There is half as much jitter attenuation as we expect from the PMC.  Since broad band jitter noise from the HPO has been limiting our sensitivity (in addition to acoustic jitter peaks which are imposed after the PMC), it is worth understanding the jitter attenuation we get from the PMC and fixing it if possible. I originally wrote this alog after looking at data from September 11th, however the bullseye QPD seems to have been misaligned or somehow otherwise changed while people were in the PSL for maintenance period on August 29th.  This lead me to the seemingly impossible conclusion that the PMC was letting 33 times more jitter through than it should. 

I looked at a period of time when the mode cleaner was misaligned and unlocked on July 18th 2017, starting around 2:05:00.  

• Green trace Pitch jitter seen by the bullseye PD (which is upstream of the PMC), with an attenuation factor of 0.0144 based on the pointing attenuation expected from the PMC (T0900616.).  This jitter is dominated by noise that comes from the HPO.  I am relying on the calibration of the bullseye sensors into beam diameter units based on T1700126 (alog 34625), since the power on the bullseye drifted a little since the calibration was done there could be a 10% error in this calibration.
• Blue trace After the PMC, jitter is added to the beam by resonances of optical mounts on the PSL table, which causes the many jitter peaks seen in the IMC WFS signals (blue trace is the IMC WFS DC signals *sqrt(pi/8) to calibrate into beam diameters, I left this factor out in an earlier version of this log).
• Red trace We can make a projection based on the coherence between the bullseye and the IMC WFS of the fraction of the jitter seen by the IMC WFS that is coherent with the bullseye (HPO noise), sqrt(coh)*WFS B PIT spectrum.  This is a factor of 2 larger than the expectation based on the bullseye.  

One possible explanation would be that the coherence is explained by something other than jitter coupling through the PMC, like residual intensity noise or acoustics on the table, but neither of these seem to be the case (second attachment, bottom left).  There is no coherence of the WFS PIT with the SUM, which rules out intensity noise, and the table accelerometers have good coherence at the frequencies where the bullseye is not coherent (at resonant frequencies of optical mounts table acoustics explain the jitter, but not at the frequencies where the bullseye coherence is highest).

The third attachment shows that the spectrum of IMC WFS B (uncalibrated, taken with the IMC locked) has gotten noisier towards the end of O2. 

It would be good to realign the bullseye or replace it with the new version and check that it is well aligned and that the beam size is correct. After the in chamber work with the IMC bypass is finished, we can repeat this measurement with more power.  

It looks like our PMC does not attenuate jitter as much as it should, I think about 33 times less than it should. 

The PMC should attenuate pointing jitter by 0.0163 for yaw and 0.0144 for pitch according to T0900616.  

The first plot shows spectra and coherences from a time (only about a minutes and a half long) when there was 2 W into the IMC but MC2 was misalinged.  The IMC WFS DC are then calibrated in to beam widths.  The bullseye QPD is calibrated in to beam widths in the front end, (34625) in this plot I've added a factor for the attenuation we expect from the PMC.  The bullseye shows jitter that comes from the HPO with a smooth spectrum, which should be well below the measured noise on the IMC WFS with the attenuation from the PMC.  In the lower panel you can see that the Bullseye has rather high coherence with IMC WFS B PIT, suggesting that the jitter is not attenuated as much as it should be by the PMC. 

At 200 Hz,it looks like the PMC is only attenuating the jitter by about 0.47.  The WFS B PIT has 1.2e-6 1/rt Hz at 200 Hz, and a coherence of 0.5 with the bullseye, so the noise seen by the bullseye is at about the level of 8.5e-7.  The bullseye pit is 1.8e-6 /rt Hz at 200 Hz (without the rescaling I've done in the attached plot). 

Edit:  The coherence of the WFS B Pit with the bullseye cannot be explained by residual intensity noise in the pit signal which is coherent with the jitter noise.  I've updated the plot to include a trace that shows no coherence between WFS B sum and WFS B pit. 

