We report the first creation of a BEC (of metastable helium, 4He*) using buffer-gas cooling, without the use of laser cooling. 1011 4He* atoms are produced via RF-discharge and magnetically trapped at an initial temperature of 400 mK in an anit-Helmholtz quadrupole field. These atoms are evaporatively cooled into the ultracold regime and transferred to a tightly confining superconducting QUIC trap with trap frequencies omegaaxial = 2 &pi × 210 Hz and omegaradial = 2 &pi × 2500 Hz. Further cooling is achieved by driving transitions with resonant RF radiation. The transition temperature is reached at about 5 µ K with approximately 106 atoms. The cloud is detected via phase-contrast imaging at 1083 nm, either in-situ or in time-of-flight.
BEC! - report: May 22, 2009
S. C. Doret, C. B. Connolly, W. Ketterle, J. M. Doyle