Debris cloud expansion around a residual rod behind a perforated plate target

The debris cloud expansion around a residual rod behind a perforated plate target has been studied by means of the laser stroboscope and the flash X-ray observation technique. Especially the bulging at the target rear side, the breaking of the bulge, its fragmentation and the cloud expansion nearby and far from the target are investigated. Rods of tungsten sinter alloy, steel and Ti with aspect ratios 6 to 15 are launched against steel and Al targets at 1250 and 1700 m/s in full and half scales. The cloud expansion scales and depends only weakly on the parameters varied here. The shape of the cloud behaves roughly elliptically. For rod and target material densities pp bigger than pT, the rod fragments show a smaller lateral spread than the target fragments. Target fragments are found within the total cloud volume. Fragments at equal radial distance from the target rear side have roughly the same velocity. The debris also have been caught by a soft catcher for tungsten sinter alloy and steel rods against steel plates in full scale. The evaluation and data reduction deliver information about number, size, shape, material, mass and angle of the fragments. The accumulated number of fragments versus mass can be described by a Mott distribution function. The angular distribution shows a maximum. Increasing impact velocity extends the lateral spread of the particles