Production of Liquid Cluster Ions by Nozzle Beam Source with and without He Gas

We developed a new type of cluster ion source which could produce various kinds of liquid clusters such as water, methanol, ethanol and octane clusters. When the vapor pressure was larger than one atm, the water and ethanol clusters could be produced by an adiabatic expansion phenomenon without adding He gas. The peak size of the cluster ions increased with the increase of the vapor pressures. When the source temperature was at room temperature, the water and ethanol clusters were also produced by adding He gas. In another case of producing liquid clusters such as methanol and octane clusters, He gas was added to mix up with vapors of liquid materials. When the He gas pressure was larger than a few atms, the methanol and octane clusters were produced at a vapor pressure of two atm. The peak size increased with increase of the vapor pressure as well as the He gas pressure.