BEC in 87Rb |F=2, mF=+2>
As of July 8, 2002, BEC has been achieved in 87Rb |F=2 mF+2>. At first about 5 x 108 atoms are collected in the 2nd MOT in 30 seconds. After polarization gradient cooling, the atoms are loaded into a cloverleaf magnetic trap. The trap is adiabatically compressed over about 4 s to an axial trap frequency of 18.8 Hz and radial trap frequencies of 182 Hz. Evaporative cooling is performed with a quasi-exponential RF ramp from 30 MHz to around 1.00 MHz in 44 s, and end up with a condensate of (2.0±0.3) x 105 atoms.
Atom Species : 87Rb |F=2, mF=+2>
Pre-cooling : Double MOT (Back ground pressure : (2.4±0.4) x 10-11torr)
MT type : Cloverleaf (IP trap), (wz=2p x 18.8 Hz, wr=2p x 182 Hz)
Number of condensed atoms = (2.0±0.3) x 105
1mm x 1mm image
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1mm x 1mm image
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1mm x 1mm image
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RF = 1.02 MHz
(43.7s evaporation)
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RF = 1.01 MHz
(43.8s evaporation)
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RF = 0.99 MHz
(44.0s evaporation)
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Time of flight images are taken after 16ms along gravitational axis.
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