Ion-energy distributions in liquid-metal-ion sources

Energy distributions of mass-separated ions emitted from liquid-metal-ion sources using Ni-B-Si and Pt-P-Sb alloys have been measured in a dynamic range of four orders of magnitude. Low-energy tails are observed on the energy-per-unit ion charge for singly-charged ions, in contrast with doubly-charged ions. The higher ion-emission current brings about longer tails. Rather flat tails are also observed on the high-energy side for M⁺ ion species in the Pt-P-Sb alloy LMIS, where the M²⁺ intensity is larger than the M⁺ one. The origins of these energy tails are discussed.