Helium 3 first ionisation energy?

Question

Does the Helium 3 isotope have different first ionisation energy than "normal" helium or is it the same?

score 2 · Accepted Answer · answered Jan 25 '17 at 12:07

2

This proved surprisingly difficult to Google, but I found this paper:

Energy levels for the stable isotopes of atomic helium (4He I and 3He I), Donald C Morton, Qixue Wu, G WF Drake, Canadian Journal of Physics, 2006, 84(2): 83-105

that calculates the ionisation energies for ${}^3$He and ${}^4$He.

You would expect the binding energy of the electron to decrease with reduced mass, and that is what the paper reports. The ionisation energy of ${}^3$He is about 0.2% smaller than the ionisation energy of ${}^4$He.

answered Jan 25 '17 at 12:07

John Rennie

355,118

thank you very much! I would upvote you but I cant becose I dont have enough points – wav scientist Jan 25 '17 at 12:39
Converting those values from MHz gives He-4: 24.5873893 eV and He-3: 24.5860927 eV, with uncertainty ~1 in the last digit. – PM 2Ring Sep 07 '23 at 00:45

Helium 3 first ionisation energy?

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