The load on the DCS detchar box became very high again, preventing the generation of the H1 Det Char Summary Pages. See alog: 32380. I've rebooted the detchar box and sent out emails. The summary pages should begin to catch up again, though this will take a little while.
Getting to NLN tonight hasn't been a problem so far, but there seem to be a forest of features at 18khz that are upset, and I don't see any filters to handle them. Attached spectra are from the current lock stretch (blue) and the 2 hour lock from 23 hours ago. The features around 18040 hz have been the most problematic, maybe the current bandpasses are good for some of the peaks in that region, but not others? The peak at 18038.5 has been the worst, none of the filters seem to do any good. So far I've had the best luck using a gain of 1000 on Mode 27, but .....
And before I could hit post 18038.5 rang up and broke the lock.
Just got done talking to Terra and Keita. With Keita's approval (because it seems to be required to get the IFO running stably), Terra walked me through making a new bandpass filter for this mode:
cheby2("BandPass",4,40,237,240)butter("BandPass",2,237,240)notch(238.5,20,30)gain(31.6228)
This is installed as 18038p5Hz in FM5 on Mode 27 (Terra suspects this mode is also on ETMY). Turning it on created SDF diffs that I've accepted, and I hit the intent bit 20 seconds before 6:00 local.
Jim is awesome and mode seems to be holding stable.
This one was a bit confusing because we have two ETMY modes close to one another, one at 18038ish Hz and one at 18042ish, Hz as seen in Jim's spectum. This is probably the source of TJs problems last night (sorry TJ), though when I checked earlier today the peak I trended from his shift was within the BP so I didn't suspect that to be the problem. Jim scooted over the BP and PLL set frequency to be over the 18038 Hz mode. Next day I'm in, I will create a new mode so that the two can be differentiated. Note though that the 18042 Hz mode did not go unstable just now even though we weren't damping it. I'll look into the last several locks and see which seems to be the regularly problematic one. We also weren't driving quite hard enough; Jim increased the damping gain which worked much better.
For now: If Mode27 seems unresponsive, open PI DTT and check if the growing peak is at 18038 or 18042 Hz. Then check the following:
TITLE: 12/09 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Jim
SHIFT SUMMARY: A bit of an extended recovery from the EQs led to a late shift lock. Lost lock just before the shift ended due to PI modes ringing up while I was using the facilities.
LOG:
See previous logs for most of the story.
7:57 Lock loss.
I sent an email to detchar@sympa.ligo.org this time (vs. detchar@ligo.org).
After a bit of a battle with bounce/roll modes, we have made it back to NLN and Observing.
EvanG, RickS
The HWinj schedule file on h1hwinj1 was updated as well as the Inspiral directory.
The Schedule file was loaded in the Guardian. (by Travis in the control room).
The HF Pcal line at Xend was stopped at 6:41 UTC (by Travis in the control room).
Six CBC injections are schedule to go in tomorrow morning, starting at 6 AM PST and separated by 70 minutes.
We will want to restart the Pcal line at Xend when the injections are finished, around noon tomorrow (Friday).
Screenshot of PCal X line prior to being turned off.
I also had to accept the SDF diffs for turning this line off in order to go to Observing. See screenshot.
I ran through IA twice because by the time I finished the first round, the arms had drifted off enough that ALS wouldn't lock. The second time seems to have gone better as we are now past DRMI.
The earth has calmed down enough to start relocking finally. I am struggling through IA since everything was way out of whack following the EQs.
Yeah, it's been one of *those* days...
Beverly, Terra, Young-Kim
Full results from the DQ shift may be found here.
Posted are the plots for the CPS Sensor Spectra.
HAM 2 needs a second look
Reran the HAM2 HAM3 CPS Sensor Spectra. New plot is posted below. Between 20 ans 60Hz, HAM2 looks a bit better.
We have a diagnostic setup at BSC8 that we need to run for several consecutive days. This setup utilizes rotating shaft vacuum pumps that have the potential of effecting the IFO data. Prior to the start of O2, we had Robert S. monitor the IFO signal(s) while it was locked and in "Low Noise" both with the pumps on and also off, i.e. we did "on/off" tests (see alog entry 31802). Additionally, and on more than one occasion, we had ran these for several consecutive days during which the IFO experienced long lock stretches at good sensitivity. As such, we were hoping that someone could examine the pertinent IFO data during the following two time segments to look for any evidence of these pumps running. In both cases, the pumps in question were running continuously: November 24th, 0230 UTC to November 29th, 1800 UTC and December 5th, 1900 UTC to December 7th, 0035 UTC.
Attached is a zipped tar file of spectral comparisons for the two pump-on periods cited and for an intervening pump-off period. Since I don't know what the pump frequency is supposed to be, I'm not sure where to focus attention, but I'm not seeing gross differences other than higher 60-Hz harmonics in both pump-on periods (is that expected from the pumps?), along with the overall greater excitation / upconversion of violin modes and the presence of "silent" calibration lines at 22.3 and 30.1 Hz in the first pump-on period. Here are the FScanned data intervals used: pumpon-1 -- 23.5 hours of SFTs collected between Nov24th, 0230 UTC and Nov 29th, 1800 UTC pumpon-2 -- 11.5 hours between Dec 5th, 1900 UTC and Dec 7th, 0035 UTC pumpoff -- 78 hours between Nov 30, 14:00 UTC and Dec 5th, 14:00 UTC If there are particular frequencies where I should be expecting disturbances, let me know and I'll do some zooming.
Kyle informed me offline that the pumps run at 1720 RPM (28.667 Hz) with small turbos running at 90,000 RPM (1500 Hz). Attached are zooms of bands around the first four harmonics 28.667 Hz (band sizes increase linearly with harmonic number) and around 1500 Hz. I don't see anything jumping out at me in any of the low-frequency bands that indicates an artifact restricted to pump-on times. The region around 1500 Hz is harder to interpret because of different average quad violin mode excitations and associated up-conversion. Fig 1 - 28.5-28.8 Hz Fig 2 - 57.0-57.6 Hz Fig 3 - 85.5-86.4 Hz Fig 4 - 114.0-115.2 Hz Fig 5 - 1480-1520 Hz
Earthquakes continue to occur throughout the Pacific. Latest are a 5.2 off Chile, and two more 5.2 off the Solomon’s. Microseism had dropped below 1.0um/s but is now back up to over 8.0um/s. Continue to hold the IFO in DOWN until things settle down.
