As in most BEC-experiments we use a combination of laser cooling, magnetic trapping and evaporative cooling to reach Bose-Einstein condensation. A beam of Rb87 atoms is decelerated by chirp-slowing and is trapped in a magneto-optical trap. After subdoppler-cooling these atoms are transferred to a purely magnetic trap, in which the BECs are produced by evaporative cooling. This technique induces spin flips of the atoms via radio frequencies such that they are transferred to substates which are magnetically untrapped. The magnetic substates are energetically shifted due to the magnetic field of the trap. Therefore it is possible to adress the radius of the cloud where the transitions occur. Starting with frequencies of 20 MHz and ramping it down to 350 kHz, it is possible to remove only the most energetic atoms and cool the whole sample. Several laser systems can be used to manipulate the BECs. In particular, an optical lattice is generated by a Titanium Saphire Laser pumped by a solid state laser (Coherent, Verdi). Additionally Bragg- and Raman-transitions can be induced using diode laser system.
