Something happened to the SRM guardian.  First we had the "can't proceed suspending" problem described in alog 16880.  Evan logged into the guardian machine, killed the process, and restarted it. 

It came back, but with some states we don't expect (like align to PD4?).  Also, there seems to be something wrong with the drop down list of requestable states, for example, "tripped" is an option in that menu.  In the attached screen shot you can see that the drop down menu doesn't correspond to the actual requested state.  I've closed and opened the medm screen several times with the same result. 

Sheila, Evan, Alexa, Stefan

The LSC MICH loop was a little marginal with phase, so we replaced its roll-off filter in FM5:
  Old:
    zpk([2.73333+i*81.9544;2.73333-i*81.9544;10+i*299.833;10-i*299.833],[16+i*27.7128;16-i*27.7128;4.0625+i*64.8729;4.0625-i*64.8729],1,"n")
  New:
    butter("LowPass",2,80)
We successfully reacquired twice with this filter, so we left it as a drop-in replacement for FM5. The old one is in FM1 for now.

The plot shows old and new filter.

Alexa, Sheila, Evan, Chris, Stefan

We implemented Peter's DARM 'SUScomp' from alog  16728. Since we can't lock with that filter directly (see alog 16840), deleted the old 'LLO' filter, but instead loaded a difference filter called 'acqLP' that makes the 'SUScomp' look like the old 'LLO' filter:
  zpk([80;500-800i;500+800i],[50;70;200],1,"n")

Guardian was updated to turn off acqLP' in FM8 instead of turning on a lead.



A note on the previous filter is also found in alog 16381.

To prepare for power increase durring full lock, we have made a few changes:

• THE IMC ugf is moved from 30 kHz to 50kHz, this increases the gain margin as shown in the attached plots.
• THE IMC guardian now calculates the gain that it should use to keep the ugf the same to within 1 dB, in the locked state.  
• We changed the minimum power angle for the rotation stage to -25 from -24.  This makes the power you get a bit more similar to the power you request.  

Scott L. Ed P. Chris S.

Today we were able to clean 50 meters of tube moving towards X-1-5 double doors. The afternoon was spent traveling to town to fill the diesel tank and fueling the support vehicles.
Continuous monitoring of beam tube pressures by the control room operator.  

07:00 - 08:00 Cris M. in LVEA
~ 8:00 Reverse Osmosis in alarm, notified John W.
08:10 Hugh transitioning BS ISI stage 2 to isolated, running measurements
08:54 Ed to H2 building
09:06 - 9:11 Sudarshan at end Y blocking PCAL beam
09:22 Elli to LVEA to align ITMX and ITMY spool cameras
09:56 Elli back
11:08 Jodi to mid station
12:30 Jodi back
13:33 Ed and Peter to H2 PSL enclosure to work on Livingston PMC
15:58 Ed and Peter done

SudarshanK and RickS

Since first noticed during the LLO Yarm commissioning effort two weeks ago, we have been chasing a subtle problem that is confusing the Pcal calibrations.

Today, we finally found the source of the problem, and fortunately it has a relatively simple remedy.

The Pcal transmitter modules use uncoated, 3 deg., BK7 glass wedges to generate the sample beams for the Optical Follower Servo (OFS) and Transmitter (Tx) Monitor photodetectors

The wedge is operated near Brewster's angle to reflect only about 0.1% for the OFS PD (first surface) and 0.5% for the Tx PD (second surface).  We have been observing slow (few to tens or even hundreds of seconds) transients in the OFS and Tx PD signals that have apparently resulted from fast, large-amplitude changes in the OFS signals, e.g. from changes in the loop gain or offset.

We have been making measurements to eliminate potential offenders and today we tracked the source of the slow variations we have been seeing to small, time-varying depolarization of the Pcal beams caused by the acousto-optic modulator (AOM) that generates the Pcal beams that are directed to the ETMs.  This depolarized light, while only a few tenths of a percent of the incident light, is in S-pol when incident on the wedge beamsplitter, so about 10% of it is reflected to the photodetectors.  By installing a polarizing beamsplitter cube downstream of the AOM the slow transients in the Pcal beams were eliminated (or at least significantly reduced - we will investigate further).

The attachment below shows StripTool trends of the H1 Y-end Pcal OFS, Tx, Rx (receiver), and AOM drive monitor signals when the AOM drive level was changed (left half of figure, up to 450 seconds), when the loop switch was closed but the loop had not locked (490-910 dseconds), then when the loop locked after the offset was adjusted (910 seconds).  Note that the OFS PD signal (blue trace) goes flat when the loop closes, but the drifts in the OFS PD signal due to the AOM-generated S-pol light is imposed on the other "out of loop" signals.

