The effect of microwave power on the Ar9+ and Ar13+ optical emission intensities and ion beam currents in ECRIS - Kronholm, Risto; Sakildien, M.; Neben, D.; Koivisto, Hannu; Kalvas, Taneli; Tarvainen, Olli; Laulainen, J.; Jones, P. (AIP Publishing, 2018)