New possibilities for a cylindrical probe in gas-discharge plasma

In this work, the probe method of plasma diagnostics is further developed. It is shown that a cylindrical probe, by virtue of its geometry, permits one to reconstruct only even components $f_{2j}$ of the electron velocity distribution function (EVDF). To solve this problem, the method of nonequilibrium plasma diagnostics has been developed. It allows one to reconstruct the full EVDF and record diagrams of directed electron motion using a cylindrical probe. This method was tested in helium plasma of low-voltage beam discharge (LBD). The full distribution function has been determined and polar diagrams of directed electron motion in plasma have been constructed. The accuracy of the method is verified by comparison of the experimental data with the results of independent measurements by a flat one-sided probe, as well as with the results of numerical simulation.