J. Kissel, B. Weaver, M. Landry, S. Biscans, C. Remet H. Radkins, T. Vo, B. Gateley *phew* The last known in-chamber payload suspect in the misdemeanor seen earlier with the ISI-ITMX vertical transfer functions was the teflon rails that were temporarily installed on the SUS-ITMX for first-contact cleaning. So, Betsy and I went out and removed them. Preliminary measurements (attached below) indiciate these were the problem, the ISI looks fine now. We are a go for final cleaning and close up of BSC3 (as agreed by all those listed above). In the next half hour that it takes me to finish writing this aLOG, Sebastien is going to get a few more transfer functions just to be sure we're OK, but Celine (from afar) has been watching the story, and has informed us that she had seen similar badness when she had taken ISI transfer functions with the QUAD locked (with EQ stops), so we 100% confident that things have been restored to goodness already. To repeat for clarity, - It wasn't the dome installation that caused the badness - It wasn't the arm cavity baffle's eddy current dampers or mechanical rubbing - It wasn't the in-chamber cabling It was 300 kg of mass (the suspended elements of the QUAD) that had been temporarily locked up with teflon rails for the (new, yet) normal first contact routine. -------- Plot Caption: [[ISI-ITMX, Stage 0-1 Actuator drive, Stage 1 CPS sensor response, driven transfer function. HEPI is floating and balanced, ISI is floating and balanced, ISI control is entirely OFF, ACB is freely suspended and Eddy-current Damped, SUS-ITMX is freely suspended with main and reaction chain locally damped with top-stage OSEMs]] BLACK Known good reference measurement taken over Tuesday-to-Wednesday (2013-Nov-19 to 20) night. BLUE The bad state the ISI has been since measuring quickly Wednesday afternoon, after Teflon rails are installed, QUAD is first-contact painted, ACB is B&K hammered Dome is installed ACB is re-inspected ISI and other in-vac cabling is inspected (from underneath the ISI) RED Now good, current measurement, after Betsy removed the temporary teflon rails.
Just to confirm what Jeff said: I took a few more quick transfer functions (ST1, ST2, vertical, horizontal), and everything looks back to normal (the teflon stops were the issue). We're ready to move on.