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Here are instructions for cooling the SONIC

Guest on 24th April 2022 08:17:25 AM

  1. Here are instructions for cooling the SONIC.
  2. 1. Attach vacuum valve to pump, start pump.  When pressure on-scale
  3. on gauge, open dewar valve.  Wait until pressure is below 5x10^-4;
  4. below 2x10^-4 is even better.
  5.  
  6. 2. Attach helium hoses to cooler if not already done.  Note order
  7. specified on cold head.
  8.  
  9. 3. Find a 12 volt power supply, Vac-ion power supply, the 4-pin
  10. connector with two orange wires coming out, and the bias cable (19
  11. pin connector on one end, D-15 plus 4-pin plug on the other).  If you
  12. want to monitor temperatures during the cooldown and don't have the
  13. camera electronics, also find the adaptor with D-15, D-9, and round
  14. 26-pin socket all wired together.
  15.  
  16. 4. Start the compressor.  Make sure the water valve is plugged in and
  17. that cold water is flowing in the compressor.  In cold weather, the
  18. compressor is hard to start.  Let it run 10 seconds, then stop for 10
  19. seconds, then 20 seconds, etc.  Soon it should be running continuously.
  20.  
  21. 5. Attach the bias cable to the dewar.  Plug the 4-pin connector into
  22. the socket with the orange wires, connect the orange wires to the
  23. power supply, turn on supply, and set to 12 volts.  Check that the
  24. current is approximately 110 mA.
  25.  
  26. 6. To monitor temperature, turn on temperature controller and attach
  27. to dewar.  This can be either via the plug on the camera electronics
  28. or via the "three-connector adaptor."  If using the latter, plug the
  29. bias cable from the dewar into the D-15 on the adaptor.  The round
  30. plug on the adaptor goes to the dewar, and the D-9 goes to the
  31. thermometer cable on the DRC-91 temperature controller.  Channel A2
  32. is the detector block, A4 is the cold shield.  The temperature of A2
  33. should never change faster than 1 degree per minute.  Following these
  34. instructions should ensure that.
  35.  
  36. 7. When the temperature of A2 has dropped to approximately 150 K, it
  37. should be possible to plug in the Vac-Ion.  This will be 3-5 hours
  38. after the cooler is started.  After another hour or two, when the
  39. temperature has dropped to 120 K or so, it should be possible to
  40. close the vacuum valve.  The valve will need to be closed and
  41. reopened a couple of times to clear out air trapped in the valve
  42. itself.  Make sure the Vac-Ion pump stays on-scale with the valve
  43. closed.  When it does, the vacuum pump can be stopped and
  44. disconnected.
  45.  
  46. 8. When temperature A2 is below 100 K, the power supply voltage can
  47. be reduced to 6 V.  After half an hour at 6 V, the power supply can
  48. be disconnected if desired.  Or it can be left at 12 volts as long as
  49. you like.

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