A SIMPLE SOURCE FOR A C-60 PLASMA

We have succeeded in producing a plasma which contained about 70% nega tive C-60 ions. This has been achieved by evaporating C-60 powder dire ctly into the magnetized potassium plasma column of a Q-machine. The C -60 source is a cylindrical stainless steel box with lids that each ha ve a circular hole with an inner diameter equal to that of the plasma column. This source can be heated to about 500 degrees C. The obtained C-60(-) density has been inferred from the decrease in the electron s aturation current to a heated probe or to a heated collector and value s of almost 7 x 10(8) cm(-3) have been obtained.