I've been looking everywhere for information on the absorption spectra of molecular hydrogen. I need some pretty exact numbers. If anybody can point me in the right direction it would be greatly appreciated.
Ok ..that's quite a bit more basic than what I thought you were looking for. That table gives very accurate values for the relative energies and molecular constants for all of the measured electronic states of hydrogen. Based on your first post, that's what I thought you wanted.Thanks SpectraCat!
Just a quick one, brace yourself, this question mught be a bit retarded...
How do those tables work?
I was hoping to find something like a list of constants associated with a list of frequencies.
Here's the formula i was hoping to plug the values into:
If= Io exp(-k(f)nx)
n=atoms per unit vol
k(f) = the stuff i've been searching everywhere for
What is the frequency of your laser?Thanks again SpectraCat
I'm not really sure how to answer that question, maybe if i just tell you what i'm planning on doing with the information you can help me figure it out?
Pretty much what i want to do is have a laser that works at a frequency that is well absorbed by hydrogen pointed, via a whole lot of almost pure hydrogen gas (from a pipeline), at a photodetector. So, looking at that formula, I can get readings for Io and If, I'll also know the distance and k(f). I want to have a way of getting n.
It's an exercise in electronics more than anything else (i need to make sure that there is no way in heck the associated circuit would spark or heat up too much).
I dont really know much about transitions...
I thought you said you wanted it at a frequency at which hydrogen absorbs? That means UV .. in fact, the whole discussion we have been having is pretty much moot in terms of the experiment you describe. According to that table I linked, the lowest lying transition of H2 is in the vacuum UV at around 112 nm .. that means that even if you could get a laser operating at that frequency (expensive and tricky), you wouldn't be able to pass the beam through the air, since the air molecules themselves absorb at those frequencies.I haven't decided yet, something infra-red would be best i think. I can get a tunable laser if need be
That has nothing to do with your question .. it is a calculation for the H-atom first of all, and second of all, it is only valid for emission (or absorption at extremely high temperatures).And i just read that the smallest IR wavelength that can be absorbed by hydrogen is 823.5nm. I'm not really sure of the maths because i've never done the calculation myself, if you want to check it out it's here: