Refraction filter

I was playing around with a refraction filter all day. It has a bandwidth of only ten nanometers - I think I should speak of band-narrow here, but thats me - and you can adjust it from 400 to 720 nanometers.

Together with a spectrometer you can, say, look at an Argon line and see where in the plasma Argon atoms get excited. Or you can't, because the really strong neutral argon lines are at

well, fuck.

I just realized that the spectra-analyser software was lying to me. It told me that my line at 763 nanometers was an Iron/Chromium line, but there is also an Argon I line right smack at 763.51 nanometers, and the damn traitor PLASUS never let on! Thank god for the ASD (Atomic Spectra Database). Excuse me while I go and redo all my analysis.