Line-Broadening Measurement of C v n=2, Delta n=0 Transitions in a Laser-Produced Plasma

We measured the spectral profiles of the Δn=0, n=2 transitions of C v in laser produced plasmas using both polyethylene and graphite targets. The line profiles were measured using an optical multichannel analyzer (OMA), with 5 ns gate time, yielding line profiles in a single shot with improved accuracy. The line widths measured at about 3 mm from the target surface indicate a high effective ion temperature over 1 keV. This result may be explained by hydrodynamic turbulence in addition to the radial expansion in the laser produced plasma. We also found that linewidths do not vary with time at 3 mm from the target surface, which indicates that the turbulence develops closer to the target surface. An imaging system was constructed to obtain spatially resolved spectra in a single shot. The spatially resolved profiles indicated that the line widths do not vary with position, except perhaps within 2 mm of the target surface.