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Entry  Thu Feb 28 02:43:49 2013, yuta, Update, LSC, some qualitative evidence of PRMI sideband lock PRMIsideband.png
    Reply  Thu Feb 28 03:25:27 2013, yuta, Update, LSC, PR gain ~ 25 from PRMI carrier lock PRMIcarrier.png
       Reply  Thu Feb 28 03:41:31 2013, Koji, Update, LSC, PR gain ~ 25 from PRMI carrier lock 
       Reply  Sat Mar 2 05:53:15 2013, yuta, Update, LSC, stable lock of PRMI LSCMICHOLTF_PRMI.pngLSCPRCLOLTF_PRMI.pngPRMtoAS55REFL55.png
          Reply  Sat Mar 2 14:52:02 2013, rana, Update, LSC, stable lock of PRMI 
             Reply  Sun Mar 3 22:16:46 2013, Jenne, Update, LSC, LSC whitening triggering started 
                Reply  Mon Mar 4 09:55:33 2013, rana, Update, LSC, LSC whitening triggering started 
                Reply  Tue Mar 5 18:36:27 2013, Jenne, Update, LSC, LSC whitening triggering started 
Message ID: 8197     Entry time: Thu Feb 28 03:25:27 2013     In reply to: 8196     Reply to this: 8198   8212
Author: yuta 
Type: Update 
Category: LSC 
Subject: PR gain ~ 25 from PRMI carrier lock 

[Manasa, Yuta]

We locked PRMI in carrier. Measured power recycling gain was ~25.

Plot:

  Here's some plot of PRC intra-cavity powers and MICH,PRCL error signals. As you can see from POPDC, cavity buildup was about 400, which means power recycling gain was ~25. Power recyling gain is fluctuating up to ~45 during lock. We need some gain normalization or something.
PRMIcarrier.png


Movie:

  Here's 30 sec movie of AS, POP, REFL when acquiring PRMI carrier lock. Although there's oscillation when acquiring lock, beam spot motion is less and stable compared with the past(before flipping PR2).



Locking details:
 == PRMI carrier ==
  MICH: AS55_Q_ERR, AS55_PHASE_R = -12 deg,  MICH_GAIN = -0.1, feedback to ITMX(-1),ITMY(+1)
  PRCL: REFL55_I_ERR, REFL55_PHASE_R = 70 deg, PRCL_GAIN = 5, feedback to PRM


Next:
  - Better filters and gains for stable lock
  - Kakeru method to measure g-factor (see elog around #1434)
  - OSA to measure g-factor

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