Realization of a magnetically guided atomic beam in the collisional regime

TL;DR

This paper reports the creation of a magnetically guided cold rubidium atomic beam with high flux and thermalization, demonstrating evaporative cooling potential towards quantum degeneracy.

Contribution

It presents the first realization of a magnetically guided atomic beam with sufficient collisionality for thermalization and evaporative cooling.

Findings

Atomic beam flux of 7×10^9 atoms/s

Temperature of 400 μK and mean velocity of 1 m/s

Evaporative cooling increases phase space density

Abstract

We describe the realization of a magnetically guided beam of cold rubidium atoms, with a flux of $7\times 10^9$ atoms/s, a temperature of 400 $\mu$K and a mean velocity of 1 m/s. The rate of elastic collisions within the beam is sufficient to ensure thermalization. We show that the evaporation induced by a radio-frequency wave leads to appreciable cooling and increase in phase space density. We discuss the perspectives to reach the quantum degenerate regime using evaporative cooling.