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Electronics | Mr. Freeze (dilution refrigerator) | Mrs. Astra

Principle of Operation | Cooling Down | Starting the Circulation | Warming Up |

Pumping the Transfer Tube and the Top Loading Stick | Loading and Unloading the Sample

 

n. b. This is not a foolproof guide. It is very important that one has to know what he is doing, why he is doing it, and what’s happening in Mr. Freeze if he does it.

 

PUMPING THE LOADING STICK/TRANSFER TUBE

 

  1. Connect the adapter Allen wrench to the top loading stick/transfer tube, and then to VENT 3. Make sure that the loading stick/transfer tube is in a stable position so as not to put too much mechanical stress on it.

  2. Turn on ROT A PUMP.

  3. Open 35, and turn on P3. Wait until pressure is below 10-1 mbar.

  4. Open 29.

  5. Make sure OVC valve, 21, 21A, 22, 23A, 23B, 25A, 26 and 27 are closed.

  6. Open 25B. Wait until pressure stabilizes below 10-1 mbar.

  7. Open 23B. Wait until pressure stabilizes below 10-1 mbar.

  8. Open 21A. Wait until pressure stabilizes below 10-1 mbar.

  9. Open the black valve of the adapter Allen wrench to start pumping of loading stick. Wait until pressure stabilizes below 10-1 mbar.

  10. Close 21A.

  11. Purge loading stick with air by opening VENT 3 to air momentarily, and then closing it again.

  12. Do steps 8-11 2 more times.

  13. Close 21A, 23B, 25B, and 29 in that order.

  14. Open 30.

  15. Turn on DIFF A PUMP. Open the PENNING GAUGE. Wait until pumping of the diffusion pump is stable.

  16. Open 27. Wait until pumping of the diffusion pump is stable.

  17. Open 25B. Wait until pumping of the diffusion pump is stable.

  18. Open 23B. Wait until pumping of the diffusion pump is stable.

  19. Open 21A. Pump for a few hours.

  20. Close black valve on adapter on loading stick.

  21. Close 21A, 23B, 25B, and 27 in that order.

  22. Turn on DIFF A PUMP.  Wait until the diffusion pump has cooled down to room temperature (takes maybe one hour).

  23. Close 30 and 35 in that order.

  24. Turn off ROTARY A PUMP.

  25. Turn off pressure gauges.

  26. Remove loading stick/transfer tube and return to resting position by the cryostat.

 

Updated:   August 9, 2004, Ian Jasper Agulo

 
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