smoothly to black chamber middle part and predetermine the position, maintain laser pulse later stage target pellet drive symmetry.

The method adopts a non-uniform rational B spline method, realizes the parameterized modeling and characterization of the hidden free-form surface of the black cavity by adjusting control points and weights, optimizes the configuration of the black cavity, reduces the cavity wall area and improves the coupling efficiency; meanwhile, the cavity type can simultaneously avoid the bottleneck problem faced by the current black cavity configuration, shows excellent comprehensive black cavity performance, and provides a new idea for the cavity type design of a high-temperature high-quality radiation source. The advantage of current chamber type can be compromise to this application, promotes black chamber target pellet energy coupling efficiency, improves inner ring laser transmission, produces the high-temperature high-quality radiation source, provides new thinking for laser indirect drive inertial confinement fusion ignition chamber type design.

Preferably, the inner wall of the upper groove 4 is a toroidal structure.

Specifically, the arc α of the upper portion of the upper groove 4 is smaller than the arc β of the lower portion of the upper groove 4.

The geometrical configuration design of the toroidal dome is adopted, so that the time for the outer ring gold bubble to enter the inner ring laser channel is delayed, the inner ring laser transmission is improved, the target pill driving symmetry is maintained, and the quality of a radiation source is improved.

Preferably, the body 1 is provided with a lower injection port 5, and the lower injection port 5 provides a yielding space for the incident laser.

Specifically, the body 1 is provided with an annular lower groove 6, the upper groove 4 and the lower groove 6 are symmetrically distributed at the upper end and the lower end of the body 1, and the inner wall of the lower groove 6 is of an arc structure;

the laser enters the cavity 2 through the lower injection port 5 and activates the target pellet arranged in the cavity 2 after being reflected by the inner wall of the lower groove 6.

The invention mainly aims at the condition that the existing laser device adopts a double-end injection arrangement design, and improves the energy coupling efficiency of the black cavity target pill. If the laser device adopts a multi-end single-ring injection arrangement design and the black cavity configuration adopts a football cavity design (such as a triaxial shaping football cavity), the blocking problem of the outer ring gold bubble to the inner ring laser transmission can be avoided, the coupling efficiency is improved, and the risk is reduced, and the invention can also be completed.

Preferably, the inner wall of the lower groove 6 is a toroidal structure.

Specifically, the radian of the lower portion of the upper groove 4 is smaller than the radian of the upper portion of the upper groove 4.

The invention adopts the geometric configuration design of the toroidal dome, delays the time for the outer ring gold bubble to enter the inner ring laser channel, improves the transmission and energy deposition of the inner ring laser, maintains the target pill driving symmetry and improves the black cavity performance.

Based on the initial analysis of the black cavity configurations carried out by a hundred thousand Joule laser device in China, the black cavity configurations comprise: the cylindrical black cavity and the I-shaped cavity are added, the cylindrical black cavity analysis is for comparison, the I-shaped cavity and the novel black cavity configuration of the application are compared in a key mode, and the performance of each black cavity is evaluated according to indexes such as driving asymmetry, coupling efficiency and plasma filling:

driving asymmetry:

the root mean square RMS of the driving asymmetry of the three cavity type target pills is less than 4 percent, and the symmetry of the novel black cavity is equivalent to that of the column type black cavity and is superior to that of the I cavity. It should be noted that the new black cavity has not been optimized for parameters such as cavity length, dome structure, etc.

Coupling efficiency:

the coupling efficiency is defined as the fraction of the X-ray energy absorbed by the target pellet in the black cavity. The I-shaped cavity groove structure increases the cavity wall area, so that the cavity wall leakage share is increased, the radiation temperature of the black cavity is reduced by 5eV relative to the columnar black cavity, and the energy coupling efficiency is reduced from 12.47% to 11.15%; due to the unique configuration of the novel black cavity, the cavity wall leakage share is lower than 50%, the coupling efficiency is improved by 21% relative to the I-shaped cavity, and the radiation temperature of the black cavity is relatively improved by about 4.8% (the radiation flow is relatively improved by about 19%).

