As a part of the DRMI investigation, we checked the laser power of CO2X and found that the power had dropped by a factor of two or so a week ago. However it turned out that this was due to a calibration filter (FM2 of TCS-ITMX_CO2_LSRPWR_MTR) which had turned off at that time for some reason. We switched it back on and also edited safe.snap accordingly. The attached is a 100days trend of relevant channels. As shown, the input of the monitor channel stayed at a constant value approximately in the past month or so while the output suddenly changed a week ago, indicating that the calibration filter was taken out.

I found a small mistake in the HAM_gain_matching_calculation script.

The Q of the GS13 model was wrong by a factor a few, causing a slight phase delay around the frequencies that matter for the sensor correction ([0.1Hz-0.4Hz]).  The overall amplitude was thus altered.

This has been fixed and committed into the SVN:

/ligo/svncommon/SeiSVN/seismic/HAM-ISI/Common/Misc/HAM_gain_matching_calculation.m

Here's the correct values that we have so far (I though we had done HAM2 as well, but I can't find a good set of data):

We still need to do HAM2&3, plus all the BSCs. Don't forget to put the ISI in high blend mode with sensor correction OFF when you want to calculate the gain.

Using the Guardian manager, brought down the entire ETMX SEI after capturing the current held position for HEPI.  The Guardian code has been changed to restore all 8 dofs on HEPI to reduce or nearly eliminate alignment changes from lock to lock.  Before HEPI only restored the RZ and Pitch at the ETMs.

The Guardian smoothly brought the system down with no trips.  Restarted the Guardian code and then went directly to fully isolated first time.  No problems with the idea then.  I'll step this through all the platforms as commissioners allow.

Of note, none of the DOFs on the BSC-ISI are restored like this (As opposed to the HAM-ISI where all dofs are restored.)  So, I attach a plot showing the before and after of this morning's restart.  The op-levs are shown and the HEPI RZ.  Additionally, all the rotational dofs of the two ETMX ISI stagesare show to reveal at least one lock to lock alignment change on the ISI.  All the SEI channels are in nano units, Oplevs are urads I believe.  The Stage1pitch is worst at 600nrad tilt, all others are much smaller.

• SEI HAM control loop upgrade testing (Hugh, Arnaud)
• SUS HSTS damping loop work (JeffK, Rana)
• PEM microphone work (Richard)
• 3IFO SUS storage complete (JeffB)
• PAC meeting next week
• Safety meeting held in control room after meeting; John showed picture of crushed pickup truck and talked about safe driving
• Work permits
• C&B will be shut down Thurs. due to power outage

250ml of water added to chiller.

As we found that the beam was too big on the IMC refl camera (alog 16166), I inserted a focusing lens (PLCX-25.4-20.6-UV) in front of it in order to obtain a better and wider view. The belows are pictures before and after the lens insertion.

Before

After

Both pictures were taken with the nominal exposure time of 19444 usec. In the second image, the main 00 mode is seen at the lower right. I am not sure whether if the upper part of the image is explainable by spatial higher order modes. It maybe a ghost beam. Note that this ghost-ish structure was visible with a laser card.

model restarts logged for Tue 20/Jan/2015
2015_01_20 00:05 h1fw0
2015_01_20 04:07 h1fw0
2015_01_20 10:29 h1iopsusex
2015_01_20 10:30 h1iopsusex
2015_01_20 10:31 h1susetmx
2015_01_20 10:31 h1sustmsx
2015_01_20 10:32 h1susetmx
2015_01_20 10:35 h1iopsusex
2015_01_20 10:35 h1susetmx
2015_01_20 10:37 h1sustmsx
2015_01_20 10:44 h1susetmx
2015_01_20 10:51 h1iopsusey
2015_01_20 10:51 h1susetmy
2015_01_20 10:51 h1sustmsy
2015_01_20 11:31 h1hpiham2
2015_01_20 11:31 h1hpiham3
2015_01_20 11:31 h1iopseih23
2015_01_20 11:31 h1isiham2
2015_01_20 11:32 h1hpiham2
2015_01_20 11:32 h1hpiham3
2015_01_20 11:32 h1iopseih23
2015_01_20 11:32 h1isiham2
2015_01_20 11:32 h1isiham3
2015_01_20 11:58 h1fw0
2015_01_20 11:58 h1nds0
2015_01_20 12:49 h1fw1
2015_01_20 12:49 h1nds1
2015_01_20 12:57 h1broadcast0
2015_01_20 12:57 h1dc0
2015_01_20 12:57 h1fw0
2015_01_20 12:57 h1fw1
2015_01_20 12:57 h1nds0
2015_01_20 12:57 h1nds1

maintance day preceded with two unexpected restarts. Restart tests on SUS ETMs. Power cycle of h1seih23 for noise hunting. Power cycle of DAQ solaris boxes, followed by DAQ restart for new slow controls ini files. Conlog frequently changing channels report attached.

