The maximum target material spray velocity emanating from the rear of a penetrated thin target is studied utilizing the one-dimensional shock-wave theory. A set of experiments is designed to evaluate the analytical results. The targets are 0.0025-cm-thick 1100 aluminum foil and 0.041-cm-thick 1100 Hl4 aluminum plate. The projectiles are made of tungsten and disk shaped. Their diameter is 0.56 em and their thickness is either 0.076 or 0.038 cm. The projectile and target dimensions assure that the one-dimensional assumptions in the theory are valid.. The impact velocity range is from 0.089 to 0.295 cm/µsec. A method is developed to launch unskewed and intact very dense disk-shaped projectiles to high velocity. By using very dense tungsten projectiles the maximum aluminum target material spray velocity is as predicted by the theory well in excess of the projectile impact velocity. A ratio is defined as the maximum target material spray velocity to projectile impact velocity. The experimental ratio points are seen to agree with the predicted values for the impact velocity range covered. Photographic data are presented and analyzed for the fragmentation of material on the leading edge of the target material spray cloud. As the impact velocity is increased the complete fragmentation of material on the leading edge is shown in the photographic data. / Master of Science