Second edit:  The bullseye QPD was misalinged during the maintence window on August 29th, so this result be misleading.  

WP7220: Daniel, Sheila, Patrick, Dave:

Daniel's latest h1sqz, h1sqzwfs, h1asc and h1ascimc models were loaded by restarted these models.

H1EDCU_HPIPUMPCTRLEX.ini was modified to add four pressure monitor channels which had been rewired from the old purple-box ADC to the replacement Beckhoff ADC (channel names are slightly different allowing old and new to run side-by-side).

We discovered a duplicate channel name in PLC4 and h1sqz (H1:SQZ-SEED_PZT_OFFSET). Sheila made a naming change in the h1sqz model to resolve this. After this model was restarted the DAQ was restarted.

Due to an out-of-date safe.snap file for h1ascimc, the alignment did not recover correctly. Keita manually recovered some settings and I performed a full burt restore to 14:10 PST.

TITLE: 11/16 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
LOG:

16:45 Hugh to HAM3
17:00 Ed to CER
17:00 Chandra and two guest to MY
17:30 Terry to SQZ
17:45 Greg to LVEA to work on TCS viewports
18:15 Gerardo & TJ to optics lab to move OFI
18:15 Robert to LVEA to look at TCS viewports
18:30 Bubba to EY
18:45 Travis Betsy to biergarten, out 20:00
19:45 Kyle MX
21:30 Betsy, Travis, Arnab, Rakesh to HAM6
22:00 Keita, Ed transition LVEA to laser hazard
22:30 Dave restarts some models, including ASC, driving PSL PZT nutso, which apparently hoses alignment crew
23:30 Betsy, Keita, Travis, Ed, Jason out

many models showed a DAQ-CRC error ramp-up around 11:35PST. Trend and overview attached. I will investigate further if it re-occurs.

S Cooper, J Warner, S Dwyer, 

As part of the work we've been doing to try and understand how large earthquakes affect the interferometer, I've written MATLAB script that searches for the lock state of the interferometer as well as searching for watchdog trips in HEPI, the ISI and the suspension to try and narrow down the number of events that we need to do in depth analysis of. 

The attached images show the interferometer lock loss as a function of earthquake velocity across O1 and O2.There is 11 bins ranging from 400nm/s to 2000nm/s peak velocity, using the 0.03-0.1mHz ground BLRMS channel. To account for the different arrival times of different waves during an earthquake I added a start buffer of an hour to the data search to avoid more events going in the 'previous lock loss' bin. 

 From this we find that work done during the O1-O2 break has enabled H1 to remain locked in earthquakes up to 1.5 um/s peak velocity, whereas during O1 the interferometer locked in only two earthquakes at 400nm/s peak velocity, obviously the number of datapoints is quite small, so these numbers may change with more earthquakes.

Here are a couple of photos of the BS AR elliptical baffle before alignment and after alignment.  Hopefully this is stating the obvious, but the 2 photos that show the largest beam not well centered on the target are the 'before' pics and the more centered beam photos are the 'after' pics.

[Maddie W., Aaron V., Greg M.]

Here is a summary of the filters and command line arguments that should be used for the C02 frame generation using the DCS calibration pipeline.  This information is compiled from configurations wiki page and aLOGs linked from that wiki page.  The command line arguments should be the same as for C01 except for changes noted in the table below.  (Additionally, the frame names and channel names should be changed appropriately to C02.)

--expected-fcc=347.2
--coherence-uncertainty-threshold=0.004
--wings=(something larger than 600)
--no-fs 
--no-srcQ
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ

--expected-fcc=360.0
--coherence-uncertainty-threshold=0.004
--wings=(something larger than 600)
--no-fs
--no-srcQ
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ

--expected-fcc=360.0
--coherence-uncertainty-threshold=0.004 
--wings=(something larger than 600)
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ

[Gerardo, Koji]

The isolation measurement of the OFI was repeated today to confirm the stability of the optical isolation performance. For the confirmation, we have used the usual photodiode technique, as well as the power meter. Also we made the dry run of the in-situ isolation test setup [LHO ALOG 39357]. All the measurements showed the consistent isolation better than 40dB. We are going to install the OFI optical table to HAM5 tomorrow.

