Vortex gas lens.

A vortex gas lens concept is presented. Such a lens has a potential power density capability of 10(9)-10(10) w/cm(2). An experimental prototype was constructed and the divergence half angle of the exiting beam was measured as a function of the lens operating parameters. Reasonably good agreement is found between the experimental results and theoretical calculations. The expanded beam was observed to be steady, and no strong, potentially beam-degrading jets were found to issue from the ends of the lens. Estimates of random beam deflection angles to be expected due to boundary layer noise are presented; these angles are very small.