Creation and Characterization of a BEC of $^{7}$Li

We have designed and built an apparatus for trapping and cooling the isotopes of Li to quantum degeneracy. Presently, $^{7}$Li atoms are first Zeeman slowed and loaded into a magneto-optical trap. The trapped cloud is cooled and compressed, magnetically polarized via optical pumping, and loaded into an electromagnetic trap. A 45 s RF evaporation is then performed, cooling the gas to 5 $\mu$K. The electromagnetic trap is switched off while a single beam optical-dipole trap is ramped on. An adiabatic RF sweep is used to transfer the population of atoms from the \textit{F}=2, m$_{F}$=2 hyperfine state to the \textit{F}=1, m$_F$=1 state, where the scattering length may be controlled by a Feshbach resonance. By tuning the scattering length to a large and positive value, evaporation proceeds efficiently below the Bose-Einstein condensation transition temperature. Quantitative information on the BEC is obtained via absorption or phase-contrast imaging of either the trapped atoms or the freely expanding cloud.