In summary: Hi,Is it physically possible at all to have MB distribution for an electric discharge in the gas (not raising the temperature), and it is similar to the figure above (peaks at 75 keV and ends at 150...)?Yes, it is physically possible to have an MB distribution.
As I said, that's the Hall effect (in the limit where the conductivity of the plasma is very large, i.e., ##\sigma \rightarrow \infty##, you have ##v=E/B##, because ##\vec{E}+\vec{v} \times \vec{B} \stackrel{!}{=}0## in this limit.