Ultracold collisions in atomic strontium
Nagel, Sarah B.
Killian, Thomas C.
Doctor of Philosophy
In this work with atomic Strontium, the atoms are first laser cooled and subsequently trapped, in a MOT operating on the strong E1 allowed transition at 461 nm. During the operation of this blue MOT, a fraction of the atoms decay into the 3P2 and 3P1 states, but can be recovered by applying light from repumper lasers at 679 nm, and 707 nm. Atoms trapped in the blue MOT are subsequently transferred into a magneto-optical trap operating on the intercombination line at 689 nm, known as the red MOT. Photoassociation experiments are carried out on these atoms using an independent tunable source of blue light at 461 nm. These experiments map out the underlying molecular potentials, and are useful in determining the atom-atom interaction strength. Additionally, atoms trapped in the red MOT can be transferred into an optical dipole trap (ODT) operating at 1064 nm, resulting in a cold dense sample suitable for collision studies, lifetime measurements, and evaporative cooling towards Bose-Einstein condensation.