Interpret+the+data+collected+from+PIXE+and+XRF

Back to milestone map Interpret the data collected from PIXE and XRF

Explain what a spectrum is

For both the PIXE and XRF labs x-rays of specific energies are detected. The detections are then sent to a computer. The list of detections can then be formated into a spectrum chart for analysis. The spectrum has the energy of the x-rays as the x-axis and the number of detections as the y-axis. These spectrums can be seen below.

Explain how energy is given off and turned into a spectrum

When the x-ray or proton beam smashes into the sample, it knocks an electron out of an inner electron shell. This causes an electron from a higher electron shell to jump down to fill the hole. This jump releases energy in the form of an x-ray. This energy is what is detected and sent to a computer to be put into a spectrum.

Explain how to analyze spectrum

Both PIXE and XRF are similar in the way the data is analyzed, but the XRF data has an extra step that needs to be taken before it can really be analyzed. In order to analyze the XRF data the proper energies need to be aligned with the proper channels.



By using the two above spectrums I am able to convert the channels to energies. I know what the energies of both copper and titanium are, 8.04 and 4.51 respectively. I could then make an equation to convert to energies. The spectrums below have already been converted to have energy as the x-axis. Now that you have the spectrum you can analyze your data. To analyze you look at the peaks on the spectrum. Depending on what energy the peak is associated with, the peak will tell what element is present.

XRF data:



PIXE data:



Explain results of both PIXE and XRF

PIXE:

In the PIXE data I was able to interpret the data to see that in the run on the screw there was Chromium, Iron, and Nickel. In the fish run I was able to see Argon, Chromium, Iron, and Calcium.

XRF:

In the XRF data you can see that there was much more noise in the data so trace amounts of elements would be harder to see. In the first fish I saw Chlorine, Calcium, Arsenic, and Technetium. In the second fish there was Chlorine, Calcium, and Technetium.

Future Goals:

In the future for this project I plan to be able to more accurately compare the XRF and PIXE. I also hope to learn how to analyze concentrations of elements from the data. I also hope to get more data from more fish and possibly even mollusks or bottom feeders.

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