  An apparatus for producing atomic-gas Bose-Einstein condensates (BECs) of
87-Rb atoms is described. The apparatus produces 87-Rb BECs in a dual-chamber
vacuum system that incorporates magnetic transport of trapped atoms from the
magneto-optical trapping cell to the BEC production cell via the operation of a
series of overlapping magnet coils. The design, construction, and operation of
the apparatus are described in detail. The apparatus is used to study the
creation of quantized vortices in BECs by the merging and interference of
multiple trapped condensates. In this experiment, a single harmonic potential
well is partitioned into three sections by an optical barrier, enabling the
simultaneous formation of three independent, uncorrelated BECs. The BECs may
either merge together during their growth, or, for high-energy barriers, the
BECs can be merged together by barrier removal after their formation. Either
process may instigate vortex formation in the resulting BEC, depending on the
initially indeterminate relative phases of the condensates and the merging
rate.
