High-Speed, NaNoscale Secondary Ion Mass Spectrometry

Secondary Ion Mass Spectrometry (SIMS) is an important tool in the study of nanoscale composition of materials; however current instrumentation is slow, requiring long data acquisition times and providing limited resolution. The overall aim of this research proposal is the development of improved SIMS instruments, made possible by new ion source technology. SIMS has been used successfully to study important processes for bioenergy, such as nutrient transport in the rhizosphere, structural characterization of cell walls, and metabolic pathways in complex systems. Researchers use SIMS to collect high-spatial-resolution maps of the elemental or isotopic composition of nanoscale samples. The limited resolution of existing SIMS instruments prevents researchers from obtaining the accurate spatial information required for a deeper understanding of these systems. Phase I was successful in developing a prototype ion source well suited for integration with SIMS instrumentation. Specific objectives included improvements to the ion source: higher output current, improved ion-optics, and increased maximum beam energy.The new ion source is higher-performing, as well as being easier to build and operate. In Phase II this ion source will be used to create a new SIMS instrument. Other major components of the instrument include an ion-focusing column and a dual-polarity mass spectrometer. The primary aims of the research include the integration and testing of these discrete components as well as further improvements to ion source stability and lifetime. This new SIMS instrument will produce elemental maps at few-nanometer resolutions, which are at fundamental physical limits of the technique. Its development will aid academic and commercial researchers developing alternative energy sources, oil and gas exploration, semiconductor technologies, and biomedical innovations. This instrument will also serve researchers exploring the evolution of biological life on Earth and astrophysical phenomena.