40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Sun May 2 13:04:51 2010, Koji, Summary, SUS, Coil Actuator Balancing and Spot Position coil_balance.png
    Reply  Sun May 2 15:38:12 2010, rana, Summary, SUS, Coil Actuator Balancing and Spot Position 
       Reply  Sun May 2 16:52:44 2010, Koji, Summary, SUS, Coil Actuator Balancing and Spot Position 
Message ID: 2866     Entry time: Sun May 2 16:52:44 2010     In reply to: 2865
Author: Koji 
Type: Summary 
Category: SUS 
Subject: Coil Actuator Balancing and Spot Position 

Yes, of course. But so far I am trusting that the coils are inheretly balanced.
Probably you are talking about the dependence of the nodal position on the frequency...I need to check if 18Hz is sufficiently high or not for 0.1mm precision.

Also I am practicing myself to understand how I can adjust them by which screws as we probably have to do this adjustement many times.
(i.e. removal of the MZ, move of the table, PSL renewal and so on)

For the actuator calibration, we may be able to calibrate actuator responses by shaking them one by one while reading the OPLEV P/Y signals.

 

Quote:

 Oh, but it gets even better: in order to trust the A2L script in this regard you have to know that the coil driver - coil - magnet gain is the same for each channel. Which you can't.

But we have these handy f2pRatio scripts that Vuk and Dan Busby worked on. They use the optical levers to balance the actuators at high frequency so that the A2L gives you a true spot readout.

But wait! We have 4 coils and the optical lever only gives us 2 signal readouts...

 

ELOG V3.1.3-