The interaction with an external magnetic field modifies the variation of t
he shock wave configuration in a pure inert gas plasma at the entrance of a
supersonic diffuser. The phenomenon was studied using an experimental setu
p based on a shock tube with a flat nozzle and the model supersonic diffuse
r. The experiments were conducted in krypton, for the shock wave Mach numbe
r in the shock tube M = 7.8 and the Mach number at the nozzle exit M = 4.2.
The gasodynamic discontinuities and their structural variations induced by
the magnetic induction changes were by visualized by the schlieren method
and by photography of the intrinsic emission accompanying the process. Thre
e regions of the MHD interaction affecting the shock wave configuration in
the gas flow were revealed. (C) 2001 MAIK "Nauka/Interperiodica".