We have produced a Bose-Einstein condensate of metastable helium (He*4) containing over 1.5× 107 atoms, which is a factor of 25 higher than previously achieved. The improved starting conditions for evaporative cooling are obtained by applying one-dimensional Doppler cooling inside a magnetic trap. The same technique is successfully used to cool the spin-polarized fermionic isotope (He*3), for which thermalizing collisions are highly suppressed. Our detection techniques include absorption imaging, time-of-flight measurements on a microchannel plate detector, and ion counting to monitor the formation and decay of the condensate. © 2006 The American Physical Society.
|Article number||031603 (R)|
|Journal||Physical Review A. Atomic, Molecular and Optical Physics|
|Publication status||Published - 2006|