High Performance Compact SIMS for Geoscience Laboratories
CAMECA’s IMS 7f-GEO is a new mono-collection compact SIMS model specifically designed to perform high precision / high throughput measurements in geological samples, i.e. stable isotopes, REE (Rare Earth Elements), trace elements... The analysis spot size can be adjusted to a few tens of microns. Images of trace elements and isotopes can be recorded on Field of View ranging from a few microns up to 500µm.
A unique detection system for high isotope ratio reproducibility
Derived from our proven IMS 7f and IMS 1280 instruments, the IMS 7f-GEO is equipped with a new, unique detection system combining a double Faraday cup detector system and an Electron Multiplier. Thanks to this configuration, acquisition time is shortened, and analyses are run in a pseudo bi-collection mode ensuring sub-permil precision in stable isotope ratio measurements. The double Faraday cup system is combined with a fast mass peak switching system (as fast as 0.3 sec at high mass resolving power) for further benefits in terms of precision and analysis throughput.
Stable isotope analysis:
Delta18O measured on a synthetic quartz sample.
Each data point corresponds to a different spot of the sample.
The runs are distributed over an area of 15mm in diameter across the sample.
Total integration time: 56s
Spot to spot reproducibility (1s):
Mean internal error (1s): 0.27 permil
... And greatly improved analysis throughput
The IMS 7f-GEO achieves a major improvement in analysis throughput thanks to the implementation of the double Faraday cup detector system working in charge mode as demonstrated in the 18O/16O isotope ratio analysis above:
- required precision: 0.4‰
- 18O signal intensity: ~2e6c/s
- in EM/EM standard mode, requested measurement time is 3016 sec. while in the new IMS 7f-GEO FC/FC charge mode, it falls down to 56 sec.