Procedure power failure FELICE molecular beam instrument

This walkthrough will help you to re-start the intracavity part of the instrument; pumping the source chambers is not necessary.

Venting the machine completely in preparation of a power outage

1. switch off all pressure gauges on the Pfeiffer Maxigauge in the 19" rack
2. Close the valve between forepump and turbopump of the 35 source chamber (hand valve at the front of the setup, at the far right)
3. Close the valve between forepump and turbopumps of the intracavity and differential chambers (all hand valve on the manifold at the back of the setup)

   

   only intracavity valve open

4. Vent all turbopumps using the BESTEC PC in the 19" rack

   

   top left

5. Once vented

• switch of all power supplies P1-P7 in the bottom of the 19" rack

only intracavity valve open

• shut down the Bestec PC
• switch off Pfeiffer maxigauges
• switch off the mains of the 19" rack

top left

• switch off forepumps (you have to enter in the space under the staircase, close all valves, and flip the power switches)

When power is out (uncontrolled venting)

1. In case of a power outage, and the power is still down, switch off the main power of the Bestec 19" rack.
   

   

   top left
2. Switch off power supplies P4, P5, P6 and P7 in the bottom of the 19" rack (power switches on the back).
   

   

   only intracavity valve open
3. The rotary vane (see next point) should be vented. To do this, the valve in front of the pump ( green one) should be closed and the bellows piping should be disconnected.

When power comes back

1. Check the two fore vacuum pumps under the stairs: the scroll pump should start automatically when power comes up, the rotary vane will stay off (keep it that way).

   

   left is the scroll pump

2. Ensure that the fore vacuum line is only open toward the intracavity turbo pumps.

   

   only intracavity valve open

3. Switch on the main power of the Bestec 19" rack.

   

   top left

   The PC should start automatically, and spawn the vacuum control program (shortcut on desktop)

4. Ensure pumps P1, P2 and P3 start have started automatically (they should show yellow, indicating a rising pump speed).

   If not: start them by left-clicking either of the pumps and select "start" in the popped-up window; Then close the window.

   (Usually, starting one will also start the other two, but this sometimes fails. To be sure, start each one explicitly).

   (If pump stays red, displaying 0 Hz, communication may have failed. Cycling the power supply frequenly helps).

5. If you have not switched off the power supplies (in the "when power is out section"): stop pumps P4, P5, P6 and P7.

   

   top left

6. Pressures on G1, G2 and G3 should rapidly drop to 10^-5, the foreline pressure is G8, it should be 10^-2–0.1 mbar
7. Contact Joost at +31 6 4412 6316 or Olga at ...