A scientific tool that can do the same thing is called a spectroscope (early spectroscopes used prisms). You can make your own spectroscope by following the instructions shown below! Assemble the ...

For that, you need something like this gamma-ray spectroscope. Dubbed the Pomelo by [mihai.cuciuc], the detector is a homebrew solid-state scintillation counter made from a thallium-doped cesium ...