[urtula]

hallo all,
I was wondering the following thing: when using a He-Ne laser, you pump some energy in the system to get the He excited, but why only the He atoms?

If you pump energy in the systems, wouldnt the Ne atoms get excited too ? (and I am not speaking about them getting excites because the collisions with the He atoms).


Is this simply because it takes less energy to get the He atoms excited then the Ne atoms (though , the difference is very very small).
Or is there more to it.