Plasma filling:

the plasma fill time indirectly assesses the laser plasma instability in the black cavity. As can be seen from Table 1, the plasma filling effect of the novel black cavity is close to that of the traditional column-shaped black cavity and is superior to that of the 'I' cavity.

The performance of the three cavity types is compared as shown in the following table:

TABLE 1 comparison of Black Cavity Performance for each Cavity type

Wherein: the fixed target pellet diameter, the diameter of the middle part of the black cavity and the target pellet diameter CCR, the length of the black cavity, the laser injection hole diameter LEH and other parameters are the same, 48 laser beams are injected into the black cavity according to the inner ring and the outer ring, the laser impact point of the outer ring is positioned in the groove or the dome structure, the single-path laser power is 3kJ/3ns, the tau Cyl represents the column-shaped black cavity plasma filling time, and the filling time is normalized according to the tau Cyl.

The football-shaped structure is independently adopted, the outer ring gold bubble is closer to the inner ring laser channel in the football-shaped cavity 2, for example, a hundred thousand Joule laser device in China is taken as an example, the distance between the outer ring gold bubble and the inner ring laser of the football-shaped cavity 2 is reduced by 15 percent relative to a cylindrical black cavity, the interaction risk of the outer ring gold bubble and the inner ring laser is larger under the time scale of ignition pulse, the inner ring laser is difficult to transmit to the preset position in the middle of the black cavity, the driving symmetry of a target pill is difficult to predict and regulate, and the quality of a radiation source is difficult to meet the ignition requirement.

The I-shaped cavity structure is independently adopted, the groove structure design of the I-shaped cavity additionally increases the cavity wall area, for example, a hundred thousand Joule laser device in China, the cavity wall area of the I-shaped cavity is additionally increased by 21 percent relative to a columnar black cavity, the cavity wall energy leakage is aggravated, and the energy coupling efficiency of a black cavity target pellet is further reduced.

The laser indirect drive inertial confinement fusion adopting the traditional columnar black cavity has not been successfully ignited, and has two bottleneck problems of insufficient energy coupling efficiency of a black cavity target pellet, too fast expansion of an outer ring golden bubble to block laser transmission of an inner ring and the like; the groove structure design of the I-shaped cavity additionally increases the cavity wall area, aggravates the cavity wall leakage and further reduces the coupling efficiency.

The invention provides a novel high-efficiency low-expansion black cavity structure, which can take the advantages of a football cavity and an I cavity into consideration, improve the energy coupling efficiency of a black cavity target pellet, improve the inner ring laser transmission, generate a high-temperature high-quality radiation source and provide a new idea for designing a laser indirect drive inertial confinement fusion ignition cavity. By adopting a non-uniform rational B spline method and adjusting control points and weights, the hidden free-form surface parametric modeling and characterization of the black cavity are realized, the black cavity configuration is optimized, the cavity wall area is reduced, and the coupling efficiency is improved; meanwhile, the geometrical configuration design of the toroidal dome is adopted, so that the time for the outer ring gold bubble to enter the inner ring laser channel is delayed, the inner ring laser transmission is improved, and the target pill driving symmetry is maintained. The novel black cavity structure provided by the invention can simultaneously avoid the bottleneck problem of the current black cavity, shows excellent comprehensive black cavity performance and provides a new idea for designing the cavity of the high-temperature high-quality radiation source.

The invention utilizes the football configuration to reduce the wall area of the black cavity and reduce the energy loss of the cavity wall, thereby improving the energy coupling efficiency of the black cavity target pellet and enhancing the target pellet driving; meanwhile, the geometrical configuration design of the toroidal dome is adopted, so that the time for the outer ring gold bubble to enter the inner ring laser channel is delayed, the transmission and energy deposition of the inner ring laser are improved, the target pill driving symmetry is maintained, and the black cavity performance is improved. The cavity type can simultaneously avoid the bottleneck problem faced by the current black cavity configuration, shows excellent comprehensive black cavity performance, and provides a new idea for the cavity type design of a high-temperature high-quality radiation source.

In the description herein, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.