Phase resolved optical emission spectroscopy of coaxial microplasma jet operated with He and Ar J. Benedikt, S. Hofmann, N. Knake, H. Böttner, R. Reuter, A. von Keudell and V. Schulz-von der Gathen Eur. Phys. J. D, 60 3 (2010) 539-546 Published online: 28 September 2010 DOI: 10.1140/epjd/e2010-00246-9