Bose-Einstein condensation of atomic hydrogen

The recent creation of a Bose-Einstein condensate of atomic hydrogen has ad ded a new system to this exciting field, The differences between hydrogen a nd the alkali metal atoms require other techniques for the initial trapping and cooling of the atoms and the subsequent detection of the condensate. T he use of a cryogenic loading technique results in a larger number of trapp ed atoms. Spectroscopic detection is well suited to measuring the temperatu re and density of the sample in situ. The transition was observed at a temp erature of 50 mu K and a density of 2 x 10(14) cm(-3). The number of conden sed atoms is about 10(9) at a condensate fraction of a few percent. A peak condensate density of 4.8 x 10(15) cm(-3) has been observed.