Weekly SUS Meeting
Agenda & Summary Notes from July 22, 2008
Adv LIGO Suspension wiki: http://ilog.ligo-wa.caltech.edu:7285/advligo/Suspensions
Every Tuesday at 9am Pacific/Noon Eastern/4pm UK
1 LASTI/SEI/SUS schedule coordination discussion
a) noise development: I) mechanical, II) monolithic stage
b) osem & electronics
3 BS & FM
4 RM & IMC
1 Norna, Calum, Jay, Mark Caltech
2 Ken Glasgow
4 Justin, Amanda, Joe RAL
5 Brett, Alastair, Rich MIT
6 Luke Florida
7 Ron, Stuart Birmingham
8 Mike, Derek, Janeen LLO
9 Betsy, Vern, Doug, Gerardo LHO
SUMMARY NOTES AND ACTIONS FROM THIS MEETING
1 SUS/ISI LASTI/SEI/SUS Schedule Coordination Discussion
Brett said that his quad alignment document is almost finished. He plants to switch over to modal damping after this. Norna asked Brett to do some measurements
Fabrice made robust filters, to keep an eye on the quad wandering structure modes. Is the amount of wandering a concern? The initial controller had notches. These notches
were made larger to deal with the wandering modes. There was no good data after venting. Robust filters impact performance. Could peaks be related to controls
algorithms of the osems? Brett answers probably not. It rolls off as you'd expect it to for the structure. Concerning the performance degradation due to the robust filtering,
the upper unity gain frequency of 20-30 Hz is aggressive. Fabrice backed off to 20 Hz, which is timid and the gain is proportional. Rich said that they might get
some back by fine tuning the filters. If someone can track these wanderings over time, the filters could be fine tuned.
Amanda reports that they placed the order for the blades. They'll receive the material in 2 weeks. The blades will be rolled.
Alastair has finished putting together the articulated arm and done some test welds on the bench. Ideally, they'd have more power going through for welding and pulling
and they might consider buying a slightly more powerful laser for this. They set up the strength tester and done some testing with it. They've done some fiber annealing.
Alastqair is in discussions with Giles on a pre-annealing specification.
In Glasgow, they're refining the details of the tooling and procedure for taking the fiber out of the machine, measuring and moving it. Parts are all sent or
ready to be sent to MIT. The projected date for the test assembly is near mid-August.
Electronics and Osems
Stuart reports that they received some flexi-circuits. He got some fixtures in for doing noise measurements on in-air and in-vacuum osems with the sleeve in.
Ron reports that the UIM board is in manufacture. The top board should go out tomorrow for manufacture. He received Jay's small triples electronics requirements document.
Norna mentioned that she and Dennis looked at the osems and channel counts. They've changed due to the stable recycling change. Look at the M030162, addendum 2,
column 2 for Auxilliary optics. You'll notice the the UK is not providing electronics for the auxilliary suspensions (the SOSs.)
3 BS & FM
Joe's been starting to address the BS assembly documents. His next step is to write up the full assembly. He's designed in some stiffening members to the BS structure
and given the model to Tim Hayler for FEA.
Norna asked if the beamsplitter optic should have a grooves in it for the wires. Joe does not have it in his metal mass. Ken said that there is no suspension requirement
for the grooves. The groove itself doesn't affect whether you need 2 breakoffs. It should be a thermal noise issue. It should be acceptable either way.
Justin will send around some notes.
4 RM & IMC
Concerning the IMC (HAM small triple suspension) PDR, David wants an overarching document to provide an overview/summary.
The LHO OMC SUS should ship tomorrow from Caltech to Hanford. It should arrive in less than a week. The boxes will be addressed to Mike Landry, but Betsy will keep her eyes open.
Doug suggests Derek & Chris e-mail him now for visitor forms.
Agenda for 29 July 2008
1. LASTI / SEI / SUS schedule coordination discussion
a) noise development
2. monolithic stage
b) osem and electronics development
3. BS & FM - grooves on the optic or not?
4. RM & IMC