Recovery from its biweekly crash. Note that it took down the end X ESD high voltage because the ethercat Pirani gauge runs on it. I burtrestored to 5:10 this morning. Filiberto is turning the high voltage back on.
Will change channel 2 at next opportunity
I rebooted h1conlog1-master and h1conlog1-replica to check that they could be without issues. The only thing I saw was an 'unable to contact caRepeater' for the Conlog process, which should be fine. Both are back up and running.
Elli, Nutsinee
CO2X laser mysteriously tripped this morning (*probably* due to PEM cable pulling). It untripped itself but the output power was never returned and the temperature kept dropping. We had to go in and restart the laser at the rack. Just wanted to point out that the laser READY status on Ops Overview screen doesn't always mean it's ready. Always keep an eye out for the laser power.
As Daniel noted we plugged in the 1PPS signal from the Trimble timing unit that was installed last week into the Master timing system in the MSR. This is on Antenna cable 1. I then moved the Master timing antenna to the weather station mast. I did not change the cabling as this was already on 1/4" Heliax coax cable and the unit has 3/4" connection which would be hard to make up the the 1/2" heliax and N connector. We then Moved the NTP server antenna to the weather station mast using antenna cable 2. We needed to adapt the N connector the TNC at the antenna head. This completed the intrusive GPS moves. Next will be to connect the Symmetricom GPS unit in the rack to another antenna. This will done during another maintenance period.
the workstation in the front right corner of the control room doesn't work well, sometimes it stops working completely, sometimes it is unresponsive for a few minutes then comes back.
Aidan. Nutsinee
Summary:
The CO2 ITMX ISS AC anti-whitening filters where previously (naively) set up with the complete inverse of the ISS whitening filters in the electronics. This included a pole at zero, or an integrator. This caused problems at LLO when turned on as residual DC in the input to that channel was steadily integrated over time. We fixed this problem at LLO by moving the pole from 0 Hz to 1 Hz. I added the same fix here. Also, these filters were missing from the ITMY channels, so I added them at LHO as well.
Details:
In Foton, I loaded H1TCSCS.TXT and, in the following four channels,
I set the first three filter modules to:
The key change being the removal of a pole at zero and the addition of a pole at 1Hz.
After saving the file, I hit "Clear History" and "Load Coefficients" on all four channels.
Additional information:
The ISS AC channels tell us the intensity noise on the CO2 lasers. We're particularly interested in the region 10-200 Hz where we may couple noise into DARM.
The master GPS clock has been switched from the internal GPS unit of the master/fanout chassis to the external Trimble unit. This simply required to connect the 1PPS ouptut of the new GPS unit to the 1PPS input of the master/fanout chassis. Plot 1 shows that this proceeded with a small 100ns transient in the OCXO error signal but otherwise went smooth without interruption of the timing distribution system.
Plot 2 shows 1 day of second plots trending the difference between the atomic clock and the internal GPS (DIFF_1), the difference between the NTP server and the internal GPS (DIFF_2) and the difference betrween the Trimble and the internal GPS (DIFF_3). The atomic clock was shifted by +1µs and the NTP server by +0.65µs to shift the histograms towards the origin. This measurement was done before the switch over still using the internal GPS as the master. The Trimble unit seems to have about twice the variance compared to the internal GPS and the NTP server. The difference between the Trimble unit and the internal GPS is about 25ns.
J. Kissel, B. Weaver Betsy and I have updated the end-station SUSAUX top-level models to include Stuart's new library block for the HV and LV ESD analog readback monitors, as per WP 5373, ECR E1400232, II 859. with the changes as described in LHO aLOG 18819, and obeying wiring diagram D1400177 , specifically p11. They been compiled against RCG 2.9.5, we'll wait for Dave to confirm that we want 2.9.5 or 2.9.6, and will install later in the morning, as per today's schedule (LHO aLOG 19770).
This models have been installed, compiled against RCG 2.9.5 (given the issues with RCG branch 2.9; see LHO aLOG 19793). All channels appear functional, but now we see that the digital monitor channels that were in the QUAD AUX model (which are white on the AUX overview) are now in the QUAD MASTER model have turned into bits (which are now green / grey and alive); see attached. @Stuart -- should we remove these white channels from the AUX overview screen? Note -- the cable for the digital monitoring doesn't yet exist, so the new digital monitor bits are at the moment meaningless.
h1susaux ex and ey model updates as per the above have been committed to svn.
As a precaution to working on the timing system ALL of the SUS and Seismic systems have been taken down using guardian. The addition of the 1pps into the timing system should not cause a problem but if it did this should keep equipment from potential issues as a result of the front ends freezing.
There we now have several burt references for alignment, a good 'ol snapshot never hurt anybody!
Evan, Stefan - Loops worked - simply lowered DHARD gain by 6dB. - Had some low frequency transients right after - not clear whether they are related to the matrix - seemed to diminish later on.
This is the spectrum at the end of today's work. We'll spend tomorrow looking at the calibration, but tentatively this spectrum was >65 Mpc after engaging the outer ISS loop (it was about 60 Mpc) beforehand.
There is also some fake 80 Mpc stretch where we were examining the settings in the online calibration. Our uncertainty about the calibration has increased as a result of this investigation.
Rana, Stefan
Using Rana's filter fitting tool (available in
/ligo/home/rana.adhikari/Templates/DTT/LSC/FF
or
/ligo/home/controls/sballmer/today/FF
we remeasured and fitted the MICH FF transfer function.
