Automated ion imaging with the NanoSIMS ion microprobe

Automated ion imaging systems developed for Cameca IMS3f and IMS6f ion microprobes are very useful for the analysis of large numbers of presolar dust grains, in particular with respect to the identification of rare types of presolar grains. The application of these systems is restricted to the study of micrometer-sized grains, thereby by-passing the major fraction of presolar grains which are sub-micrometer in size. The new generation Cameca NanoSIMS 50 ion microprobe combines high spatial resolution, high sensitivity, and simultaneous detection of up to 6 isotopes which makes the NanoSIMS an unprecedented tool for the analysis of presolar materials. Here, we report on the development of a fully automated ion imaging system for the NanoSIMS at MPI for Chemistry in order to extend its analytical capabilities further. The ion imaging consists of five steps: (i) Removal of surface contamination on the area of interest. (ii) Secondary ion image acquisition of up to 5 isotopes in multi-detection. (iii) Automated particle recognition in a pre-selected image. (iv) Automated measurement of all recognised particles with appropriate raster sizes and measurement times. (v) Stage movement to new area and repetition of steps (ii)–(iv).