Plasma Physics Plasma Physics
Study plasma form and collective motion law, the discipline of plasma and electromagnetic fields and other morphological substances. Emerging branches of physics.
humans 'understanding of plasma, began in the 1970s' research on gas discharge pipes in the gas discharge pipe. In the 1970s, the basic concepts of plasma were established and the characteristics of time and space. In the early 1930s and 1950s, based on other discipline research methods, the basic theoretical framework and description method of plasma were created. At the same time, the scope of research was expanded from the laboratory's ionization gas to the ionization layer and some celestial bodies. gas.
has since since 1950s, under the promotion of controlling thermal nuclear fusion research and spatial technology , plasma physics has been fully developed and has become an independent branch of physics. During this period, the low -temperature plasma physical and process was developed on the basis of gas discharge and arc technology. At the end of the
0s of the 2010 century, in the field of basic industry, defense industry, and high -tech fields, low -temperature plasma was widely used, and promoted the mutual penetration of plasma physics and other physics disciplines and technical sciences. With the deepening of plasma physics research,
has gradually expanded: from traditional electrical neutral plasma to non -electrococcular plasma physics, from the plasma of the weak coupling to the strong coupling plasma; from purely pure Plasma expands to dust plasma, from linear phenomenon to non -linear phenomenon.
, in addition, the new progress of laser technology has promoted the research on the interaction between ultra -short pulse and strong laser and plasma. Research in these fields adds new vitality to plasma studies.
has experimental research, theoretical research, and particle simulation.
's experimental research and detection of experimental research and detection of natural plasma (plasma, space, and earth atmosphere) is usually performed on the earth surface or "space laboratory" on the surface of the earth or on the high -altitude aircraft and "Space Lab". And the visible light, radio, X -ray and other radiation they are emitted.
analyzes these measurement results with existing data and theories, so as to understand the phenomenon, essence, movement, institutions, and evolution of these natural plasma.
's experimental research on the artificial plasma (laboratory plasma) produced by artificially generates the required plasma for the required plasma and then measures the various parameters of the plasma.
comprehensively analyzes these measurement results with existing theories, inferring the behavior and nature of plasma, or establishing a new theory.
has the following theoretical descriptions:
① single particle track description method. It describes a single charged particle in the plasma, and changes in the track of motion under the action of the electric field or magnetic field. The track of
single particles can be simply determined with Newton's law and the initial conditions of the particles (spatial position and speed).
In the collision -free plasma (such as space plasma), the average free range of in the collision greatly exceeds the spatial scale of the plasma itself. Description of some observation results.
but the purpose of the orbit description is not to give the plasma behavior, but to discuss the zero level of zero levels when the interaction between particles is further discussed, that is, the starting point of theoretical analysis and discussing actual problems. The
single -particle track description method can give very intuitive physical images, and has played an important role in proposing and developing the concept of magnetic constraint fusion research.
② magnetic flow description method. The plasma is regarded as a conductive fluid without considering the differences between the motion of different particles. The behavior is described by fluid mechanics equation and electromagnetic equation.
magnetic description method can be used to describe macro behaviors of plasma, such as collective oscillation, macro balance, macro -stability, and various volatility of plasma.
③ Statistics description method. Plasma is a system composed of a large number of particles. The method of statistical physics can deeply reveal its movement rules, including describing the Flasov volatility of the Flasov in the collision -free plasma and the interaction of particles. Motor theory.
single -particle track description method and magnetic flow description method is similar to the approximate description method. The former does not consider the differences between different particles of movement, and the latter ignores the interaction between particles. The phenomenon of role cannot be revealed that the unstable instability caused by the particle system distribution function deviates from the balance state in the speed space.
statistical description method can strictly describe the interaction between waves and particles and some micro phenomena. Although the statistical description method is strict, mathematical processing is complicated, and physical images lack intuitiveness.
