Abstract. We demonstrate experimentally the continuous and pulsed loading of a slow and cold atomic beam into a magnetic guide. The slow beam is produced using a vapor loaded laser trap, which ensures twodimensional magneto-optical trapping, as well as cooling by a moving molasses along the third direction. It provides a continuous flux larger than 10 9 atoms/s with an adjustable mean velocity ranging from 0.3 to 3 m/s, and with longitudinal and transverse temperatures smaller than 100 µK. Up to 3 10 8 atoms/s are injected into the magnetic guide and subsequently guided over a distance of 40 cm.

We study theoretically a scheme in which particles from an incident beam are trapped in a potential well when colliding with particles already present in the well. The balance between the arrival of new particles and the evaporation of particles from the trapped cloud leads to a steady-state that we characterize in terms of particle number and temperature. For a cigar shaped potential, different longitudinal and transverse evaporation thresholds can be chosen. We show that a resonance occur when the transverse evaporation threshold coincides with the energy of the incident particles. It leads to a dramatic increase in phase space density with respect to the incident beam.

In this article we focus on the propagation of a beam of particles guided by a transversely confining potential. We consider different regimes. In the classical regime, we describe the beam by means of a set of hydrodynamic-like equations. We apply this formalism in order to investigate two practical ways for increasing the collision rate: by using a constriction or by tilting the guide. A high enough collision rate is indeed the most crucial prerequisite for reaching the quantum degenerate regime by means of evaporative cooling. In the quantum regime, we study the propagation of bosonic atoms through a constriction in two opposite regimes: the collision-less one and the Thomas-Fermi one.