Patrick, Gerardo

Ran the degas command through Beckhoff for both PT191 and PT192.

Started PT191 at 18:15 UTC. Turned off at 18:20 UTC.
Started PT192 at 18:23 UTC. Turned off at 18:28:35 UTC.

The trends appear to confirm the statement in the manual that the process runs for three minutes and then automatically turns off.

Jenne, Hang

Since the microseismic was high these days, we quickly checked that if the CPS FF to reduce the MICH motion was still working. The conclusion was NO...

While it worked 3 yrs ago (LHO:24134), currently it only injected a large amount of noise to the system. In the attached spectra, the blue traces were without the CPS FF, and the red ones were with the CPSFF on.

Following on from yesterday ... 

    This morning the measured front panel voltage for the mixer monitor signal was consistent with that displayed
by the MEDM screen.  Whereas yesterday it was not.

    Deferring this for now to a Tuesday maintenance period.



  Richard / Peter

Sheila, Haocun, Daniel, Terry, Nutsinee 

~5dB squeezing, ~8.5 dB anti-squeezing, NLG ~7

Green power was drifting slowly when we were taking the measurement so could be better. OPO locking crapped out just after we took the data so we didn't have more tonight. Haocun is working on the loss estimate. More recovery alog to follow. 

We had a problem with the ISS tonight, which was probably caused by the second loop.  We haven't taken the time to look into it but have disabled the second loop by turning off the input H1:PSL-ISS_SECONDLOOP_ENABLE, which made first loop stop railing.  Attached is a screenshot. 

Thomas, Georgia, Dan Brown, Craig, Sheila, Jenne

We have been able to lock PRMI and DRMI without the arms, and PRMI with the arms, so weve made a comparison of some parameters between the configurations.  Edit: In the first version of this table, I was not consistent in using the normalized and unnormalized values of POP18.  The trigger is based on the un-normalized channel, so I will use these values here.  We have been using 1.9W of input power for acquisition.  Also note that the gains I have written here are the gains used once we have locked, some of the acquisition gains are different. 

The main thing to note is that the optical gain of MICH increased by a factor of 2.8 between PRMI and DRMI without the arms, and was similar to DRMI without arms in the PRMI with arms configuration.  Based on this we guessed that the MICH gain might be too high with our normal settings (which used to work), and have reduced the MICH acquire gain for DRMI with arms from 3 to 1, which has given us several locks of a few seconds. for PRCL, there is not much of a change in optical gain between DRMI and PRMI and for PRMI with and without the arms.  It is also interesting that we are able to acquire with rather different triggering configurations in terms of the percentage of the locked POP 18 build up.  

In PRMI with the arms we are currently not able to get a build up of more than 60 in POP 18 counts, which before the vent Hang found that we had about 70 counts.  All of this can be compared to the information in 44348, when DRMI acquisition was working better. 

With PRMI locked and the arms held off resonance by ALS, Georgia centered the beams on POPAIRB, REFLAIR A and REFLAIR B.  (this POPAIR B had been done since the ISCT1 move but not the refl air diodes).  The other main change since the vent is the TCS preloading 45341 and 45523.  THe other thing to note is that today we have no wind and microseism around 0.4 um/ second, which is a little high for Hanford but we have been able to lock in these conditions in the past. 

We have been able to lock DRMI several times, although it seems to be very sensitive to alignment.  We were able to transition to 3F, but lost lock when transitioning the BS ASC from 45 to 36 twice in a row.  

The next time DRMI locked we skipped OFFLOAD_DRMI_ASC.  The shutter guardian said that it failed it's test, so we ran the test manually and it passed. 

Craig changed the ANALOG_CARM state to compensate for the factor of 2 less gain after the second photo diode was added by adding 6dB of gain in the summing junction. 

We arrived on resonance with a recycling gain of 41 without any ASC other than DHARD, and manually engaged AS36 to BS loops.  We stepped through the ENGAGE_REFL_POP_WFS step which was fine until we tried to engage PRC1 (POP QPD to PRM loop) which unlocked the interferometer. 

In our runup to O3, we have been using the ESD on ETMX for both acquisition and low noise operation.  When we do the transition from acquisition to lownoise, we move all actuation away from ETMX.  In O1 and O2, this meant that we just moved all the actuation (L1, L2, L3) to ETMY, which was already setup for lownoise.  Now, we move L1 and L2 to ETMY, but the L3 actuation over to ITMX.  ETMX's ESD driver gets some analog switching, then we move the L3 actuation back to ETMX.  However, we have been leaving the L1 and L2 actuation on ETMY. 

Part of the reasoning for leaving the L1 and L2 actuation on ETMY was that we had hoped we'd be able to fix and use the ETMY ESD, and just go entirely back to the O2 sequence with all lownoise DARM actuation on ETMY.  This would save some calibration measurements from needing to be redone.  However, we will be using ETMX's ESD for O3, so it seems sensible to have all of the DARM actuation on ETMX. 

