What is plasma
What is plasma:
Plasma is an ionized gaseous substance composed of atoms deprived of some electrons and positive and negative ions generated after ionization of atomic groups. It is a macroscopic electroneutral ionized gas with a scale larger than Debby's length. Its motion is mainly controlled by electromagnetic force and shows significant collective behavior. It is widespread in the universe and is often seen as the fourth state in which matter exists apart from solid, liquid and gas. Plasma is a good conductor of electricity, and it can be captured, moved, and accelerated using a clever magnetic field. The development of plasma physics provides new technologies and processes for the further development of materials, energy, information, environmental space, space physics, geophysics and other sciences.
A plasma is a fourth state of matter different from solids, liquids and gases. Matter is made up of molecules, which are made up of atoms, which are made up of a positively charged nucleus and the negatively charged electrons surrounding it. When heated to a high enough temperature or for other reasons, the outer electrons break free from the nucleus and become free electrons, just like a student running to the playground after class. The electrons leave the nucleus, a process called ionization. At this time, the matter will become a positive nucleus and negative electrons composed of a uniform "paste", so people jokingly called it plasma, plasma, the total amount of positive and negative charges in the plasma is equal, so it is approximately neutral, so called plasma.
The seemingly "mysterious" plasma is actually a common material in the universe. It is found in the sun, stars and lightning, and accounts for 99 percent of the entire universe. In the 21st century, people have mastered and used electric and magnetic field generation to control plasma. Common plasma is high temperature ionized gas, such as arc, neon lights and fluorescent lights in the gas, such as lightning, aurora, etc. The electron gas in the metal and the carrier in the semiconductor and the electrolyte solution can also be regarded as plasma. On earth, there are far fewer plasma materials than solid, liquid, or gaseous materials. In the universe, plasma is the main form of matter existence, accounting for more than 99% of the total matter in the universe, such as stars (including the sun), interstellar matter and the ionosphere around the Earth, etc., are plasma. In order to study the generation and properties of plasma to clarify the movement law of plasma in nature and use it for human service, magnetohydrodynamic and plasma dynamics have been formed in the past 30 or 40 years under the impetus of astrophysics, space physics, especially nuclear fusion research.
Plasma is composed of a collection of ions, electrons and unionized neutral particles in a neutral state of matter. Plasmas can be divided into two types: high temperature and low temperature plasmas. Plasma temperature is respectively expressed by electron temperature and ion temperature, which are equal to each other and called high-temperature plasma. The difference is called a low temperature plasma. Low temperature plasma is widely used in many kinds
Production area. For example: plasma TV, baby diaper surface waterproof coating, increase beer bottle barrier. What is more important is the instant application of computer chips to make the Internet era a reality.
High-temperature plasmas occur only when the temperature is high enough. Stars constantly emit this plasma, which makes up 99% of the universe. A cryogenic plasma is a plasma that occurs at room temperature (although electrons are very hot). Low temperature plasma can be used for surface treatment such as oxidation, denaturation, or precipitation coating on organic and inorganic materials.
Plasma is a form of matter composed mainly of free electrons and charged ions. It is widely found in the universe and is often regarded as the fourth state of matter. It is called Plasma state, or "supergas", or "Plasma". Plasma has high conductivity and strong coupling effect with electromagnetic field. Plasma was discovered by Crooks in 1879, and in 1928 the American scientists Irving Langmuir and Tonks first introduced the term 'plasma' to physics to describe the form of matter in gas discharge tubes . Strictly speaking, a plasma is a gas cluster with high energy and kinetic energy. The total charge of the plasma is still neutral. By high energy of electric field or magnetic field, the electrons in the outer layer are shot out.
A plasma is the fourth state of matter, an ionized "gas," which exhibits a highly excited unstable state consisting of ions (with different symbols and charges), electrons, atoms and molecules. In fact, the plasma phenomenon is not new. In nature, hot flames, brilliant lightning, and brilliant auroras are all the result of plasma action. For the universe as a whole, more than 99.9% of matter exists in plasma, such as stars and interplanetary space. Plasma can be produced by artificial methods, such as nuclear fusion, nuclear fission, glow discharge and various discharges. The inner structure of a molecule or atom consists mainly of electrons and nuclei. In general, the relationship between electrons and nuclei is relatively fixed in the first three forms of the above substances, that is, electrons exist in different energy levels around the nuclear field, and their potential energy or kinetic energy is not large.
When the temperature of ordinary gas rises, the thermal motion of gas particles intensifies, resulting in strong collisions between the particles, and the electrons in a large number of atoms or molecules are knocked off. When the temperature is as high as 1 million to 100 million kelvin, all gas atoms ionize. The total negative charge of the ionized free electron is equal to the total positive charge of the positive ion. This highly ionized, macroscopically neutral gas is called a plasma.
Plasma is different from ordinary gas, which is composed of molecules, and the interaction force between molecules is a short-range force. Only when molecules collide, the interaction force between molecules has obvious effect, which is described theoretically by molecular motion theory. In plasma, the coulomb force between charged particles is a long-range force, and the effect of coulomb force far exceeds the effect of local short-range collision that can occur with charged particles. When charged particles move in plasma, they can cause local concentration of positive or negative charges, generating electric fields. The charge's directional motion causes the current and creates the magnetic field. Electric and magnetic fields affect the motion of other charged particles and are accompanied by extremely strong heat radiation and heat conduction. Plasma can be constrained by magnetic field to do rotation motion, etc. These properties of a plasma make it different from ordinary gases and are called the fourth state of matter.
Plasma is the primary normal state of matter in the universe. Space research, space development, as well as satellite, space, energy and other new technologies will enter a new era with the research of plasma.