Distribution of OH within silent discharge plasma reactors

Barrier discharges in humid air generate large quantities of OH and are well suited for the treatment of gas-based pollutants. In order to understand and optimize the formation and utilization of OH, we have imaged the spatial and temporal distribution of the OH radical with resolution of 40 /spl mu/m and 100 ns. Using a flowing mix of Ar/O/sub 2//H/sub 2/O (78.5/20/1.5), we have found that OH exists only within the 85-/spl mu/m radius channel formed by the transient microdischarge. At modest power densities of 0.1 W/cm/sup 2/, over l0/sup 6//cm/sup 2//s of these small filaments quickly fill the entire reactor volume.