Preliminary microwave-shock-produced plasma interaction experiments at high microwave power levels are reported that can result in the formation of a second plasma. A circular 2-in. ID shock tube waveguide is used to produce helium driven xenon and krypton plasmas at initial temperatures of 7,000-12,000 un. Concent 85% K and densities of st run. Concent 1017 cm-3. The onrushing shock-produced plasma is axially irradiated with X band microwaves (8.35 kMc/sec). The experiments described are for Mach 9 shocks in 1.0 mm Hg of xenon and krypton. When the irradiating X band microwave power is above some critical value for any given plasma, an r-f generated plasma detaches from the shock front and rapidly proceeds down the tube toward the r-f source, shielding the shock front from further irradiation.