ELECTROMAGNETIC LAUNCH OF MM-SIZE PELLETS TO GREAT VELOCITIES

Small body launching that uses gas or plasma faces the fundamental pro blem caused by excess energy loss that is due to the great wall surfac e/volume ratio of the barrel. For example, the efficiency of the plasm a armature (PA) rail-gun acceleration is maximum for 8-10 mm-size bodi es and drops as their size decreases.(1) That is why in the case of nu clear fusion applications, where 1-2 mm-size pellets at 5-10 km/s velo city are desirable, electromagnetic launchers have not yet demonstrate d an advantage over light-gas guns and one is now forced to search for a compromise between the pellet size (increasing it up to #34 mm) and its velocity (decreasing it down to approximate to 3 km/s). As a whol e, the probability of attaining 5-10 km/s velocity for 1-2 mm pellets seems to be rather remote at the present.