Numerical model of operation of the Langmuir probe under intermediate pressure

Summary form only given. The technique of Langmuir probes has been known for a long time. However, despite plenty of work devoted to calculation of current on a probe inserted into plasma, a theory does not exist at present which would permit calculation of the parameters of plasma at any size of probe and pressure of a working gas. There is no rigorous enough theory which would describe a probe under high gas pressure. As for intermediate pressure, there are no theories. The solution of the problem is in this case considerably complicated because of non-local dependence of density of charged particles on potential or electric field strength, that means the hydrodynamic approach is unusable and necessity of application of the kinetic theory. To fill in this gap the author has developed (on the basis of experimental researches) a numerical model of ion kinetics in a near-boundary layer of a Langmuir probe, inserted into a weakly-ionized gas-discharge plasma, in a range of intermediate pressure of a neutral gas (the length of free path of charged particles has the same order, as the size of a probe), as well as at any ratio between thickness of the layer of space charge and radius of the probe.