The new fitted filter (FF3 in FM4) is
sos(-0.000543835088, [ -1.93662264300273; 0.95485272408082; 0.30546714694311; -0.69453285305689;
-1.99510327713713; 0.99517904131748; -1.99243149865104; 0.99250763632503;
-1.99954772753581; 0.99957826550970; -1.99936615655289; 0.99939939939844;
-1.99965218293192; 0.99975661861859; -1.99993380253468; 1.00003473727562;
-1.99969845455122; 0.99979417820973; -1.99992371170330; 1.00002274176099;
-1.99981093117311; 0.99985759151419; -1.99995617290421; 1.00000284176776;
-1.99985737603421; 0.99996014647150; -1.99984813627844; 0.99995086001340;
-1.99992036795975; 0.99996576562300; -1.99993708678199; 0.99998253575133;
-1.99944212960262; 0.99996998756589; -1.99944272164552; 0.99997065091132;
-1.99975193818562; 0.99999930668374; -1.99975187384463; 0.99999929435542; ],"o")
Plot 1 shows the fit quality,
Plot 2 shows the achieved subtraction, with an artificial MICH drive.
Rana, Matt, Hang We did some further investigation of HAM5's coherence with DARM, as suggested by Gabriele (aLog # 19756). A list of what we did: 05:35:10 (UTC): Tapped the lower middle flange south of HAM5. 05:35:32 (UTC); Tapped the same flange harder. 05:35:54 (UTC): Tapped gull wing. The interferometer lost lock. Before the unlock, the IFO was operating at 24 W with LSC FF on. A plot of the corresponded time series was attached (TSaccHam5vsDarm.png). We could see ringing corresponding to tapping the flange in HAM5 channel, yet they did not seem to have a significant effect on DARM. The frequency of the ringing was 207Hz with a decay time of 1.6s. No 90 Hz feature seen. The gull wing tapping did not appear in the ACC_HAM5_SR1 that Gabriele noted. Summary: no clear connection between this ACC and DARM.
evan, rana
we did further slapping and shouting around HAM5/6 (from 10:25 - 10:39 UTC) and saw a few interesting things:
afterwards, we ran Hang's A2L script. It ran well, but takes awhile. We ought to run these in parallel.
Some times and events for analysis:
10:25:45 knocking on HAM5-south 10:26:01 knock on south door, upper west side 10:26:40 wiggle HAM5's curtains 10:27:40 wiggle HAM6's curtains 10:27:53 acoustic injection near HAM6 east side 10:28:12 ISCT6 acoustic noise 10:28:46 HAM5 north door 10:30:22 HAM5-HAM4 manifold 10:32:32 septum plate (north end) 10:34:39 HAM4-5 manifold whack 10:35:45 tube between bellows near HAM5 10:37:34 more of same 10:38:14 more of same
As previously noted, there is a new fast front end running at EY. I made a few (bad) screens to help access the filters and RMS outputs. There is no link from the sitemap yet, so access is via
/opt/rtcds/userapps/release/isc/h1/medm$ medm -x ISC_PI_START.adl
Thus far we have had only a few multi-hour high-power locks, but no parametric instabilities have yet been seen. (The fast output was, however, useful to confirm that the 6kHz line seen last night was not aliased from a higher frequency.)
I updated the IMC_LOCK guardian to make the ISS_ON state more reliably accessible when the IFO is locked. Much of this was just moving some code from CLOSE_ISS.main to CLOSE_ISS.run, and using cdsutils.avg to acquire data. I also created several helper functions to abstract some of the ISS switching.
The current guardian ISS enabling code has been tested a few times at high power, and it has worked without trouble. One new feature is that the IMC guardian keeps the second loop output value small, averaged over long times. This is a sort of "digital AC coupling" which may prevent problems with ISS actuator saturation over long locks.
With the ISS on, the DARM noise is significantly improved between 100 and 400Hz. It doesn't seem that more gain is necessary at this point.
Sudarshan, Jeff K.
The ESD calibration line at 538.1 Hz is moved up to 540.5 Hz, 0.2 Hz away from the Pcal Line at Yend (540.7 Hz) to estimate the ESD actuation strength. This is a temporary arrangment and the ESD line will be moved back to its original position next week after we have some locked data to analyze. The SDF table is updated accordingly.
The ESD line is switched back to its original position at 538.1 Hz. SDF table is updated accordingly.
Kyle, Gerardo 0850 - 0900 hrs. local -> In and out of Y-end Kyle, Gerardo Connected LD to exhaust of Y-mid turbo and sprayed helium on turbo fittings -> Found that this turbo has a "Leak valve" a.k.a. a solenoid vent valve which is either not connected or absent altogether on the site's other Main Turbo Pumps (MTPs) -> The turbo had been left levitated but not spinning since John W. and Gerardo's earlier investigation -> As such, this vent valve would be open -> Found that the clamp for the blank on this valve was loose -> Tightened -> With the turbo levitated but stopped, the QDP80 running but valved-out, safety valve and turbo bypass valve opened we sprayed the turbo's CFF and NW fittings with no obvious "smoking gun" -> It is likely that tightening the blank on the vent valve may have been the leak on the turbo side of the 10" gate valve For our next session we will vent the turbo volume and remove and replace the vent valve with a blank followed be a leak testing of the CFF joints on the Y-mid volume Also, set IP9 to Fixed 7000V -> This leaves only the X-mid still in Step Mode (currently 5000V)
Upon noticing the vent valve mounted on the Y-mid turbo, Gerardo and I examined the X-mid turbo and found that it's vent valve was not installed. Knowing that we would never use it and not ever noticing it on any of the other MTPs, I assumed that the Y-mid having one installed must be the exception. Since then, I have surveyed the MTPs at the Corner Station and found that they too have them installed, albeit blanked off like the MTP at the Y-mid. Thus, the X-mid MTP is the exception not the Y-mid MTP