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  Wed Jun 6 14:36:15 2018, gautam, Update, LSC, TRX clipping 
    Reply  Thu Jun 7 16:15:03 2018, gautam, Update, LSC, TRX clipping 
Message ID: 13927     Entry time: Thu Jun 7 16:15:03 2018     In reply to: 13920
Author: gautam 
Type: Update 
Category: LSC 
Subject: TRX clipping 

I opted for the quickest fix - I raised the height of the offending steering mirror using a 0.25" shim. In the long term, we can get a taller post machined. After raising the mirror height, I then checked the DC centering of the spot on the DC PD using a scope.

Looking at the performance of the X arm ASS, I no longer see the strange oscillatory behaviour I described in my previous post yes. Moreover, the TRX level was ~1 before be raising the steering mirror - but it is now ~1.2. So we were certainly losing some power.

ELOG V3.1.3-