The second attachment is an oscilloscope screen photo taken after installing a polarizing beamsplitter (PBS) cube downstream of the AOM.  The green trace is from a temporary photodetector that was installed in the beam reflected from the PBS (s-pol light), yellow is the OFS PD, the blue trace is the Tx PD, and the magenta trace is the monitor of the drive to the AOM modulation input (modulates the amplitude of the 80 MHz RF).  Note that the s-pol light exhibits the long (10s of seconds) transient observed at LLO and at LHO.

The third attachment is a photo of the lab setup with the PBS and temporary photodetectors installed.

We have packaged two complete PBS hardware setups along with beam dumps for the reflected beams.  They will go out to LLO to Shivaraj's attention via overnight delivery tomorrow for installation ASAP at LLO.  We plan to install an identical setup at LHO Yend later today or tomorrow morning.  If we find that this is a suitable remedy, we will procure more hardware for LHO Xarm and the 3rd. interferometer.

One of the working standards is currently at LLO.  The Pcal calibrations will have to be repeated.  This should take about two hours at each end station.  We plan to repeat the LHO Yend calibration tomorrow.

Guardian state indices have now been added to all of the requestable, and some of the "static" non-requestable, states in the seismic guardians.

The SEI guardian state index mapping can be found in LLO Log 15748.

The indices have been added to the code, and the code has been committed to the USERAPPS SVN, but the SEI nodes have not been restarted/reloaded yet, to pull the change.  This will happen during maintenance period tomorrow.

J. Kissel, A. Staley, S. Dwyer

While investigating the MICH OLTF on resonance, I noticed that the bounce mode notch in the oplev damping loop (ellip("BandStop",4,1.5,40,19.3,19.9)) was not the same as the M2_LOCKING_L notch FM10 (ellip("BandStop",4,1.5,40,17.7,17.9)). However, the roll modes were idenitcal (ellip("BandStop",4,3,40,25.7,26.4)). Using the oplev, I measured the bounce mode to be at 19.636 Hz and the roll mode to be at 26.211 Hz. So, I added another Bounce Roll M2 lock filter FM8 that matches the filter in the oplev damping. Using FM8 instead of FM10, seemed to have improved the MICH OLTF. However, later when we lost locked and tried re-acquiring DRMI the bounce mode rung up and we immediatly lost lock. I have reverted back to the original FM10, and we can now lock DRMI again. Unclear ...

Summary--Changing Guardian code to not switch the GS13 Gains during the Isolation removes the RZ twist seen previously.

See attached, At T=1 the guardian zeros the CPS offset and Channel6, the GS13 SWSTAT switches the GS13s to low gain w/o whitening.  This is a coding error we are fixing, it should be going to high gain w/o whitening.  On channel9 at T=1 the DAMP path glitches which is seen on the RZ_INMON. After the Z loop closes, which glitches, the RZ comes on shortly thereafter and the big excursion on RZ_OUT16 swings the table.  Fortunately, the WFS loops now keeps the DRMI riding through the switch.  At T=2, the Isolation is taken down, evidenced by the OUT16s going quiet and the INMONs going noisy.  Immediately I switch the GS13 to whitened low gain and again this glitches the damping out and the ISO INMONs.  At T=3, Guardian does the isolation this time with switching the GS13s and no glitches are seen on the ISO INMONs nor OUT16s, everyone is happy.  I don't know from what the VHF spikes seen on the GS13INF (Channel7, lower right) originate but they do correlate to a transition to reduced inertial sensor noise... maybe it is the complettion of the Isolation and the BOOST filters.  At T=4, the guardian test is repeated with similar results.

The ITMX and ITMY gige cameras have been repositioned so that the IR beam is centered on the camera and so that the image is focused in IR.  The lens apperature is fully open for both cameras.  The lens is zoomed the out as far as possible while still being able to focus on the IR beam.  Note that the camera mounts are very sensitive to being touched; if the camera, camera housing or camera cable is touched even gently, the location of the spot position on the camera will change.

Laser:
Output power ~ 32 W (should be ~ 30 W)
Watchdog is active
No warnings other than 'VB program online'

PMC:
Locked for ~ 5 days, 22 hours
Reflected power is ~ 8.7% of transmitted power (should be 7% or less)

FSS:
Locked for ~ 11 hours
Trans PD threshold is .4 V (should be .9 V?)

