Influence of massive projectile size and energy on secondary ion yields from organic surfaces

We investigated the influence of the projectile size and energy using Aun q+ clusters (5 < n < 400, 1 < q < 4) impacting on a glycine target with a 19q–34q keV energy range. We show that both CN fragment and Gly molecular ion yields are equivalent for projectiles with n > 9 and increase with the energy per projectile atoms. A maximum yield of 0.5 (50%) for both CN and Gly was obtained with the Au400 4+ projectile at 136 keV total energy. For Gly , the yield enhancement is linear for Aun when n > 5. Trends for the CN fragment are different. A nonlinear yield enhancement proportional to n3 is observed for Aun when n < 9.