Optical emission and surface characterization of stainless steel treated by pulsed microwave-atmospheric helium plasma jetEssam Abdel-Fattah, Ashraf Yehia, Marian Bazavan and Tatsuo IshijimaEur. Phys. J. D, 71 7 (2017) 178DOI: https://doi.org/10.1140/epjd/e2017-80044-7