SHRIMP Sensitive High Resolution Ion Microprobe
SHRIMP is a mass spectrometer specialised for in situ analysis of geological materials. A focused primary beam of oxygen or cesium ions is used to sputter 10-30 µm areas of samples. A fraction of the material sputtered from the sample becomes ionised and these secondary ions are transferred to the mass analyser. Ions are separated according to their mass to charge ratio but both molecular and atomic ions can occur at the same mass. SHRIMP is big to allow separation of these different ions. SHRIMP is used for U-Pb geochronology, stable isotope analysis, trace element analysis, and looking for nucleosynthetic anomalies from the early solar system.