Abstract
We performed impact experiments to measure the relation between the cumulative mass of ejecta and ejection velocity (cumulative mass-velocity relation) for various impact angles (15 to 90 deg from the horizontal target surface). Polycarbonate projectiles were accelerated to about 170 to 200 m/s using a single-stage light-gas gun. Targets were small soda-lime glass spheres. Collector boxes were set around the glass sphere targets. After experiments, we measured the masses of the glass spheres collected by the collector boxes, and determined the spatial distribution of ejecta deposit around a crater. We then estimated the ejection velocities from the distances between the collector boxes and a crater. Based on these results, we determined the cumulative mass-velocity relation for ejecta with velocities of a few m/s in oblique impacts. The present data showed that the cumulative mass decreases with increasing impact angle. On the other hand, it was demonstrated that the present data were scaled well by pi-group scaling, irrespective of impact angles.
