Resources
This page has a few Excel spreadsheet tools that I have used for various aspects of my research. They are simple, for the most part, but they've been pretty helpful, so I thought I would share them.
Bragg Analyzer Crystal Selector
While performing spectroscopy measurements at Sector 16 IDD (HPCAT) of the Advanced Photon Source, collaborators and I needed to get different analyzer crystals in order to resolve different atomic spectral lines with the spectrometer.
The spectrometer is a pretty simple device. X-rays radiate off of your sample, and hit an analyzer crystal that sits at an angle (theta) from the sample. A detector sits on an arm at an angle of two-theta. Only x-rays that meet the Bragg condition for the crystal will diffract into the detector. Basically, you're doing a diffraction measurement with a relatively narrow window of angles; the angle dependence is then converted into energy space.
I constructed a pretty simple spreadsheet to help us decide what Bragg Crystal Analyzer we should use for a given experiment. The spreadsheet allows you to select an energy (the one you want to measure spectra around), and then it chooses the highest angle reflection off of a Si or Ge crystal to define the "cut" of the crystal that you need (e.g., (111), (110), etc.).
XES Spurion Calculator
In performing x-ray emission spectroscopy measurements at Sector 16 IDD (HPCAT) of the Advanced Photon Source, we sometimes noticed that our spectra would have extra peaks. It took us a little while to figure out what these were, but they turned out to be "contamination" peaks from other elements that "leak" into the spectra. Because the spectrometer is really a diffraction-measuring instrument, any energies that meet the Bragg condition can make it from the sample to the detector. And, because we generally use Si or Ge, the high-symmetry cuts that we use have harmonics (e.g., (220), (440), etc.). So, while you have an angular range around, let's say, the (220) reflection of a Si analyzer crystal, if you have something in your sample that will meet the diffraction conditions for (440), then you'll get that intensity too.
Because we do diamond anvil cell experiment, the gasket itself can contribute to the signal. In some cases, we found that the Be gaskets that we used had small amounts of Cu, and the Cu K-alpha1 and K-alpha2 peaks would "leak" into spectra that we may be acquiring on a completely different sample, like Ce. Below is an example of a spectra with prominent extra peaks in a high-pressure experiment. I adopted language from neutron scattering, and I called these spurions, though the origin of the spurions in our x-ray experiments are far more limited than those that you can get in neutron scattering experiments (i.e., you can shield x-rays pretty effectively).
I put together this spreadsheet to calculate what elemental x-ray fluorescence peaks would meet the Bragg conditions of the crystal that we were using.
The spreadsheet can be downloaded here.