Zeeman Spectroscopy

STEP 1: Adding and manipulating energy levels

Add the 6p and 7s energy levels on the energy graph on the by clicking the "Add Energy Level 6p" button and then "Add Energy Level 7s" button. A transistion between the two levels will automatically appear. You can change individual energy values by clicking and dragging the level with the mouse from the left side of the energy graph.

STEP 2: Viewing the spectrum

The experimental equipment for the Zeeman Effect consists of a electro-magnet (with a variable field), a mercury gas lamp, a lens, a green filter and a Fabry-Perot etalon. A graphic of this equipment appears on the left side of the screen. You will notice that the mercury gas tube that is positioned between two electromagetic coils starts to glow immediately after the transition between the 7s and 6p energy levels appears. The real (top) spectrum from the mercury gas is displayed. Due to the green filter used in the experiment only the green spectral line is visible.

STEP 3: Matching trial spectral lines to those of the actual spectrum

Manipulate the energy levels as explained in STEP 1 until the real (top) and simulated (lower) spectra match.

STEP 4: Varying the magnetic field

The strength of the magnetic field across the mercury gas tube can be varied using the slider at the bottom left of the screen. The default value is 0 Tesla and the upper limit is 10 Tesla. Varying the magnetic field will change the energy diagram and the real (top) and simulated (lower) spectra.

STEP 5: Using the zoom function

The effect of the magnetic field on the real and simulated spectra is small and you will need to use the zoom function to observe it. Directly below the simulated spectrum window is the "zoom in/zoom out" button. Click on this button to zoom in or out as required.

STEP 6: Using the polarizing film

On the right of the screen three polarizing film options are available: "No polaroid" (default), "Parallel to E" and "Perpendicular to E". With the choice "No Polaroid" 9 lines are visible. Only the three lines with photons parallel to the electric field are visible with the choice "Parallel to E". The remaining six lines with photons perpendicular to the electric field are visible with the choice "Perpendicular to E".

Direct comments to: Chandima Cumaranatunge (programming aspects); Dean Zollman (physics content).