40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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Entry  Wed Feb 20 01:40:37 2013, Manasa, Update, Alignment, Final IFO alignment- in progress 
    Reply  Wed Feb 20 03:13:10 2013, yuta, Update, Alignment, clipping centering checklist ClippingCenteringChecklist.pdf
       Reply  Wed Feb 20 20:58:37 2013, yuta, Update, Alignment, clipping centering checklist ClippingCenteringChecklist.pdf
          Reply  Wed Feb 20 21:12:37 2013, rana, Update, Alignment, clipping centering checklist 
             Reply  Wed Feb 20 21:56:08 2013, yuta, Update, Alignment, clipping centering checklist 
    Reply  Wed Feb 20 10:13:41 2013, yuta, Update, Alignment, PRC flashing brighter than last week 
Message ID: 8115     Entry time: Wed Feb 20 10:13:41 2013     In reply to: 8113
Author: yuta 
Type: Update 
Category: Alignment 
Subject: PRC flashing brighter than last week 

After in-vac alignment work last night, PRC is flashing brighter than PRMI alignment last week.
My hypothesis is that "we aligned PRM to junk MI fringe last week". Possibly, we used MI fringe caused by AR reflection of ITMs, or MI fringe reflected from SRM.

Videos:
  PRC flashing last week (youtube, elog #8085, elog #8091)

  PRC flashing this time (Lens in-front of AS camera was taken out)



My hypothesis can explain:
 - why we had dimmer POP last week (flash in half-PRC was way brighter even when we had more attenuators (youtube))
 - why I thought AS55 is broken (AS was too dim)

Conclusion:
  Be careful of junk beams.

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