Methods

• PD measurement - Input beamed chopped at 342Hz. Used two large area Si PDs (PDA100). One is the reference, the other is the measurement. Take transfer functions between those as a measurement.
• Power meter measurement - Set a Thorlabs S140C (integrating sphere PD) at the reflection port. Measure the reflected power with direct reflection, back reflection through OFI (isolation), the transmitted beam dumped with a glass beamdump (backscatter), the input beam dumped with the beamdump (dark offset).
• In-situ measurement - Inject a 1mm (in rad) beam from the output port. Measure the input power and leakage power with the Thorlabs S140C.
• Ophir power meter (PD stick type) was not able to sense the weak leakage from the OFI.
• Thermometer: Fluke mini thermometer (missed to check the P/N: similar to Fluke 62 Mini)

Results

Keita, Jason, Ed, Betsy

After the IO group installed the MC bypass today, Keita, Jason, Ed and I embarked on the beam pointing from the PR to the ITMs.  We centered PR2 to PR3, then PR3 to ITMx-CP.  We utilized the new target that was already on PR3, but the beam is many inches in diameter and viewing was difficult (as anticipated).  Still we think we could see it well enough to have it centered to within ~1cm on the target.  We then removed this target and the iris in front of PR2 (which likely was clipping the diameter a bit), and looked down at the BS and then CPX.  Again this was difficult, but also doable to within ~1cm.  Jason and Keita were inside the BSC chamber and used a series of rulers and IR viewers to find reference of the beam placement on the optic centerline.

Attached is the snapshot of the IFO alignment slider settings as we've left it for the night.  We'll resume the BS to SR cavity optics tomorrow.  (We'll also continue on the Elliptical baffle alignments when the newly fabbed target is out of clean and bake tomorrow morning.

Note, we had to ask Chandra to turn down the purge a tad in order to quiet the beam a bit.

[Kyle, Chandra]

We opened back up GV6 this afternoon after closing it last Friday to leak hunt. Recap:  we checked the annulus systems on GV 5,6 & all in between for inner o-ring leaks (no leaks). We discovered 10" GV on CP1 was not tight and the volume capped by ISO flange was up to air, likely causing a slow leak into main volume. We did not spray GV 5,6, CP1, spool with helium.

We replaced the ISO with conflat reducing cross that can accommodate a turbo pump plus full range gauge and pump port. There seems to be a small (e-9 Torr-L/s) leak somewhere in this reducer cross but results are ambiguous and should not affect performance since it's behind the closed 10" valve.

The pressure reading on PT-124 (beam tube side of GV6) has dropped since tightening 10" GV, but value hasn't fallen below 5e-9 Torr which is where it is when isolated from leak. We may revisit this when we have access to the main YBM turbo for He leak checking. I would like to check the 10" GV gate seal and gappy flange at bottom of CP1.

TITLE: 11/14 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
LOG:

Dust alarms in optics labs in morning, likely due to AHU-3 work.

