Contact

Dr. Axel Renno
Department of Analytics
Phone: +49 351 260 - 3274

Super-SIMS

Super-SIMS (SIMS = Secondary ion mass spectrometry) is an ultrasensitive analytical method for the determination of stable elements at the ultratrace level. The HZDR Ion Beam Center developed the set-up by coupling a conventional SIMS to a 6 MV tandem accelerator.

The Department Accelerator Mass Spectrometry and Isotope Research at the Institute of Ion Beam Physics and Materials Research currently operates the instrument. Measurement tasks and the further development of the equipment are defined in close coordination with the Helmholtz Institute Freiberg for Resource Technology. The device is operated in beam times. The application is done via HZDR-GATE portal.


Technical Specifications

  • SIMS-source (Cameca IMS 7fauto) connected to a 6 MV tandem accelerator
  • 2 to 3 orders of magnitude lower detection limits (up to 10 ppt or 0,00001 μg/g, highly depending on analyte and matrix as conventional SIMS)

Future Applications

  • Ultratrace elements in minerals for the geochemical exploration of deep-seated ore deposits
  • Provenance analysis and forensics

Sample Requirements

  • Extremely well polished and flat samples with a maximum diameter of 1 inch (25.4 mm)

Limitations

  • Only solid and vacuum-stable samples
  • Destructive
  • Standard/reference materials needed
 
Super-SIMS Housing ((c) Oliver Killig) ©Copyright: Dr. Merchel, Silke, HZDR/Oliver Killig

Super-SIMS Housing (c) Oliver Killig


How does it work? ►

A sputter source is used to focus a Cs+-beam onto a very flat and well polished sample surface. The extracted negative ions (elements or molecules) are electrostatically and magnetically separated. A first isobar suppression is gained right in the ion source, unless they form any negative ions (e.g. no formation of Mg- when analyzing Al).

Ions with the correct energy, mass and charge are injected into the 6 MV accelerator and accelerated to the positively charged high-voltage terminal. Negative ions are passing an area filled with argon gas, thus, losing electrons from the outer shell. Thereby, all existing molecules are destroyed. The henceforth multiple-positively charged ions are accelerated a second time in the direction of the other end of the accelerator.

At the so-called high-energy site all ions are again magnetically and electrostatically separated before they are finally detected by Faraday-Cups (major elements) or gas ionization detectors (trace elements).

Secondary ion mass spectrometer from above ©Copyright: Schulz, Tina

Secondary ion mass spectrometer from above

Foto: Tina Schulz

 
The 6 MV Accelerator at the Ion Beam Center of the HZDR ©Copyright: HZDR

The 6 MV Accelerator at the Ion Beam Center of the HZDR

Foto: HZDR


Basic Literature ►

  • S. Matteson, Issues and opportunities in accelerator mass spectrometry for stable isotopes, Mass Spectrometry Reviews 27 (2008) 470-484
  • E. J. von Wartburg, Messung von Isotopenverhältnissen stabiler Spurenelemente mit Beschleuniger-Sekundärionen-Massenspektrometrie, Dissertation, ETH Zürich (2007).
  • E.E. Groopman et al. Rapid, molecule-free, in situ rare earth element abundances by SIMS-SSAMS, Journal of Analytical Atomic Spectrometry, 32 (2017) 2153 - 2163

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