Detection of trace elements in meteorites using PIXE

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

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

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

Characteristic X-Rays

Characteristic X-Rays

Characteristic X-Rays

Characteristic X-Rays • The energy of the X-Ray is equal to the energy difference between the two orbitals • This energy is characteristic of the element involved

Experimental Setup • Van de Graaff Accelerator - this is the ion beam s

Experimental Setup • Analyzing Magnet - Selects particles based on cha

Experimental Setup • PIXE Chamber - up to five samples can be placed

Experimental Setup • Si-Li Drifted Detector - detects X-Rays and sends

Rob. Win • Used for Spectral Analysis • Mathematically models background radiation (noise) • Finds peaks that are not clearly visible

Rob. Win

PIXE Spectrum

PIXE Spectrum

PIXE Spectrum

Conclusions • The elements found in the meteorites were : Ca Ti Cr Fe Ni Cu Zn Ga As

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.

The End