Kendall B. Davis

An analytical model for evaporative cooling of atoms

Evaporative cooling of trapped atoms is described as a sequence of truncation of the high-energy tail of the thermal distribution followed by collisional relaxation. This model is solved analytically for arbitrary power-law potentials. The threshold density for accelerated evaporation is. found to be lowest in a three-dimensional linear potential.

BOSE-EINSTEIN CONDENSATION OF ULTRACOLD ATOMIC GASES

Bose–Einstein condensation in a dilute gas of sodium atoms has been observed. The atoms were trapped in an optically plugged magnetic trap or in a cloverleaf magnetic trap. Rf induced evaporative cooling increased the phase-space density by six orders of magnitude. We summarize the different techniques used, and discuss recent studies of properties of Bose condensates with an outlook on future developments.

Bose-Einstein Condensation in a Gas of Sodium Atoms

We have observed Bose-Einstein condensation of sodium atoms. The atoms were trapped in a novel trap that employed both magnetic and optical forces. Evaporative cooling increased the phase-space density by 6 orders of magnitude within seven seconds. Condensates contained up to 5 3 105 atoms at densities exceeding 1014 cm23. The striking signature of Bose condensation was the sudden appearance of a bimodal velocity distribution below the critical temperature of , 2 mK. The distribution consisted of an isotropic thermal distribution and an elliptical core attributed to the expansion of a dense condensate.