Hope College Physics Department
Research Experiences for Undergraduates
|Project Title:||Differential PIXE Analysis of Layered Automobile Paint|
|Student Name:||Kiley Spirito|
|Student's Home Institution:||Hope College|
|Research Advisor:||Dr. Paul DeYoung and Dr. Graham Peaslee|
|Source of Support:||
This material is based upon work supported by the National Science Foundation under grant No. PHY-0969058.
Analysis of multi-layered samples is both time consuming and destructive;
the layers must be mechanically separated and chemically dissolved, destroying
the sample in the process. Particle Induced X-ray Emission (PIXE) uses a particle
accelerator for non-destructive chemical composition analysis. Differential
PIXE uses varying beam energies to penetrate different depths into the sample.
In multi-layered samples, the different energies produce x-rays from only the
layers which the beam passes through. A target element unique to each layer
is used to tell the layer in which the beam stops at varying energies. Concentrations
are obtained from the spectra using the peak fitting program GeoPIXE, which
is particularly useful because it has multi-layered fitting capabilities. By
adjusting the thickness of a layer until the target element concentrations
are consistent across all energies, it is possible to approximate the thickness
of that layer without taking it apart. With this method, at least two layer
thicknesses in the five layer sample can be determined.
_____________________________________________________________________________________________________________________________________________________________________________________________________ Publications and Presentations:
“PIXE Analysis of Automobile Paint Layers” Kiley Spirito. 2011 Celebration of Undergraduate Research, Hope College, April 15, 2011.