Enhanced secondary-ion emission under gold-cluster bombardment with energies from keV to MeV per atom - art. no. 022902

Gold-cluster beams of Au-n(+), n = 1-4, have been used to measure the secon dary-ion emission from organic (biomolecules) and inorganic (CsI) targets o ver the very large energy range of 4 keV to 10 MeV per atom. The nonlinear enhancement of secondary-ion emission yields with regard to the constituent number in the cluster projectiles is shown to vary with the incident veloc ity and the type of secondary ions. For complex secondary ions. the yields as a function of the projectile energy per atom present an unexpected maxim um around 50-80 keV per atom. The yields increase again above 1 MeV per ato m.