15:49 UTC Email from Bubba reporting that he is taking AHU-3 down
15:50 UTC Larry M. through gate
15:59 UTC Jeff B. to YBM and resetting dust monitor 4
16:10 UTC Bubba, Richard, Larry M., Victor C. to LVEA to look at TCS table
16:18 UTC Jeff B. back. Dust monitor 4 restarted.
16:22 UTC LN2 delivery truck through gate
16:26 UTC Hugh to HAM3 to balance ISI
16:52 UTC Cintos through gate
16:56 UTC Betsy to LVEA to talk to Hugh
17:00 UTC Betsy back
17:06 UTC Jim to LVEA to help Hugh
17:11 UTC Betsy and Keita taking camera crew to bier garten. Betsy also unlocking PR3.
17:12 UTC Ed to LVEA to prep for HAM2 work
17:18 UTC Ed and Cheryl installing alignment hardware in HAM2
17:23 UTC Travis to LVEA to investigate problems with walkie-talkies
17:39 UTC Jason to LVEA to talk to Cheryl
17:43 UTC Jason back and starting adjustment of PSL diode currents
17:52 UTC Travis back
17:55 UTC Chris to LVEA for FAMIS tasks
18:03 UTC Jeff K. to LVEA to help Cheryl and Ed transition to laser hazard
18:10 UTC Chris done
18:13 UTC Jim back
18:23 UTC Jason to HAM2
18:26 UTC Marc to mid Y to pickup and drop off parts
18:33 UTC Betsy, Keita and camera crew back
18:34 UTC Jason back and reports LVEA transitioned to laser hazard
18:42 UTC Keita to HAM2. Vern taking camera crew to HAM2.
18:52 UTC Camera crew getting a different camera
19:06 UTC Karen leaving end Y
19:18 UTC Gerardo to optics lab. LN2 delivery truck through gate. Sheila and Terry to squeezer bay. Kyle and Rakesh to LVEA to leak check CP1.
19:36 UTC AHU-3 back on
20:35 UTC Betsy to LVEA to talk to HAM2 group
20:37 UTC Terry back
HAM2 group out for lunch
20:58 UTC Betsy back and starting transfer functions of PR2 and PR3
21:25 UTC Terry back to squeezer bay. Turning squeezer laser on.
21:50 UTC Ed, Keita and Jason to HAM2
21:56 UTC Kyle to end Y
21:58 UTC Betsy to LVEA
22:29 UTC Kyle back
22:41 UTC Chandra to LVEA. Chandra and Kyle leak checking around CP1.
22:52 UTC Koji to optics lab
23:21 UTC Vern and camera crew back
23:44 UTC Marc to mid Y
23:49 UTC Toggled PSL FSS autolock to relock FSS

[Gerardo, Koji]

As reported before [LHO ALOG 39359], we confirmed the disqualification of the installed OFI in terms of the optical isolation. The OFI was pulled out and place in the optics lab. [LHO ALOG 39366].

Yesterday, the optical performance of the OFI was tested without any adjustment and then after the performance optimization. The reasonable performance was recovered. It's hard to believe that we can keep this 43dB isolation forever under environmental fluctuations.

Next steps: Today, some of the measurement will be repeated for confirmation of the stability. In addition, a dry run of the in-situ isolation measurement will be done in the optics lab to pin down the reference numbers and accuracy/precision.

Here the detailed testing procedure can be found in E1700350.

The transmission was checked with a Thorlabs power meter with an integrated sphere. The numbers were 0.972+/-0.004 and 0.971+/-0.006. But the systematics is large (+/-1%) everytime the number is measured.

Other OFI Performance to compare:
LLO OFI Performance summary [LLO ALOG 25788]
Previous LHO OFI measurement in the opt lab [LHO ALOG 39276]

What has been done:

- A noticeable thing was that the half-wave plate (HWP) was not tightly fastened in the holder. It is a notorious holder (Attached Pic) that the HWP can still jiggle in the holder even the screw is fastened with a normal torque. This was the issue the initial OFI of the LLO (actually... this unit). This time, the screw was fastened much tighter with an Allen key.

- Other alignment was basically fine. The angle of the thin film polarizer (TFP) was a bit tweaked to minimize the backscatter iso, but it seems that this is the minimum. This may mean that the isolation was optimized by sacrificing the polarization purity of the transmitted beam through the faraday rotator and half wave plate.

