Instruments - SHRIMP SI

SHRIMP SI (stable isotope) is an instrument dedicated to low mass range stable isotope analysis. While SHRIMP II was designed to permit stable isotope analysis, there were a number of compromises in the design to allow the flexibility of U-Pb analysis and stable isotope analysis.

SHRIMP SI is designed to facilitate stable isotope measurements alone. It includes some elements of both SHRIMP I and SHRIMP II. The features from SHRIMP I include the sample-stage motors being mounted externally to the vacuum chamber, and the intermediate extraction lens to produce a crossover in the secondary extraction. The mass analyzer is the same design as SHRIMP II.

The multiple-collector for SHRIMP SI is designed for low mass. This means that unit mass spacing is further apart and allows the use of standard ETP multipliers in the multiple collector, with fully shielded containers for each multiplier. In measuring stable isotopes, there is little variation in the collector set up and so the design has been simplified with fewer control systems in the chamber.

SHRIMP SI includes a fully redesigned primary column. The beam transport is based around Kohler illumination for spot analysis, but also has a crtical illumination capability for submicron illumination. The source chamber is designed for compartmentalized space and differential pumping between sub-chambers.

SHRIMP SI is funded through an ARC LIEF grant and includes partner organizations University of Melbourne, University of Queensland, University of Tasmania (CODES), University of Wollongong, Curtin University and University of Western Australia (through the John deLaeter Center for Mass Spectrometry), Geoscience Australia, CSIRO, and Australian Scientific Instruments.