Seminarium: MeV TOF-SIMS application in biology and forensics & Diamond detectors, investigations by MeV ion microbeams

  • Datum:
  • Plats: Ångströmlaboratoriet Å2004
  • Föreläsare: Zdravko Siketic & Milko Jaksic, Ruder Boskovic Institute, Kroatien
  • Kontaktperson: Daniel Primetzhofer
  • Seminarium

MeV TOF-SIMS application in biology and forensics:
Time-of-flight Secondary Ion Mass Spectrometry using MeV heavy ions (MeV TOF-SIMS) is a newly developed mass spectrometry technique used for molecular identification and imaging of organic samples. In MeV TOF-SIMS, MeV ions interact with the surface layers of the sample mostly through the electronic stopping, causing desorption of intact molecular ions and making the determination of sample molecular composition much easier. Several orders of magnitude larger yields, as well as less fragmentation, are expected for larger molecular masses when MeV ions are used for the excitation, which is especially important for imaging of organic samples with a micrometer lateral resolution.

Recent results on the application of MeV TOF-SIMS in the analysis of biological and forensic samples will be presented. MeV TOF-SIMS was successfully applied for the 2D imaging of the various lipids in the liver tissue and investigation of chemical changes in the body fluids (serum and urine) of the healthy and diabetic mice. Secondly, MeV TOF-SIMS in combination with Particle Induced X-ray Emission (PIXE) was applied to determine deposition order of the different writing tools for forensic document examination.

Diamond detectors, investigations by MeV ion microbeams

Specific advantage of the ion microprobe facility is its capability to deliver variety of ion species and their respective energies to the specific position of impact on the target with sub-micrometer precision. We have utilised this capability to characterise the single crystal diamond material, for its application as a radiation detector. Studies of diamond spectroscopic features, efficiency, radiation hardness, high temperature operation, long term stability etc. will be presented to illustrate advantages that ion microprobe systems could provide in variety of applications. Presentation will conclude with an outlook to other single ion techniques where ions could be used either as a probe of specific material/device characteristics, or as a tool to change their properties.