ISS:
Diffracted power is ~ 7.6% (should be 7%)
Last saturation event was ~ 13 hours ago

SEI:
Hugh running measurements on beam splitter ISI for ~ 1 hour

3IFO:
Jodi and Gary may be in mid stations this afternoon

CDS:
tomorrow: Vacuum cabling and ESD investigations

Here is what I did tonight:

- I found an input matrix for sensing PRC2 (PR2) in full lock, by requiring that it doesn't see CHARD:
    0.5*(REFL 9I A + REFL 9I B) + 0.83*(REFL 45I A + REFL 45I B) --> PRC2_P (PR2)
  This was the crucial missing piece that was hurting us for CHARD engagement. Now PR2 is servoed faster than CHARD using this CHARD-independent error signal.
  The REFL I input matrix is therefore
        #REFL 9I A - REFL 9I B ->  INP1 (IM4)
        ezca['ASC-INMATRIX_P_1_9'] = 1
        ezca['ASC-INMATRIX_P_1_13'] = -1
        ezca['ASC-INMATRIX_Y_1_9'] = 1
        ezca['ASC-INMATRIX_Y_1_13'] = -1
        # 0.5*(REFL 9I A + REFL 9I B) + 0.83*(REFL 45I A + REFL 45I B) --> PRC2_P (PR2)
        ezca['ASC-INMATRIX_P_4_9'] = 0.5
        ezca['ASC-INMATRIX_P_4_13'] = 0.5
        ezca['ASC-INMATRIX_P_4_11'] = 0.83
        ezca['ASC-INMATRIX_P_4_15'] = 0.83
        ezca['ASC-INMATRIX_Y_4_9'] = 0.5
        ezca['ASC-INMATRIX_Y_4_13'] = 0.5
        ezca['ASC-INMATRIX_Y_4_11'] = 0.83
        ezca['ASC-INMATRIX_Y_4_15'] = 0.83
        #REFL 9I A +REFL 9I B -> CHARD
        ezca['ASC-INMATRIX_P_10_9'] = 1
        ezca['ASC-INMATRIX_P_10_13'] = 1
        ezca['ASC-INMATRIX_Y_10_9'] = 1
        ezca['ASC-INMATRIX_Y_10_13'] = 1
- Also set the PRC2 input matrix back to (1,0,0,0) in the DRMI ASC setup to make sure the DRMI angular control guardian still works.
- Noticed that the PR pointing loop output matrix denationalization for yesterday was not in the guardian. (These were found in DRMI configuration, by requiring that none of the WFS loops need to do any work for pointing changes). Added the following to the DRMI guardian ASC setup:
        # PRC1 -> PRM
        ezca['ASC-OUTMATRIX_P_1_3'] = 1
        ezca['ASC-OUTMATRIX_P_2_3'] = -0.160 # to remove coupling to PR2
        ezca['ASC-OUTMATRIX_P_9_3'] = -0.456 # to remove coupling to SRM
        ezca['ASC-OUTMATRIX_P_10_3'] = 0.060 # to remove coupling to SR2
        ezca['ASC-OUTMATRIX_P_15_3'] = 0.044 # to remove coupling to IM4
        ezca['ASC-OUTMATRIX_Y_1_3'] = 1
        ezca['ASC-OUTMATRIX_Y_2_3'] =  0.170 # to remove coupling to PR2
        ezca['ASC-OUTMATRIX_Y_9_3'] =  0.284 # to remove coupling to SRM
        ezca['ASC-OUTMATRIX_Y_10_3'] = 0.040 # to remove coupling to SR2
        ezca['ASC-OUTMATRIX_Y_15_3'] = 0.008 # to remove coupling to IM4

 - With this setting I was able to engage the following WFS:
  - MICH was never turned off
  - DHARD was already on
  - INP1
  - PRC2
  - CHARD
  - PRC1
  - SRC2
  - SRC1
- The order above is what I expect to work best for engaging. 
- However, the PRC2 loop works so well, and has high enough gain, that directly engaging all 12 loops (6 pit and 6 yaw) at the same time seems to work.
- I tested that twice - with a rather bad initial alignment.

- I left the IFO locked in the engage ASC state - I want to see how much it drifts over night.

When I came in today the ALS kept killing the MC, presumably to a bad alignment. So I tried to take the IFO through an initial alignment using the ISC_DOF guardian.
 - I had trouble with YARM_ALIGN_IR - The REFL_WFS_CENTERING didn't work, but the guardian didn't notice and pulled the ITMY into nirvana.
 - Also, SRM align didn't lock properly.
I manually aligned the stuff that didn't work, and got the back to full lock.

model restarts logged for Sat 07/Mar/2015
2015_03_07 00:26 h1fw1

one unexpected restart.

Sudarshan, Rick

We saw some transient in Pcal laser power in our recent observation. The power variation in these transients are about 20% at its max. We are working on to find where the issue is. Until then, donot trust Pcal calibartion to more than 50% (over-estimation) of what it reports.