Experiments to Control Atom Number and Phase-Space Density in ...

Chapter 4
Rubidium Apparatus
A modern atomic physics experiment, even the table-top experiment, requires a
large number of different technological equipment, electronics, optics and vacuum. All
of these elements have to work simultaneously. It is therefore a challenge to design
a system in such a way that it runs reproducibly and reliably. This chapter gives an
overview of the experimental apparatus used in the single-photon cooling experiment.
Details about the construnction of the setup can be found in [67–70].
4.1 Vacuum System
The vacuum system is designed for the experiment to operate in the double MOT
configuration [71]. In this configuration a low background pressure is maintained in the
science chamber (where the experiments are performed, in this setup the lower chamber),
while rubidium atoms can quickly be accumulated in the MOT in an upper chamber,
where the background pressure is higher. These two chambers are interconnected by a
differential pumping tube that maintains the pressure differential while at the same time
allowing for the accumulated atoms to be passed from one chamber into the other. A
photograph of the rubidium vacuum chamber is shown in figure 4.1.
4.1.1 Upper Chamber
The upper chamber consists of a Pyrex glass cell with outer dimensions 4 in ×
1.25 in×1.25 in connected to a 2-3/4 CF stainless steel flange through a graded glas-
to-metal seal (Larson Electronics Glass Inc, SQ-150-F2). A 6.75 in long stainless steel
tube with a tapered hole (diameter between 1/8 in at the top and 3/8 in at the bottom)
serves as differential pumping tube and allows the atoms to be transferred from the
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