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  Thu Sep 4 01:28:32 2014, ericq, Update, LSC, Recycling cavity lengths 
    Reply  Thu Sep 4 10:10:23 2014, Koji, Update, LSC, Recycling cavity lengths 
       Reply  Thu Sep 4 18:16:20 2014, ericq, Update, LSC, Recycling cavity lengths 2014-09-CavityLengths.zip
Message ID: 10453     Entry time: Thu Sep 4 18:16:20 2014     In reply to: 10451
Author: ericq 
Type: Update 
Category: LSC 
Subject: Recycling cavity lengths 

Koji correctly points out that I naïvely overlooked various factors. With a similar analysis to the wiki page, I get:

  • Ideal arm length of 37.795 m
  • Ideal PRC length of 6.753 m
  • Ideal SRC length of 5.399 m

This means that:

  • The PRC, measured at 6.759m, is 6mm long. 
  • The SRC, measured at 5.474m, is 7.5 cm long

Next step is to see how this may affect our ability to sense, and thereby control, the SRC when the arms are going. 

MIST simulations and plots are in the attached zip. 

Attachment 1: 2014-09-CavityLengths.zip  2.325 MB
ELOG V3.1.3-