A high flux of ultra-cold chromium atoms in a magnetic guide

Abstract

We report the observation of a very high flux of ultra-cold bosonic chromium atoms in a magnetic guide. The beam is created by operating a magneto-optical trap/moving optical molasses within the magnetic field of the guide. A relative detuning between two pairs of the cooling lasers cools the atoms into a frame moving along the axes of the guide. When the atoms are cooled into a moving frame with a velocity of 6 m s−1 we observe a maximum of the flux of 6 × 109 atoms s−1. For these parameters the transversal temperature of the atoms after a 25 fold increase of the confining magnetic potential is about 1.2 mK. The longitudinal temperature is 400 µK.

Multichannel effects near confinement-induced resonances in harmonic waveguides

“…First, one would have to take into account the velocity distribution (distribution over the collision energy E ) in the longitudinal direction [20]. Shifts and splittings of the CIR due to anharmonicities of the trap [13,14] and the influence of the inelastic channel of molecule formation have also to be determined.…”

Evaporation-limited loading of an atomic trap

“…The theoretical curves (solid lines) are based on the numerical integration of Eq. (24). The set of coupled differential equations require three starting values: N 0 , E ρ,0 , and E z,0 .…”

“…In Eqs. (24) to (26) the first terms on the right-hand side vanish. γ is smaller than during the loading process.…”

“…The first terms on the right-hand side of Eqs. (24) through (26) describe the loading process. Particles are inserted into the trap at a loading rate L, a mean kinetic energy of¯ L,z axially and¯ L,ρ radially.…”

“…II we first describe briefly the experimental procedure used and discussed in detail in Refs. [23][24][25][26]. We develop a rate equation model for the loading process in Sec.…”