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I found that the ETMX F0 and F1 GAS control got saturated.
- There was a sudden but continuous drop in the control outputs (see the left figure below).
- The drop started at different moments by about 6h 30min in F0 and F1.
- I could not find any activity logs corresponding to this events.
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The net height variation of the BF with respect to the chamber in this 1 week is ~ +50 um (see the right figure below).
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There were two components contributing to this height variation.
- 1. Gradual drift (due to the temperature fluctuation?)
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2. Sudden jump at the moment of the maintenance work (with
SAFEstate) - Both are caused by the saturation (absense) of the control in F0 and F1 GAS.
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There were two components contributing to this height variation.
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Now I temporarily put setpoint values on the F0 and F1 GAS DC control to compensate the saturation.
- In return for that, the height of the BF has increased: +50 um ---> + 105 um
- I believe it could not affect that much in the payload performance (oplev centering, DRIVEALIGN, etc...) ...maybe
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To compensate the DC control outputs in a correct way, I want to offload them with fishing rods.
- I already put the task into the planner.
- But I feel this work would be less prior than other commissioning tasks, so its time slot can be rearranged.
