Mass Analyses of Cluster Ion Beams by Wien Filter

Abstract

Distributions of mass of cluster ion beams were investigated by using a Wien filter with permanent magnets, which is 200 mm in length. Resolving powers of the Wien filter in the mass range of 10 3 to 10 6 a.m.u. were estimated. The Wien filter is useful for studies of clusters having 10 2 –10 4 molecules/cluster. Argon cluster beams were ionized up to about ten charges when ionizing current was 15 mA. There were two different mass groups in hydrogen cluster beams produced, even at gas temperature of 77.3 K.