Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Physics and Astronomy Dept.


Charles Conover


We report measurements of the quantum defect for the f-, g-, and h-states of potassium with principal quantum number n between 26 and 29. Ground state potassium atoms in a magneto-optical trap are excited from the 4s state to the 5p state, then from the 5p state to the ndj state using lasers at 405nm and 980nm, respectively. We then measure the millimeter wave frequencies of the ndj to nl transitions. We extract the quantum defects from these frequency measurements in conjunction with the known d-state quantum defects. Experimental challenges with fully canceling the electric field and the inhomogeneity of the electric field inside the magneto-optical trap lead to our greatest sources of uncertainty. Our measurements show significant disagreement with predicted values that are calculated from the theoretical dipolar and quadrupolar polarizabilities of potassium.


Quantum Defect, Rydberg Atoms, Potassium, Core Polarizability, Stark Shift, Magneto-Optical Trap