This method is to track the movement track of thousands of or even millions of particles to describe the plasma system, which can also give many physical quantities about waves and particles at the same time.
but a typical laboratory plasma (plasma in the vertical device) of plasma (plasma in a fusion device) is about/cubic meter. Although the density of space plasma is very sparse, the volume is huge (the scale is greater than or equal to thousands of kilometers). /Cube kilometers to calculate the number of particles. If
considers the orbits of these particles, the capacity of modern computers is far from enough.
If it is limited to studying certain types of plasma, you only need to examine a relatively small simulation system. Describe the behavior of plasma.
Basic content of Plasma Physics can be roughly divided into the behavior of a single -tape particle in the electromagnetic field, plasma balance, volatility and instability, relaxation and transportation, electromagnetic radiation and other aspects.
charged particles in the vertical direction of magnetic line are performed in the vertical direction of the magnetic force line (called a rotary or Lamore movement), and the charging particle in the direction of the magnetic force line also performs free movement. Therefore, the synthetic movement of the particles is to do spiral motion with the magnetic line as the axis as the axis. If the
is also used by other external forces, the particles will also exercise in the direction of the magnetic line and the power. This movement caused by external forces is called drift. If
external force If it is electric field force , gravity, force or broad power caused by magnetic field gradient or magnetic field curvature, the drift movement caused by them is called electric drifting, gravity drift, gradient drift and curvature drift. If the
magnetic field changes slowly with space and time, the kinetic energy of the particles in the direction of the magnetic line and the magnetic field strength (referred to as magnetic torque ) is a non -variable. These simple physical images above
are of great significance for the exploration of magnetic constraints in the controlling thermal nuclear fusion, the behavior of celestial plasma, and the understanding of magnetic sputtering principle.
plasma under certain conditions will be affected by its internal heat pressure, plus electromagnetic field and gravity. When these forces reach balance, the macro shape of the plasma and the value and spatial distribution of each parameter will no longer change over time. The plasma morphology and parameter and spatial distribution of the plasma during balance are the basis for discussing the behavior of plasma.
Plasma where plasma is in a balanced state is disturbed, and corresponding collective movements will be generated inside the plasma rest, causing this disturbance to other areas of the plasma. The disturbance of this spread is called plasma waves.If
does not change with time during the dissemination process, this wave is called a stable plasma wave, otherwise it is a damping wave or an unstable wave.
If during the spread, the disturbance amplitude is getting larger and larger, and the balance of the plasma can be destroyed, then this disturbance is referred to as unstable. The
disturbance method is different, and the types and attributes of fluctuations are different.
The disturbance of the heat pressure inside the ion plasma generates sound waves.
space charge is separated to generate static waves.
electromagnetic induction causes electromagnetic wave .
plasma temperature and uneven density space causes particle drift motion to stimulate various drift waves.
Frequency of magnetic force lines in plasma and frozen effects of plasma can produce various magnetic flow waves; the bending and uneven distribution of magnetic wires can also stimulate various drift waves.
and waves and waves will be coupled with more complex hybrid waves.
Plasma is unstable, which are roughly divided into two categories: macro -stability and micro instability.
plasma macro parameters (density, temperature, pressure, etc.) are uniform and free energy caused by the curvature of the magnetic line, which can produce macro instability. It is usually treated with fluid equations.
plasma velocity space in the speed distribution of the speed distribution in the speed distribution, deviating from Maxwell's speed distribution law, etc., will produce micro instability (also known as speed and space instability). It is usually treated with dynamic equations. Study unstable.
Electromagnetic waves can be divided into two categories: spontaneous radiation and exciting radiation.
spontaneous radiation includes black body radiation, line radiation, composite radiation, tadpole radiation, rotating radiation (also known as magnetic ravioli radiation), synchronous radiation, etc.
