A new type of multipulse generator is proposed for the generation of high power pulses with an extremely short interpulse repetition interval. In this system, an air-core step-up transformer is used with a magnetic switch and a pulse forming line, which is charged in the double-resonance mode. Numerical simulations of this system have shown that 600 kV, 56 ns pulses, matched to a 20 /spl Omega/ impedance can be produced with a minimum pulse separation of 2.7 /spl mu/s. A small system was constructed to demonstrate the production of double pulses experimentally. The system contains two first stage capacitors of 150 nF each, a 1:15 air-core step-up transformer, a magnetic switch using cobalt based material, a second stage capacitor of 1.6 nF, and an 80 /spl Omega/ load. Double-pulses 100 ns wide, peak voltages of 85 kV (first pulse) and 90 kV (second pulse) have been successfully generated with an interval of 3.75 /spl mu/s between pulses, when the first stage capacitors were charged to 14 kV (for the first pulse) and 17 kV (for the second pulse).