Secondary ion emission from silicon and arginine targets bombarded with large Ar cluster ions

Secondary ions emitted from Si and arginine targets have been investigated under large Ar cluster ion bombardment. Incident ion beams with energies from 7.5 to 30 keV were used and the mean size of the Ar cluster ion beams was about 1000 atoms per cluster. The effects of incident cluster-ion size on secondary ion spectra were investigated under bombardment by size-selected Ar cluster ions. The yields of secondary cluster ions such as Si6+ ions increased rapidly with incident size relative to Si+. On the other hand, molecular ions of arginine and characteristic fragment ions were measured with high sensitivity. When large Ar cluster ions such as Ar1500 were incident on the arginine target, molecular ions of arginine were measured with small amounts of fragment ions. (author)