Spatial characterization of laser induced Yb plasma in argon using optical emission spectroscopy: Pressure effect

Spatial and temporal behavior of laser induced Ytterbium plasma plume is studied using optical emission spectroscopy technique. A third harmonic Nd:YAG nanosecond laser was used to generate Yb plasma plume at different Argon background pressures (1, 10, 102, 103 and 104 Pa). The plasma dynamics was investigated based on the spatial behavior of the excitation temperature coupled with optical time of flight (O-TOF) profiles of neutral Yb emission line (555.65 nm) along the propagation axe of the plasma plume. Drag force model was appropriate to describe the propagation dynamics at all pressures except of the lowest one (1 Pa) where free expansion model is dominant. The velocity distribution of Yb I atoms were extracted using two terms of Shifted Maxwell-Boltzmann (SMB) distribution. The correlation between the spatial comportment of both excitation temperature and O-TOF profiles is discussed.