arXiv subjects

Dale G. Fried

Publications and source records attributed to Dale G. Fried.

3 recordsLinked to original sources

arXiv1999

Bose-Einstein Condensation of Atomic Hydrogen

This thesis describes the observation and study of Bose-Einstein condensation of a trapped, dilute gas of atomic hydrogen. The condensate and normal gas are studied by two-photon spectroscopy of the 1S-2S transition. We condense over 10^9 atoms per second for several seconds, and the peak condensate density is around 5x10^15 cm^-3. Topics covered in the thesis include a theoretical analysis of Bose-condensed hydrogen, a description of the cryogenic trapping cell and the evaporative cooling techniques used to bring the gas to the condensation point, and an analysis of the condensate.

physics.atom-ph↗

arXiv1998

Bose-Einstein Condensation of Atomic Hydrogen

We have observed Bose-Einstein condensation (BEC) of trapped atomic hydrogen, and studied it by two-photon spectroscopy of the 1S-2S transition. In these lecture notes we briefly review the history of spin-polarized atomic hydrogen and describe the final steps to BEC. Laser spectroscopy, which probes the difference in mean field energy of the 1S and 2S states, is used to study the condensate, which has a peak density of 4.8e15 cm^-3 and population of 10^9.

physics.atom-ph↗

arXiv1998

Bose-Einstein Condensation of Atomic Hydrogen

We report observation of Bose-Einstein condensation of a trapped, dilute gas of atomic hydrogen. The condensate and normal gas are studied by two-photon spectroscopy of the 1S-2S transition. Interactions among the atoms produce a shift of the resonance frequency proportional to density. The condensate is clearly distinguished by its large frequency shift. The peak condensate density is 4.8 +/- 1.1 \times 10^{15} cm^{-3}, corresponding to a condensate population of 10^9 atoms. The BEC transition occurs at about T=50 uK and n=1.8 \times 10^{14} cm^{-3}.

physics.atom-ph↗