Reports until 16:53, Friday 20 October 2017
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 16:53, Friday 20 October 2017 (39111)
First re-suspended H1 SUS ITMY Top-to-Top TFs: Main Chain rubbing on Reaction Chain, Reaction Chain Locked up
J. Kissel

We figured we'd close out the successful week of H1 SUS ITMX re-installation by checking the overall health / freedom of the suspension with the usual top-to-top transfer functions for both M0 and R0. Sadly, we wasted our luck on detection a loud binary neutron star collision a few months ago. The Main Chain shows evidence of interference with the reaction chain, or some otherwise subtle rubbing in the middle stages. The reaction chain is virtually locked up. I won't both posting the full detailed results, but I do attach some DTT sample degrees of freedom. The BLACK traces are the reference from the former suspension, in vacuum, back in July. The RED traces are the current response.

This is by no means un-expected, nor is it a show stopper. We still have to *at least*
   - Re-align the reaction chain to the *correct* spots (see LHO aLOG 39109) 
   - Align / center the UIM flags / OSEMs
   - Re-align / center the PUM flags / OSEMs
   - Measure main-chain violin modes, then remove that temporary infrastructure
which all require gross mechanical work that will change the rubbing situation.

We'll slowly begin to address this all next week.
Images attached to this report