Plasma technology temperature and quasi-electrical neutrality

Plasma technology Plasma temperature and quasi-electrical neutrality:

Plasma temperature:

In general, substances can only be described in terms of a certain temperature T at thermodynamic equilibrium. Temperature is a measure of the average translational kinetic energy of microscopic particles within a substance. The relationship between the average translational kinetic energy of particles and the thermal equilibrium temperature can be described below:

1/2*mv²=2/3kT²

Where, m is the mass of the particle (kg); V is the RMS velocity (m/s); K is boltzmann's constant (1.380 6505×10^ -23J/k).

Plasma technology The macro temperature of plasma depends on the temperature of heavy particles. Te, Ti and Tg are used to represent the temperature of electrons, ions and neutral particles respectively. According to the plasma temperature of plasma technology, the plasma can be divided into high temperature plasma and low temperature plasma, and the low temperature plasma can be divided into hot plasma and cold plasma.

Plasma technology High temperature plasma means that the temperature of all particles in the system is basically the same, namely Tg=Ti=Tg=... = 10 ^ 6 ~ 8 K (10 ^ 2 ~ 4 ev) : low temperature plasma temperature of thermal plasma particles, namely Tg ≈= Ti ≈= Te, 5000 K < Tg < 20000 K (0.5 ~ 2 eV), cold plasma electron temperature in the far high other particles (ions and neutral atoms or molecules, etc.) temperature, namely the Te > > Ti ≈= Tg, other particles Tg temperature of 100 K < Tg < 1000 K, and electron temperature Te is usually greater than 10 ^ 4 K (sometimes heat plasma temperature is higher).

Quasielectric neutrality of plasma:

Plasma technology Plasma can be electrically neutral only at specific spatial and temporal scales. However, due to the interference of internal particle thermal motion and external electric field, partial charge separation may occur in the plasma, and the electric neutral condition is destroyed. However, the deviation is limited by time and space. Once the deviation occurs, the coulomb force interaction between the charges makes the neutral return as soon as possible. Because the deviation quantity |Ni-Nel<<Ne. Such "deviations" and "recoveries" are limited in space and time and are usually expressed by debye lengths and plasma cycles.