Most experimental plasma issued by spontaneous radiation, laser produced by plasma laser substances, and some electromagnetic radiation observed in the magnetic layer of the earth and several planets is severe radiation.
detects the radiation of plasma can get some parameters of the plasma.
plasma is called relaxation process. In the
uneven plasma, the charged particles diffuse from high -density areas to low -density areas. The heat is transmitted from a high temperature area to a low -temperature zone. The traditional theory of
believes that relaxation and transportation are caused by the Kulun elastic collision between the particles. It is usually treated with the theoretical of the collision, the characteristics of the characteristics of the relaxation (slow time, diffusion time, etc.) and various types of obtained. The transportation coefficient (diffusion coefficient, thermal conductivity, sticky coefficient, conductivity coefficient, etc.) is called classic.
If the geometric effect of the circular magnetic field on the phase -touch particle track movement is considered, the corresponding relaxation and transportation are called new classics. Various new classics are larger than the classics.
, in addition, the transport factor in many plasma (including space plasma and magnetic bunks) is 2 to 4 levels higher than the new classic. Exercise related.
plasma physics has formed the following branches that are related to each other and have relatively independent research directions.
control thermal nucleus polytable plasma physics is a experimental device that studies the real -thermal nuclear fusion reaction, as well as various physical problems involved in the plasma (also known as high -temperature plasma) in the future nuclear fusion reactor.
generally said that the research topic of controlling thermal nuclear fusion plasma physics is mainly concentrated. How to heat the reaction temperature of fuel plasma to hundreds of millions of degrees, and how to restrain high -temperature plasma with sufficient density. Make it sufficient nuclear reaction and other aspects.
control thermal nuclear fusion research began in the middle of the 20th century. In the late 20th century until the beginning of the 21st century, he was controlled by thermal nuclear fusion, and mainly focused on using the magnetic field to restrict the chief of the plasma (magnetic constraint), and the inertia of the plasma particles was used aspect. The physical problems involved in
are naturally the main research content of the controlled thermal nuclear fusion plasma physics.
daily space is the plasma system that is composed of Taiyang atmosphere, solar wind , earth magnetic layer and ionization .
Space Plasma Physics is a branch discipline that studies the physical process of plasma for plasma in this system. It is an intersection of plasma physics, space physics and solar physics.
has developed rapidly in recent years. The basic problem of plasma physics involved in the research of
in the frontier field of the Japanese and ground space (the energy transmission and coupling mechanism of the Japanese and ground system) is the re-connection of magnetic lines, wave-particles interaction and aggressive transportation, no collision, plasma, plasma, plasma Body heating and high -energy particles acceleration, spatial plasma turbulence, large -scale plasma flow, respectively, and magnetic fields and neutrophils.
Space Plasma Physics for aerospace safety and space applications, environmental monitoring and forecasts, radio communication, understanding of solar activity to cause changes in the ecological environment of the earth, long -term changes in the predictive atmosphere, and it is very important for various non -linearity phenomena of plasma to study plasma. Significance.
Plasma Astronomical Physics is a cross -disciplinary combination of celestial physics and plasma physics.
plasma plasma physics begins in the first half of the 20th century. The main research content is concentrated in the acceleration of cosmic particles, the radiation mechanism of celestial plasma, and unstable and related explosive images. Since the 1980s,
has mainly studied many non -linear phenomena of plasma plasma, the interaction of radiation and plasma, atomic and molecular process, particle acceleration mechanism in plasma plasma.
low -temperature plasma refers to part of the electric ionization gas generated by the temperature of hundreds of thousands of degrees in the laboratory and industrial equipment in the laboratory and industrial equipment.
According to its physical properties, low -temperature plasma can be divided into three categories: thermal plasma (near LAN thermodynamic balanced plasma), cold and other ions (non -balanced plasma), and burning plasma.
thermal plasma and cold ions have been widely used in the industry, so they are collectively called industrial plasma. Low -temperature plasma physics is the science of the production of part of the ionization gas, nature and movement law.
Low -temperature plasma components in the ionic plasma, in addition to electronics and ions (density at/ cubic centimeters ), there are a large number of neutral particles (atoms, molecules, free radical ). The components of the
particles and the interaction between them (including the process of participating in various multi -body collisions and photon ) are changed with the method and conditions of plasma.
has made low temperature plasma physics much more difficult to study the research of high -temperature plasma physics that is completely ionized.
