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Entry  Fri May 1 01:49:55 2020, gautam, Update, ALS, ASY commissioning 
    Reply  Fri May 1 22:44:17 2020, gautam, Update, ALS, ASY M2 PZT damaged 
       Reply  Sat May 2 02:35:18 2020, Koji, Update, ALS, ASY M2 PZT damaged 
Message ID: 15315     Entry time: Fri May 1 01:49:55 2020     Reply to this: 15316
Author: gautam 
Type: Update 
Category: ALS 
Subject: ASY commissioning 


It appears that the EY green steering PZTs have somehow lost their bipolar actuation range. I will check on them the next time I go to the lab for an N2 switch.


  • Yuki installed the EY green PZTs and did some initial setup of the RTCDS model. 
  • But we don't have a functional dither alignment servo yet, which is mildly annoying. So I thought I'll finally finish my SURF project.
  • There were several problems with the signal flow, MEDM screens etc.
  • I rectified these, and set up some operational scripts, burt snapshots etc in $SCRIPTS/ASY. The c1asy and c1als models were also modified, recompiled and restarted, everything appears to have come back online smoothly.
  • The LO frequencies/amplitudes, demod filter gains and demod phases were chosen to have a signal mostly in the _I quadrature of the demodulated signal when the alignment is slightly disturbed from optimal (monitored after the post-demod LPF).
  • While trying to close the integrator loops, I found that I appear to only have monopolar actuation ability (positive DAC output changes the alignment, negative DAC output does nothing).

Could be that the power outage busted something in the drive electronics. 

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