Mass Distribution of Products of Cluster Impacts

Mass d i s t r i b u t i o n s of i o n i c atomic and molecular fragments s p u t t e r e d from carbon s u r f a c e s by s i n g l y charged p o s i t i v e c l u s t e r ions con ta in ing 80 water molecules have been determined. With c l u s t e r k i n e t i c energy of 240 keV s i g n i f i c a n t y i e l d s of molecular fragments con ta in ing up t o 2 1 carbon'atoms were observed. Ion y i e l d s were used t o es t ima te r e l a t i v e y i e l d s of n e u t r a l fragments with t h e assumption t h a t r e l a t i v e y i e l d s of t h e r e s p e c t i v e i o n i c and n e u t r a l s p u t t e r i n g processes were determined by k i n e t i c f a c t o r s which could be evaluated independently. The der ived n e u t r a l y i e l d s were t h e n used t o e s t i m a t e t h e f r a c t i o n of t o t a l p r o j e c t i l e energy u t i l i z e d i n evapora t ive cool ing, i . e . s p u t t e r i n g . The r e s u l t s i n d i c a t e a l a r g e f r a c t i o n of t h e energy a v a i l a b l e is used i n t h e c l u s t e r s p u t t e r i n g process.