The electron distribution function in anisotropic plasma has been studied by probe method and Hanle magnetic polarization method. Moments of the anisotropic electron distribution function were measured in helium plasma - beam discharge, the rate constant of alignment decay for helium atoms in the 41D2 state as a result of collisions with charged particles was determined. A new method for diagnosing the anisotropic properties of inaccessible plasma objects has been experimentally tested; electron distribution functions, the degree of electron pressure anisotropy, and the alignment cross section of the total angular momentum of excited helium atoms in electron collisions have been measured. The advantage of the new method is the direct measurement of anisotropic parameters of inaccessible plasmas, the estimation of which was previously carried out only theoretically.
A method for recovering the full electron velocity distribution function and its angular components in a plasma with an arbitrary degree of anisotropy has been developed. The method is based on the measurement of the second derivative of the probe current with respect to the potential for different orientations of a flat one-sided probe with respect to the plasma symmetry axis. The optimal angles of the probe orientation are determined and the number of probe orientations necessary to recover the angular components of the electron velocity distribution of a given rank is estimated. The operability of the proposed method for determining the electron velocity distribution in a plasma with an arbitrary degree of anisotropy is demonstrated in a model experiment.
The kinetic equation for the motion of ions in the intrinsic gas is solved. It is shown that the ion velocity distribution differs significantly from the equilibrium (Maxwellian) distribution. The probe method was used to study the ion velocity distribution function in a low-temperature helium plasma.
