Characterization of schlieren light source using laser-induced optical breakdown in argon

An argon-purged open chamber has been used to create a high-intensity laser-induced spark light source for use in a schlieren system. This light source is approximately 450% higher intensity than a similar discharge in air, providing improved contrast in schlieren images for flowfields that generate strong emissions. The spark formed in argon shows slightly less intensity variation from shot to shot. This light source can be easily synchronized with triggering events in the flowfield, and the short duration of the laser-induced optical breakdown discharge makes it well suited for imaging moving shocks and turbulent flows.