Abstract: | The refractive fringe diagnostic was applied to a spherical shock wave in air generated by an arc discharge. A pulsed ruby laser, synchronized with the shock generation, was used as the probe beam. Both fine and coarse fringes were observed and were modelled computationally. Agreement with the broad features of the density profile predicted by theory was obtained, but the gradient of the theoretical shock rear was found to be too shallow. The shock tail was seento be stationary over a duration of hundreds of microseconds. |