The NanoSIMS 50L (nanoscale secondary ion mass spectrometry) is an ion microprobe that was developed for in-situ isotopic and trace element analysis of ultra-fine features. With its unique coaxial lens design, it extends traditional SIMS analysis to extremely small spatial scales, achieving lateral resolutions down to 50 nm and small sputtering depths. The NanoSIMS attains extremely high sensitivity at high mass resolution, with detection limits extending to ppb levels, and can measure up to seven masses in parallel. The instrument is equipped with cesium and oxygen primary ion beam sources for analysis of positive and negative secondary ions.

The unique features of the NanoSIMS 50L allow for detailed elemental and isotopic analysis of sub-micron grains and inclusions from precious astromaterials, and the investigation of fine-scale heterogeneities within a sample. NanoSIMS analyses can be conducted as spot measurements, depth profiles, line scans, or raster ion images. In ion imaging, the primary ion beam is rastered over a sample region and chemical and isotopic maps are produced. A multitude of sample types can be analyzed, including polished petrographic sections, fine-grain dispersions, samples pressed into Au or In, electron transparent thin sections (produced through ultramicrotomy or focused-ion-beam preparation) used for TEM analysis.

Scientists at ARES use the NanoSIMS 50L to analyze isotopes in the following components in meteorites: matrix material, presolar grains, organic matter, refractory inclusions (CAIs), chondrules, carbonates, apatite, anhydrous and hydrated minerals. Additionally, the fine-grained nature of interplanetary dust particles and comet Wild 2 samples returned by NASA’s Stardust mission make the NanoSIMS the perfect analytical tool for their study. The ability to analyze at smaller spatial scales has enabled unique insights spanning stellar evolution and nucleosynthesis, interstellar and early solar system processes, and planetary formation that cannot otherwise be attained.

Electron Beam Laboratory Suite

The Cameca NanoSIMS 50L in Action: Research scientist Ann Nguyen selects a precious astromaterial sample to analyze for its isotopic composition at fine spatial scales down to 50 nm.