[1] Masaryk Univ, Fac Sci, Dept Plasma Phys & Technol, Kotlarska 267-2, Brno 61137, Czech Republic
[2] PlasmaSolve, Sukova 49-4, Brno 60200, Czech Republic
[3] AGC Plasma Technol Solut, Rue Louis Bleriot 12, B-6041 Charleroi, Belgium
[4] Univ Namur, 61 Rue Bruxelles, B-5000 Namur, Belgium