Influence of the nozzle head geometry on the energy flux of an atmospheric pressure plasma jetThorben Kewitz, Christoph Regula, Maik Fröhlich, Jörg Ihde and Holger KerstenEPJ Techn Instrum, 8 1 (2021) 1DOI: https://doi.org/10.1140/epjti/s40485-020-00061-4