To this end, I have looked at the differences in actuation on the L1 and L2 stages between acquisition and lownoise, and determined that we already have all of the necessary filters installed on ETMX, just in a different order than they are installed on ETMY.  I have set up a choice flag in the LOWNOISE_ESD_ETMX state where we can choose whether to move the L1 and L2 actuation back to ETMX, or leave it on ETMY.  If the flag is set to False (which it is currently), then everything will stay as it has been.  If the flag is changed to True, then ETMX's L1 and L2 LOCK_L filter banks will be set up to look like the ETMY banks, and then all DARM actuation will be put back to ETMX at the end of the state (not leaving some on ETMY).  The ALS_DIFF state resets the ETMX L1 and L2 stages for acquisition.

Since I have not yet tested this, the choice flag is left False for now, so that no settings will actually change. Once we're able to relock, we'll try a transition with the final actuation only being ETMX.

The attachment shows the difference in filters for acquisition vs. low noise for the L1 stages.  The L2 stage difference is just engaging an inverse pendulum filter.

At 01:02 utc NEG3 was valved in to the main vacuum volume.

Sheila Thomas Dan Brown Georgia Hang Keita Jenne

Here's a summary of some of the work done yesterday.  

• Turned on both end station lasers, Fil and Richard had to help us with the laser controller power at EY. 
• Some difficulties with locking the FSS  45541 and IMC relocking after the lens swap 45545
• Started initial alignment using baffle PDs, both arms were pretty far off and we had to find the TMS pointings by hand for both arms. 
• After both arms were aligned using green WFS and the camera servos.
• I went to ISCT1 while Thomas and Hang tried to align PR3 to the pre-vent alignment using first the optical lever (no X vs PSL beatnote) and the top mass osems (still no beatnote).  Finally I looked on the table and they moved PR3 -2 urad in yaw until the beams started to overlap, then I made a small adjustment to the beam splitter where the X arm beam overlaps with the PSL beam to get the beatnote strength to -2dBm.  This table was moved and replaced during the vent, so we may want to undo the 2 urad PR3 move and do all the realignment on the table.  The beam wasn't realinged onto the trans diodes or the cameras, and nothing in the diff beatnote path was touched. 
• After this Thomas, Dan and Hang completed the rest of the inital alingment steps, (IM4 and PR2 aligned for red locking of X arm; aligned PRM using PRX; the beamsplitter using MICH; SR2 and SRM using SRY)  They found no IR flashes in the Y arm at the end of this, so did a TMSY and ITMY alignment using the baffle PDs, aligned ETMY to get a good green build up, set the beamsplitter for MICH, and rest the ITMY green camera offsets from P 332.7 Y 277.5 to P 329.37 to Y 275.86
• Georgia Dan and Thomas attempted to lock ALS, and had difficulties at the ALS_COMM HANDOFF_PART3 step.  The lockloss seems to happen when we disengage the 40:150Hz z:p in the MC2 length path.  This is still a problem this morning. 
• Sometime overnight the ITMY camera server stopped running, as well as a few of our other camera, they are fixed now. 
• We redid an initial alingment, and looked at the ITMY camera.  Since the image looks very similar to what we had before, we reset the green camera references to their old positions.  
• We continued to have difficulties with the COMM handoff, checked that the digital path was fine using an old template.  Jenne and Richard set up the GPIB again which was disconnected for the HAM1 door removal, and the Georgia and Jenne found that the fast option was on on the common mode board, which since there is no daughter board there means that there was no signal going through the analog path to the IMC board. 
• now ALS is locked.

The Yarm green locking was complaining about the fiber polarization being too high, even though the rejected percent was 16 with the threshold being 30 (so, 16 being less than 30, it should have been fine).  After some more clicking (opening the fiber pol PD sub-screen from the Yarm PLL screen), I found an error message "power too high".  It looks like we have 0.086 mW but the threshold of too high power was set to be 0.080 mW.  So, I upped the threshold to be 0.09 mW for now so that we can keep working on diagnosing the COMM lack-of-locking situation.

Following on from Keita's alog entry from yesterday this morning
I looked at the mixer monitor signal.  The MEDM screen screen indicates that the mixer output is typically ~0.5 V.  With a digital
multimeter I measured 1.2 mV when the MEDM screen indicated that the voltage was ~0.7 V.  An oscilloscope trace of the signal
is shown in tp3_1.png.

    CG20FG9.tif shows the measured open loop transfer function from this morning, with the marker placed at the UGF.
The transfer function does not appear as smooth as ones I can recall from before.  Phase margin looks okay.

