Optical emission investigation of laser-produced MgB2 plume expanding in   an Ar buffer gas
  Optical emission spectroscopy is used to study the dynamics of the plasma generated by pulsed-laser irradiation of a MgB2 target, both in vacuum and at different Ar buffer gas pressures. The analysis of the time-resolved emission of selected species shows that the Ar background gas strongly influences the plasma dynamics. Above a fixed pressure, plasma propagation into Ar leads to the formation of blast waves causing both a considerable increase of the fraction of excited Mg atoms and a simultaneous reduction of their kinetic flux energy. These results can be particularly useful for optimizing MgB2 thin film deposition processes. 
S. Amoruso, R. Bruzzese, N. Spinelli, R. Velotta, X. Wang, C.   Ferdeghini