Resonant optical schlieren system for plasma flow studies

A dye laser, pumped by ruby second harmonic radiation at 3471 Å, emitting ∼5-mJ, 20-nsec pulses with a bandwidth of 0.3 Å, has been developed as a light source in a schlieren optical system which utilizes enhanced refractivity to examine plasma flow phenomena. When the dye laser is tuned adjacent to the BaII ion resonance line at 4554 Å, the sensitivity of the system to density gradients in a barium plasma becomes 100–1000 times greater than can be achieved with nonresonant light sources which rely on the free electron contributions to plasma refractivity. Absorption effects also yield data on plasma flow patterns.