Collisional Studies of Ultracold Cesium

Citation

Bliss, Joshua Lovis (1999) Collisional Studies of Ultracold Cesium. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/fcz4-pd11. https://resolver.caltech.edu/CaltechTHESIS:07252025-144149295

Abstract

Spin-polarized neutral cesium atoms are confined in a magnetostatic trap in a cryogenic apparatus. The atoms are prepared in the F = 4, m_F = 4 state and cooled, with rf-assisted evaporative cooling, to less than 10 microKelvin.

The elastic scattering cross section is measured by disequilibrating magnetostatically trapped atoms and observing the rate of equilibration. A computer simulation is presented, the results of which are used to extract the elastic scattering cross section from the measured rates of equilibration. For cesium atoms in the F = 4, m_F = 4 state, the elastic cross section is confirmed to have a resonant magnitude which varies inversely with the mean kinetic energy, implying a scattering resonance.

A design for a new beam source of cold neutral atoms, based on an optical funnel with a pyramid mirror configuration, is also presented.

Thesis Files