Low -temperature plasma involves manufacturing, material surface treatment, modification, and film deposition of large -scale integrated circuits, including chemical production, gas discharge light sources (high, low pressure lighting), including ultra -fine powder and ultra -pure materials preparation, and In many applications such as gas laser, plasma display, and magnetic flow power generation, its research has very important practical significance.
has the application of controlling thermal nuclear fusion, space and celestial plasma, low -temperature plasma applications. Driven by research, the following new areas have become the forefronts and hotspots of plasma physics research.
non -neutral plasma refers to a single -type electrical particle (electron, ion) and neutral particles, and the overall non -electrical neutral plasma.
non -neutral plasma physics is a branch discipline that studies the theory of non -neutral plasma and experimental technology. It has penetrated the atoms and molecular physics, condensed state physics , new accelerator physical, free electronic laser physics, high power, high power Microwave physics and many other fields. The main content of
its research is: various macro and micro instability in plasma composed of pure electron or pure ions and its non -linear processes, the spread of strong stream beams and the constraints and transportation of its particles, cooling methods, refrigeration methods, refrigeration methods, cooling methods, cooling methods, cooling methods, cooling methods, cooling methods, cooling methods. The phase change from gesture to liquid and solid state (strong coupling interaction) and so on.
strong coupling (associated) Plasma is a plasma system that refers to the average interaction (bit energy) between particles and particle kinetic energy (called coupling coefficient). The coupling coefficient of common plasma is less than 1, so it is weak coupling.
uses laser as a driver's inertial restraint plasma, plasma generated by laser explosion substances, highly evolved substances inside the celestial body, and the electronic temperature when the electronic temperature drops to a very low. Pure ion plasma and dust particles have sufficient electric dust plasma, all of which are strong coupling plasma.
Strong coupling system is a complex multi -particle system. The two -body correlation function is not enough to study certain characteristics and requires knowledge about multi -body correlation functions. The theory of describing the dynamic related characteristics of this system needs to be established, and strong coupling plasma physics is in the development stage.
plasma system is essentially non -line. Two of the two non -linear research areas are unrelated non -linear phenomena (turbulent phenomena) and related non -linear structures.
plasma turbulence is a collective motion state of unprecedented phase characteristics composed of a large number of plasma -based models that interact with each other. It may be a mechanism that generates anomalous resistance, abnormal diffusion and abnormal heat -guided heat guidance. A related non -linear phenomenon refers to some non -linear processes closely related to phase information.
weak non -linear coherent phenomenon appears during the process of three waves, four -wave interaction and plasma echo. Strong non -linear similar behaviors often show the orderly structure of a long life, such as orphan, cavity, and vortex. The impact of this coherent structure on the nature of the ions and the relationship between the turbulence with the plasma is an important part of the physical research of nonlinear plasma.
studies the science of laser and plasma interaction. It is a disciplinary basis for laser nuclear fusion and nuclear weapon physical, X -ray laser, laser -driven particle accelerator.
's main research is:
① laser and fusion plasma interaction, laser and coronation region plasma interaction that appears in various laser plasma unstable and its effects on laser and polymerization target coupling.
② laser drive high -energy particle accelerator physics. The laser accelerator uses plasma as a medium, and the accelerated electric field can reach volt/meter, or even higher, which is several magnitude higher than the extreme acceleration field (volt/meter) of the linear accelerator. = 1 trillion electronic) super high energy.
mainly focuses on the mechanism of accelerated electric field, wave-wave-particle interaction processes, and the impact of various instability on the related acceleration process.
③ Ultra -short pulse strong laser interaction with plasma. This is an important area for research at the end of the 20th century.The development of
laser technology makes it possible to obtain pulse width to 50 to 1000 femtosecond (1 second = 1 trillion femtosecond), focusing power density to/ . Create a new field of cutting -edge research.
is stronger than the Kulun field inside the atom because of this strong light, so this research field is also called strong physics.