    Whilst I was in the enclosure, I tweaked the alignment to the reference cavity a little and re-centered the beam
onto the locking photodiode.  The FSS still has some trouble locking even when the transmission voltage indicated on
the MEDM screen exceeds the resonant threshold.  I do not know why this would be, although sometimes either the runtime
model and/or guardian takes over the common gain slider and moves it at what I think is an inappropriate time - like
when there is no light flashing in the reference cavity, for example.

I believe I have found a relevant bug report and a work around for various issues using the 'Terminator' terminal emulator program, including:

1. New terminals were placed behind existing terminals.
2. Opening a new terminal on a workspace that did not already have a terminal open on it would move an already existing terminal from another workspace to the workspace that the new terminal was opened on.

The bug report is here: https://bugs.launchpad.net/terminator/+bug/1508531

The work around is mentioned in one of the comments. Edit your ~/.config/terminator/config file and add 'dbus=False' under [global_config]. For example:

[global_config]
	dbus=False
[keybindings]
[profiles]
  [[default]]
    scrollback_infinite = True
[layouts]
  [[default]]
    [[[child1]]]
      type = Terminal
      parent = window0
    [[[window0]]]
      type = Window
      parent = ""
[plugins]


This seems to have resolved the issues mentioned above for me.

The pressure at PT-124 (just past GV6 along y-arm in LVEA) is the lowest is has been in 10 years. We know of a small leak on GV6 stem flange joint on bonnet plate. I won't read too much into this though knowing many of these cold cathode gauges are originals from iLIGO and out of calibration.

Gerardo M., Kyle R.

Today we helium leak tested the new joints on IP2 between the gate valve and chevron baffle nipple, the chevron baffle nipple and ion pump and both HV feedthroughs.  IP2 was de-energized during testing and was pumped only by the leak detector via flex lines connected to the 1 1/2" pump port.  The helium baseline (background) was < 3 x 10-9 torr*L/sec throughout testing as an audible flow of helium was applied slowly around the joints being tested.  IP2 was later energized and left isolated so as to "dry out" from its recent exposure to air.

For HAM6, only the new 2.75" CFF fiber feedthrough was tested (Fabrice M.).  For this case, the leak detector was used to back the 500 l/s turbo and the helium baseline stayed < 5 x 10-10 torr*L/sec

For HAM1, all 2.75" CFF feedthroughs on the South end were tested using the leak detector to back the 500 L/s turbo.  The helium background stayed < 8 x 10-10 Torr*L/sec throughout.

Jeff K., Evan G.

ECR: E1800246
IIET: 11305, 5205
Work permit: 7850

We revised and compiled several front end models with several updates to enable compensation for time dependent interferometer parameters, and general clean-up. We list below the changes:

  1) CAL-CS top level model changes:
/opt/rtcds/userapps/release/cal/h1/models/h1calcs.mdl
     - Removed DARM_ERR_WHITENED and DARM_CTRL_WHITENED since these are no longer actually whitened and instead are double precision channels
     - Added an IPC receiver from each end station TX PD to the top-level CAL-CS model and piped it in to the CS library part
     - Added new CFTD_DELTAL channels to the frames (CFTD = compensated for time dependence) as parallel channels to the standard DELTAL channels
     - Deleted DARM hardware injections in top level CAL-CS. These were unused
     (Note removing whitened channels and DARM hardware injections saves at least five 16k channels from being saved to frames. We added only two 16k channels and four 4k channels)

  2) PCAL library changes:
/opt/rtcds/userapps/release/cal/common/models/PCAL_MASTER.mdl
     - Removed oscillator line filters because they were unused
     - Removed RX and TX_PD_VOLTS filters and replaced with EPICS and testpoints
     - Implemented computation of optical efficiencies and force coefficients as laid out in T1800046
     - Allowed for different ADC gains and different analog AA filter gains because we care about this in the h(t) calibration at the <0.1% level

  3) Since LHO alog 44319, we have:
/opt/rtcds/userapps/release/cal/common/models/CAL_CS_MASTER.mdl
/opt/rtcds/userapps/release/cal/common/models/CAL_LINE_MONITOR_MASTER.mdl
     - completed the front end computation of the detuned SRC spring frequency and Q (f_s and Q) because we changed the tracking of PUM and UIM stage from a common time dependent scalar to be separately tracked as two time dependent scalars
     - implemented parallel path calculation for on-the-fly compensation for a time-dependent cavity pole frequency
     - added excitation point in QUAD model parallel to the calibration lines so that we make excitations for sweeps at the same point as for the calibration lines that are injected. This allows for easier removal of time-dependent changes in actuation gains so that we can search for unknown systematic errors

  4) In top level PCALEX / PCALEY model:
/opt/rtcds/userapps/release/cal/h1/models/h1calex.mdl
/opt/rtcds/userapps/release/cal/h1/models/h1caley.mdl
     - added IPC senders of TX PD signals to go to the CAL-CS model

Presentation given to the calibration group (see G1801594) will be updated to reflect these changes.