He (23S) helium metastable monitoring through N2+ (B-X) emission in atmospheric pressure plasma jets
Résumé
He (23S) helium metastable is a key state in the energetic transfers occurring in atmospheric pressure plasma jets now widely used for applications related to biology or material processing. Its measurement mainly relies on laser absorption which is not always easy to perform. In this work, we show that a simple way to follow the time evolution of this state can be found in the late time evolution of the transitions emitted from the N2+B state which is mainly populated by Penning ionisation from He (23S).