H
" Isotope ShiftThe H" Isotope Shift is the only lab that all students are required to participate in. The experiment consists of taking a tube of hydrogen and deuterium (hydrogen with an extra neutron) and exiting it thermally until it begins to shed energy by emitting light. The physical reason that this happens is when an atom has extra energy imparted to it one or more or it's electrons will take that energy and enter into a higher-level energy state. After a short period of time, usually much less than a second, the electron will drop to a lower energy state and emit a particle of light to shed it's energy. Nature will always seek the lowest energy-state it can enter.
Since there are only so many energy states the electron can occupy and change between, and since there is a direct relationship between the energy given to the photon and the wavelength of the photon emitted, we can only have certain wavelengths emitted. These wavelengths correspond to very thin lines of certain colors that cannot be seen with the naked eye, but can be observed with specialized magnifying instruments called spectrometers.
In the H" Isotope Shift lab we acquaint ourselves with spectrometry, the study of these spectral lines emitted by atoms, by examining the various lines emitted by the helium-deuterium mix of exited atoms. Once the entire spectrum has been mapped we readjust the spectrometer to magnify even more and attempt to observe the slitting of the red doublet. This splitting occurs because deuterium is slightly heavier than hydrogen and thus the spectral line is emitted at a slightly different wavelength.
For some, this measurement is trivial. For others it is the equivalent of pushing a boulder to the top of a hill, watching it slowly tumble back into it's preferred lower energy-state, and then doing it again, and again, and again. Pushing until you can't see, your back aches, your mouth is dry, until finally, in a moment of triumph, you have worn the hill away and you can see in a single moment of clarity that…that...there still isn't any stupid red doublet.