Experiments to Control Atom Number and Phase-Space Density in ...
Experiments to Control Atom Number and Phase-Space Density in ...
Experiments to Control Atom Number and Phase-Space Density in ...
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follow the master supply. This setup allows for an <strong>in</strong>crease of the output current at the<br />
cost of reduc<strong>in</strong>g the available voltage. The properties of the MOT coils are summarized<br />
<strong>in</strong> table 7.2.<br />
<strong>Number</strong> of coils 2<br />
<strong>Number</strong> of layers per coil 4<br />
<strong>Number</strong> of turns per coil 22<br />
Current through each coil 36 A<br />
Axial gradient 43.7 G/cm<br />
Radial gradient 21.9 G/cm<br />
Inner diameter of the coils 152 mm<br />
Table 7.2: Properties of the MOT coils<br />
The calculated magnetic field profiles of the MOT coils <strong>in</strong> radial <strong>and</strong> axial direc-<br />
tions are shown <strong>in</strong> figures 7.15 <strong>and</strong> 7.16. Experimental data (blue) are measured us<strong>in</strong>g<br />
a Gaussmeter.<br />
BGauss<br />
100<br />
75<br />
50<br />
25<br />
30 20 10 10 20 30zcm<br />
25<br />
50<br />
75<br />
100<br />
Figure 7.15: Radial field profile of the MOT coils. The solid l<strong>in</strong>e is the calculated field,<br />
experimentally determ<strong>in</strong>ed field strengths are shown <strong>in</strong> blue.<br />
Under normal operation the coils will not exceed a temperature of 30 ◦ C. Dur<strong>in</strong>g<br />
alignment of the MOT, when the coils are run cont<strong>in</strong>ously, the temperature of the MOT<br />
coils can, however, be quite high. Unfortunately, a heat<strong>in</strong>g of the coils is closely coupled<br />
<strong>to</strong> a heat<strong>in</strong>g of the ZnSe viewports due <strong>to</strong> their proximity <strong>to</strong> each other. To avoid any<br />
107