Summary form only given, as follows. Atmospheric pressure plasmas have gained much interest because of their possible uses as plasma reactors, as light sources, for thin film deposition or surface modification, and as plasma ramparts. For plasma ramparts the electron density needs to be on the order of 10/sup 13/ cm/sup -3/ at a gas temperature below 2000 K. At equilibrium conditions, where the electron energy distribution (EEDF) is fully determined by the reduced electric field, E/N, the power required to sustain such plasmas is on the order of 5 kW/cm/sup 3/. However, by shifting the EEDF temporarily (on a time scale of less than the time constant for glow-to-arc transition) towards higher energies, and consequently increase the rate coefficient for ionization it is possible to reduce the average sustaining power considerably. This power savings effect has been demonstrated with a single 10 ns pulse applied to a DC glow in atmospheric pressure air. As a first step towards repetitive pulsed electric field operation, required to obtain a semi-DC plasma with high average electron density we have designed and constructed two types of dual pulse generators. Both utilize 10 /spl Omega/ pulse forming networks (PFN) in a strip line configuration with high-pressure spark gaps as switches. The first generator concept utilizes two pulse generators operated in parallel, which deliver the two subsequent pulses directly to the load. The trigger pulses for the two switches can be adjusted in time between 1 /spl mu/s and 10 ms. The second concept utilizes two PFNs, which are arranged in series. After the first PFN is discharged into the load through a high power switch, the second PFN will be discharged into the first one, which then acts as a regular transmission line. Pulse amplitudes of 13 kV have been reached, but amplitudes of up to 50 kV seem to be possible.