1. Nitrogen fixation using a
Propeller Arc in air
A novel plasma source (Propeller Arc or PA) utilizes a rotating cathode with a fixed anode to investigation basic plasma mechanisms governing N2-O2 reactions in air plasma.
Peak NOx production efficiency with the PA is ~7×1016 molecules/J at 112 mA. Varying conditions enables investigation of mechanisms.
One goal is to understand why air plasma NOx production efficiency varies with average E/N, this PA scaling with PNOx ~78(E/N)-0.85.
Average E/N = (U/d)/((P/P0)/(T/T0)*N0)
U: average discharge voltage (V)
d: gap distance (m)
P: gas pressure (atm), P0= 1 atm
T: gas temperature (K), T0= 300 K
N0: gas density, 2.43*1025 molecules/m3
Sony Cyber-shot, DSC-RX100 IV, 1000 fps, 1 ms
Time-resolved images (15 Hz)
Efficiency varies with average E/N
DOE Plasma Science Center
Control of Plasma Kinetics
HIGHLIGHT
July 2018 1

2. FLUID DYNAMICS DRIVE SELF-ORGANIZATION OF STREAMERS IN A BUBBLE
Using a 2-dimensional plasma-in-liquid test cell, 2-D capillary waves initiated by streamer discharges have been observed.
Chaotic streamers initially striking at the plasma-liquid interface act as forcing function.
The streamers excite of dominantly capillary wave oscillations propagating along the bubble interface which provides feedback to the streamers.
The oscillations lead to self- organization of the locations at which streamers strike the interface, which in turn further enhances the dominant oscillation mode.
Back-lit interfacial capillary oscillations
DOE Plasma Science Center
Control of Plasma Kinetics
HIGHLIGHT
July 2018 2