2. Detection of trace elements in meteorites using PIXE Presented by: Sasha dos-Santos

3. Goals To determine the chemical composition of several meteorites To estimate the concentration of chemicals in PPM (parts per million)

4. Particle Induced X-Ray Emission Spectrometry A method of determining the chemical composition of a substance Has been in use since the 1970s Used in fields such as astrophysics, medicine, and environmental science

5. Characteristic X-Rays

8. The energy of the X-Ray is equal to the energy difference between the two orbitals This energy is characteristic of the element involved

9. Experimental Setup Van de Graaff Accelerator - this is the ion beam source

10. Experimental Setup Analyzing Magnet - Selects particles based on charge and mass

11. Experimental Setup PIXE Chamber - up to five samples can be placed in the chamber at a time

12. Experimental Setup Si-Li Drifted Detector - detects X-Rays and sends input to a multichannel analyzer

13. RobWin Used for Spectral Analysis Mathematically models background radiation (noise) Finds peaks that are not clearly visible

14. RobWin

15. PIXE Spectrum

18. Conclusions The elements found in the meteorites were : CaTiCr FeNiCu Zn GaAs

19. Conclusions Next step is to use a process called spin coating to produce thin film samples Then use thin film standards to determine chemical concentrations in the order of micrograms / sq. cm.

20. The End