The configuration of a nonthermal plasma reactor strongly affects the rate of electron collision reactions. Experiments involving the decomposition of NO in N-2 were performed in a reactor in which the number of parallel reactor tubes varied from 1 to 10 at a constant pressure of 147.6 kPa and ambient temperature. A previously developed lumped model of the reactions accurately predicted the effects of varying the initial concentrations of NO (from 24 0 ppm to 593 ppm) and gas residence time (from 1.93 to 7.42 s). With an increasing number of parallel reactor tubes, the rate of electron collision reactions decreases because the energy input per unit reactor volume at unit time decreases, while the energy consumption per molecule of NO converted to N-2 and O-2 decreases due to electrical and geometric effects associated with the decreasing peak width of the discharge voltage pulses and increasing reactor capacitance. Therefore, increasing the number of parallel reactor tubes provides a viable scale-up method for constructing more efficient pulsed corona discharge reactors. (c) 2005 American Institute of Chemical Engineers.