Efficient magneto-optical trapping of a metastable helium gas F. Pereira Dos Santos, F. Perales, J. Léonard, A. Sinatra, J. Wang, F. S. Pavone, E. Rasel, C. S. Unnikrishnan and M. Leduc Eur. Phys. J. AP, 14 1 (2001) 69-76 Published online: 15 April 2001 DOI: 10.1051/epjap:2001140