Use of the Bohm’s formula and its analogues in probe diagnostics

Simple algorithms are developed to proceed the probe characteristics in a number of limiting regimes when the characteristic probe size, $r_p$, is relatively large $(r_p > 10^3r_{\text{D}})$. It relates both to steady plasmas and to movement with the directed velocity, $u$. We consider the cases of collision-free (the Knudsen number, $\rm Kn \gg 1$) and collisional $(\rm Kn \ll 1)$ plasmas. The majority of the proposed algorithms are tested in practice and confirm their reliability.