This morning I relieved the PR3 of the mechanical rubbing Kissel pointed out in 39384.  The Front HR Upper Right stop was grounded on the face of the optic.   I also freed up the locked down PR2.  We'll run some TFs at lunch when IO is finished with the MC bypass install, but before alignment through the PR chain.

J. Kissel

Since HAM4's construction / installation stuff for this vent is complete as of yesterday's HWS Scraper Baffle install (LHO aLOG 39266), and the debugging of SR2's M2 OSEM today (LHO aLOG 39277), I took the afternoon to start B&K hammering all of the new / old baffle equipment and HWS mirror / lens mounts. Note, I deliberately skipped the SR2 cage, since nothing has changed on it since it was originally measured in LHO aLOG 12089, and I trust that Betsy and Travis successfully re-dogged and torqued bolts when they finished the relocation a few days ago LHO aLOG 39240.

Will post pictures and results next week.

J. Kissel

I've taken new, more comprehensive B&K hammer response measurements of the H1SUSPRM and H1SUSPR3 cages, now that they have newly installed (what I'm calling) Venetian Baffles (see attached HAM2_NewBaffling_WithLabels.pdf for names of baffles) whose installation was finished last week LHO aLOG 39170.

These baffles have pretty high-Q, low-frequency drum-head / longitudinal resonances (roughly aligned with ISI / IFO Y axis).
  
    PRM Upper: 42.38 & 46.75, 91.00
    PRM Lower: 42.38 & 46.75, 75.62 

    PR3 Upper: 36.75, 75.6
    PR3 Lower: 36.75, 83.12 

My guess is that the lower frequency of the modes are the baffles bending in longitudinal in concert on the Venetian bracket, and the upper frequencies are their individual longitudinal modes. This mode-shape guess is based only on intuition, and that the lower frequency modes are seen in both upper and lower excitations.

The cage's transverse modes appear to be relatively unaffected by the new baffles. I'm little surprised it hasn't stiffened up any of the transverse modes; oh well.

These resonances have been identified by comparing against the history or cage resonance measurements for each of the SUS -- see the three pdfs: 
    2017-10-30_H1SUSPR3_CageResponse.pdf
    2017-10-30_H1SUSPRM_CageResponse.pdf
    2017-10-30_H1SUSPRMvsPR3_CageResonance_Comparison.pdf

Note, also new with these measurements -- data out to 1.1 kHz. The former data is from 
LHO aLOG 6014 -- VA ON vs OFF data for H1SUSPRM and H1SUSPR3
LHO aLOG 8654 -- Former Cage Baffles on H1SUSPR3

Photos attached (and remaining HitLocations.pdf) are for historical reference for future repetition.

S. Dwyer, J. Kissel

While inspecting HAM6 regarding the broken OMC REFL Beam Diverter Dump, we took the opportunity to check out the fast shutter.

We saw several things of concern:
    (1) The cabling that emanates from the shutter itself looks (and has been previously confirmed to be) very close to the main IFO beam path. Koji indicated in his LHO aLOG 28969 that "the clearance does not look great in the [above linked] photo but in reality the beam is clearly away from the wire."
    (2) One of these wires (the wire closer to the IFO beam) has a kink in it, but no visible burn marks, so we suspect this is from mechanical manipulation during install.
    (3) OM3's readout cables are kinked in a stressed position to make room for the fast shutter, which is a little forward (-Y, away from the beam splitter) of the position indicated in the drawing likely because of this interference.
    (4) Some small fleck of particulate on the inside of the "toaster" face, on the HR (back towards OM1) side of the shutter.

I attach picture collections of these things (admittedly the particulate pictures are not great -- we tried lots of times to get a good picture but failed).

Hopes:
   Re (1): Can we find a way to route these cables below the beam line, instead of surrounding it?
   Re (2): Same as (1)
   Re (3): Can we replace OM3's OSEM cables with a 90 deg backshell, so as to clear room for the fast shutter and relieve stress on the cable?
   Re (4): hopefully this is not from the HR surface of the fast shutter optic