Alexa, Evan, Koji, Arnaud, Sheila, Rana

The good news is that ALS is quite stable tonight, staying locked for up to 2 hours.  

• Earlier in the day we struggled for a while to recover alingment after maintence day.  We had difficulty locking DRMI plus the arms, the DRMI ASC didn't work well, with the arms.  We eventually turned off the ALS WFS, locked DRMI without the arms, used the ASC (MICH, SRC1, SRC2, and PRC2), and offloaded.  Since then we have not had much problem with the DRMI alingment.  It seems that actuating on the ITMs with the green WFS may be spoiling our DRMI alingment.  For now the green ASC is off, with the inputs turned off, so that even when the Gaurdian thinks the WFS are on, they are not. 
• We also have turned off the IMC ASC DOF4.  
• DRMI lock acquisition has been slow tonight, sometimes taking about a half hour.  We checked our open loop gains, which were all normal.  We would like to spend some time speeding this up tomorow so we can make progress faster.  
• We noticed that we were mostly adjusting the alingment of ETMX pitch in the positive direction after the arm transmission would drop, Arnaud noticed that the top mass moved by 10 um starting at 11 am this morning, the same time as a small temperature excursion.  
• We have had two trips of ETMX tonight, which were ISI, Hepi and suspension trips (the first was at 5:15:26 UTC Jan 21st, the second at 7:30:15 UTC) Arnaud investigated the second one, and found that there was a large (200 um) impulse sent to HEPI from the tidal feedback right before the trip. The six hour trend of the signal sent to HEPI shows that the tidal system has sent some relatively large impulses to HEPI several times tonight (second screenshot). 

We have been having trouble transitioning to 3F tonight.  We can transition MICH and PRCL fine, but we have seen a lot of noise at 300 Hz when we try to transition SRCL to 3F.  When we try to transition we see noise at 23.5Hz.  

ALS lock loss times: (all Jan 21st UTC) 0:03:02, 0:34:26

ALS lock loss +HEPI, ISI and sus trips: 7:30:15, 5:15:26 

Lockloss and bad misalingment of IMC due to DOF4: 6:35

Comparison of the OMC length noise for H1OMC and L1OMC.

Note that floor noise of the L1 measurement was limited by the intensity noise at the time.

Math puzzle: What's wrong with this UGF Servo?

its installed for use in the OMC and LSC at the moment, and could be used in the ASC if we find we want to hold the UGFs constant during TCS tuning.

Rana, JeffK, Kiwamu,

We did some maintenance items on IMC ASC. The major activities are:

• We had a difficulty in restoring the IMC alignment back as we ran the offloading script when the HEPIs were down and therefore we screwed up the alignment.
  • Interestingly, restoring the suspensions using the witness sensors as references did not work at all. Simply burt-restoring the suspensions and ASCIMC frontends brought it back to a good lock-able alignment.
  • After the recovery, we ran the offloading script again and so all the MC suspensions now should be in good alignment.
• We set a limiter in each loop with a hope that this is going to reduce a risk of tripping the suspensions (alog 16138, 16128) . Here are the counts we set for the limiters:
  • DOF_1_P(Y)_LIMIT = 125
  • DOF_2_P(Y)_LIMIT = 125
  • DOF_3_P(Y)_LIMIT = 250
  • DOF_4_P(Y)_LIMIT = 3000
  • These values are derived such that they are roughly the same as their 5 sigma deviations in 100 days trend except for the DOF4 loop which had hit the new limiter once in this evening. So we set the DPF4 to a high value.
• We disabled the 2nd whitening stage in MC2_TRANS QPD because the signals were saturating most of the time when IMC was not locking.
  • Therefore the MC2_TRANS QPD now has one whitening filter.
• We cleaned up the control filters and installed a new low-pass in every DOF. Rana will report some more details about this.

Also, tomorrow or sometime this week, we might insert a lens in the REFL gigE path as the REFL beam now is a bit too big to be able to cover the spatial higher order modes.

Alexa, Evan, Dan, Sheila

We have been having intermittent problems for the last two or three days.  This evening we traced the problems we've been having with ALS COMM (alog 16129 ) to an oscillation of the PSL noise eater.  The tell tale symptom was amplitude noise at around 900 kHz on the PSL light.  We don't know of a good indicator of this problem from the control room.

We do not know if this was the cause of our mode cleaner lock losses over the last few days (alog 16128 ),  or to tripping of MC1+MC3 suspensions and HAM2 ISI.  

After I toggled the noise eater switch the ISS first loop was unable to lock.  For now we have turned it off. 

We had the outputs held on the IMC WFS DOF4 from late last night until 8 pm today. We didn't see any trips of MC1+MC3 today.  Now we have turned DOF4 back on.