ANU sells time machine

After a comprehensive evaluation process, researchers in Poland and Japan have announced they will become the newest owners of the Sensitive High Resolution Ion Microprobe (SHRIMP IIe), a machine manufactured by Australian Scientific Instruments (ASI), a division of ANU Enterprise and part of the broader ANU Innovation portfolio.

ASI General Manager, Dr Ed Roberts, said, “The acquisition of the SHRIMP IIe will allow these researchers to look back billions of years in time to address longstanding questions about the geological history of the Earth.

“The instrument will be used for research into subjects as diverse as climate change, mineral and oil deposits, and the origins of the solar system. This is the second SHRIMP IIe in Western Europe and the third in Japan, and will give researchers enhanced access to the most advanced ion microprobe.”

Ironically, since the instrument weighs around 12 tonnes, SHRIMP stands for Sensitive High Resolution Ion Microprobe. The SHRIMP IIe advanced geochronology instrument was developed at the Research School of Earth Sciences at ANU. It is designed for in-situ measurement of elemental and isotopic compositions of micron-scale areas on the surface of solid samples, based on the principles of secondary ion mass spectrometry (SIMS).

The analysis of geological samples is complicated by the presence of complex isobaric interferences that require high mass resolving power to separate the isotopic species of interest. The high mass resolution of SHRIMP IIe is achieved by the use of a large double-focusing mass spectrometer with energy and mass refocusing.

The unique design allows operation with wide slits, allowing high-sensitivity measurements of isotopic compositions of trace elements at high mass resolution. This facilitates accurate analysis of the isotopic composition of trace elements at concentrations of even a few parts per million. For most elements, routine detection limits of a few parts per billion are readily achieved.

This high sensitivity permits analysis of very small amounts of sample; a typical spot is 25 µm in diameter and less than 3 µm deep. The high-quality reflected light imaging system in SHRIMP IIe allows micron-scale placement of probe spots into specific target areas.