Anisotropic temperature of charged particles in a variable electric field (Q2380202)

Time dependence of longitudinal and transverse temperatures in a completely ionized plasma immersed in a variable uniform electric field is analyzed by solving the equation of gas dynamics based on a bi-Maxwellian distribution. For a variable electric field, the degree of anisotropy \(X\) is negative and makes some hundredth parts, provided that the directed velocity of the charged particles is much smaller than the thermal one. For a constant magnetic field, \(X>0\) possibly reaches several unities. The setting time of transverse temperature is almost twice that of the longitudinal temperature. For a variable field, the parallel and perpendicular changes in time of the temperatures can have even different signs at the same point in time. Calculations show that the second moments \(I_{aa}\) of the Coulomb plasma are 16 times less than the lab, irrespective of the direction, if \(m_a\ll m_b\). The difference of the temperatures \(T_\perp\) and \(T_{II}\) is and additional source of thermal noise, described by the Nyquist formula. The results obtained can be used in the study of the initial formation of hot charge carriers, as F. G. Bass, Yu. G. Gurevich and V. Denis and Yu. Pohzela have already shown, and may be used in plasma diagnostics, too. However, the appearance of temperature and velocity gradients in the distribution function may restrict the application and the scope of the conclusions.