④ Experimental simulation of the process. Laser plasma produced by laser and target interaction has a mutually corresponding relationship with celestial plasma.
, such as , the laser of on the target causes the target substance to evaporate, icon and expand, which is the Star Wind and Super Novels of Star Wind with a higher expansion speed; The impact waves that are formed in the direction of the laser, corresponding to the shock wave of jet driver of the supernova; the strong coupling plasma produced by the thin metal target on the laser irradiated glass plate, corresponding to the inside of the sun, white dwarf , inside of the giant stars Strong coupling substances, etc.
Laser Plasma Plasma Physics or Laser Fusion Principles can correspond to the laws of celestial physical fitness, but the time and spatial scale of the two processes are extremely different. As long as the scale of the corresponding physical quantities of the two is proportional to the scale (this transformation is called the marking transformation), the physical process of the laser plasma can simulate the corresponding astronomical physical process. The label transformation between
HTML's strong laser plasma interaction between the interaction of strong laser plasma interactions and Super Novelty and supernova relics are a model of success.is developed with the development of space detection technology. In addition to the Sunwind, it is also in the solar wind, but also in the solar radio, toxoplasma, geo -region radiation, electrical double -layer, ground magnetic pulse, magnetic storm Wait for the existence of high -energy particles in the physical process. In the polytable plasma, there is a high -energy α particles generated by reactions.
The interaction between high -energy particles and background plasma can be changed, which can change the stable construction of the original wave mode or stimulate some new unstable models, affecting the in -depth research of plasma physics in high -energy component plasma physics, development, and development of plasma. Become an important area.
The main content is the effects of relaxation, acceleration, heating and radiation in high -energy particles in the background plasma, and the impact of background plasma balance, stability, etc.
mixed with electrical neutral solid particles in the plasma, the difference between the difference in the speed of electron and ion thermal motion, or due to the radiation of strong ultraviolet rays and external lasers, Hezheng electricity. When the amount of these dust particles is sufficient enough, the original collective effect of the plasma will change. At this time, the plasma is waiting to be called dust plasma.
dust particles are common in laboratory plasma and celestial plasma. Laboratory plasma Due to the particles, electrodes, or substrates bombarded by high -energy particles, and two working gases that have react in the plasma state, the solid particles that are gradually grown in the plasma state are the laboratory. plasma Dust Dust particles.
Skytimeter's fragments, meteorite particles, lunar throwing substances, and human "pollution" of space to form a source of dust in plasma plasma. In the
microelectronics industry (such as plasma etching, shooting coating and other processes), the impact of dust particles on the product is very serious. semiconductor material 's loss of 50 % of production is caused by pollution of dust particles during the production process.
laboratory dust plasma observed the self -organizational phenomenon of dust particles, forming a dusty plasma crystal, and the phenomenon of strong coupling (association) between particles. The
spacecraft's detection of Jupiter and Mars is true that their halo is composed of dust particles of various sizes of 10 nanometer to 1 meter.
The Coptisites of the solar system are distributed at 3 to 19 earth radius around the solar, and the dust particles with a scale of 2 to 10 microns are caused by the scattering or thermal radiation of the solar radiation.
people have more and more paid attention to the peculiar use of dust particles in laboratory plasma and celestial plasma. Dust plasma physics has become a very active research field in plasma physics at present.
plasma physics in 1879 British scientist W. Crux proposed the concept of material fourth state, it has developed into an important branch of physics. From the perspective of the overall research status of
, the research on the research on the physics and celestial plasma physics of nuclear fusion plasma (high -temperature plasma) is relatively mature, but there is still lack of research on low -temperature plasma physics, and some new research fields also It is constantly emerging, so it still needs to be further developed. Plasma physics has been continuously widely used in the fields of energy, national defense, communications, materials science, biology, and medicine.
Recommended Books
National Natural Science Foundation of China. Strategic Report of the Development of Natural Sciences: Plasma Physics. Beijing: Science Press , 1994.
is taken from: "China Encyclopedia (2nd Edition)" Volume 4, China Encyclopedia Press , 2009
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