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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BGauss<br />
0.5 0.4 0.3 0.2 0.1 0.0zm<br />
Figure 7.13: Measured Zeeman slower field profile. The ideal beam profile (black) <strong>and</strong><br />
the expected profile (grey) are compared <strong>to</strong> experimental data (blue).<br />
a<strong>to</strong>m numbers.<br />
Dur<strong>in</strong>g the experiment the Zeeman slower does not run cont<strong>in</strong>uously, but turns on<br />
only for one <strong>to</strong> two seconds dur<strong>in</strong>g each experimental cycle. It is therefore not necessary<br />
<strong>to</strong> cool the Zeeman slower coils. However, dur<strong>in</strong>g the alignment procedure the Zeeman<br />
slower is frequently run at a larger duty cycle. In order <strong>to</strong> avoid overheat<strong>in</strong>g of the<br />
Zeeman slower coils, an <strong>in</strong>terlock system is <strong>in</strong>stalled that will au<strong>to</strong>matically shut-off the<br />
current if the temperature of the coils exceeds 65 ◦ C. It also limits the time the Zeeman<br />
slower can be run cont<strong>in</strong>ously <strong>to</strong> 15 m<strong>in</strong>utes.<br />
The current <strong>to</strong> the Zeeman slower is provided by two separate power supplies.<br />
Coils 1-7 are driven by a Sorensen power supply (DCR40-35A), the current <strong>to</strong> coil 8 is<br />
provided by a Kepco power supply (36-15M). To improve the current stability, a PID<br />
current controller regulates the current [68]. In addition this current controller is TTL-<br />
controlled by the computer control program, so that the current <strong>to</strong> the Zeeman slower<br />
coils can be turned on <strong>and</strong> off remotely.<br />
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