edmond.merilh@LIGO.ORG - posted 11:19, Saturday 13 June 2015 (19118)
Morning Shift Summary - 1st three hours
IFO locking difficulties continue:
I re-checked initial alignment from "the ground up" just to review the state of everything else. Green looked good in both arms. PRM_ALIGN seemed to have gone well. I did improve the alignment on PR3 slightly. I then moved to MICH_DARK_LOCKED which seemed to converge nicely. It needed a little touching but at the outset always seemed to have some movement to it. I then moved on to SRC_ALIGN, which is where TJ handed off to me.
Spent some time on the phone with Sheila trying to get the SRC alignment back to quasi-nominal. I got the spot bright and as round as I could get it. Increasing the laser power to 10W made the chore easier to deal with. It did lock but the stability was never resolved.
I took a chance at moving forward to the DRMI_LOCKED state to see what would break. As I suspected by all of the swinging going on in the intial alignment, there was no glory.
I then reverted back to looking at the PRM_ALIGN and saw that the alignment wasn't to good. Working on that now. Sheila will be in this afternoon. Fun.
As TJ mentioned in a earlier post there is an excitation showing at ETMX with 5-6 Testpoints occupied with some kind of business. We don't know what this is about and we really hope it isn't a contributing factor to our locking woes.