Influence of multi-pin anode arrangement on electric field distribution characteristics and its application on microgreen seed treatment

This research proposes the design of a multi-corona discharge model to study the suitable electric field characteristics on sustaining a large stable plasma for microgreen seed treatment. The influence of an increase in the number of pin anode (N${}_P$) and the gap distances between two adjacent pins anode (G${}_P$) on electric field characteristics are studied by the finite-element method. The results have indicated that the electric field characteristics from a large N${}_P$ with the 5 mm G${}_P$ are suitable to sustain the large stable air plasma because of the high virtual semi-uniform electric field and the wider area of intense electric field stress. Then, the microgreen seeds are treated by the designed air multi-corona discharge model on a copper cathode (CC) or water cathode (WC). The germination rates of plasma-treated seeds on the CC and WC are higher than the ones of the control group of about 8% and 6% at 24 h cultivation time, respectively. The growth rates of plasma-treated seeds on CC and WC are greater than the ones of the control group of about 3.5 and 2.5 times, respectively. It can be confirmed that both plasma-treated cases have shown a positive effect on germination and growth enhancement. (© 2020 Wiley‐VCH GmbH)