2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/102671We have produced a Bose-Einstein condensate of metastable helium (4He*) containing over 1.5x10^7 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 (3He*), 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.4 pages, 3 figures (changed content)Other Condensed MatterA Large Atom Number Metastable Helium Bose-Einstein Condensatetext