How to Repump the Coralie Fabry-Perot
- In general the Coralie Fabry-Perot has to be let alone as much as possible.
The decision to re-pump it should be decided by the scientific / technical team only. In particular this action might induce a discontinuity in the measurements of Coralie.
- In normal conditions, the pressure will increase at a rate that has to be below ~ 2e-3 mBar / day.
- If the pressure is below 3 mBar and the increase rate is ok there is no reason to repump the system.
- Doing the pumping imply to enter the Coralie thermal enclosure thus care has to be taken to let enough time before observations for Coralie to stabilize (maybe 2 days).
!!!!! Warning, in the Coralie thermal enclosure the path to the Fabry-Perot cryostat passes close to the Coralie fiber optics. It is therefore necessary to take extreme care when moving in this room.!!!!!
The material needed to connect the pump to the FP can be found in the bodega and the maintenance cabinets
- Bring the Necam pumping system located at the telescope level, into the Bodega with a DN40 interface and connect it to the FP : To do so one has to make the pumping tubes pass trough the wall of the bodega up to the coralie thermal enclosure in via a hole in the wall
- Close check that the FP valve is closed
- Open the pump valve
- Start the pump (the pump is an automatic pump that deals alone with starting the primary and secondary pump). There is a gauge on the side of the pump.
- Slowly open the FP valve when and only when the pressure in the pump is below the one in the FP. The FP gauge is located on the roof (right side) of the coralie thermal enclosure. One need a ladder
- Once the valve open, let the pump running for 2 hours
- If the pressure is again in the 1e-3 1e-4 regime
- Close all valves
- Stop the pump.
- Disconnect everything
- Close the Coralie Enclosure
The material needed to connect the pump to the FP can be found in the bodega and the maintenance cabinets
