J. Kissel, for the everyone

Since we're running out of Tuesdays before O1 / ER8 to do "invasive" activities that have been traditionally lumped into the term "maintenance," we'll be performing a several of these activities tomorrow morning (Thursday 7.23). The idea is that Tuesdays are typically swamped/confused by CDS Software maintenance, and much IFO hardware and electronics tuning needs CDS up-and-running. We intend to start these activities after the operator training period ends (at 09:00) and complete all activities by 12:00 PT, and recover the IFO with great vigor, ASAP, as though it were a Tuesday.

There are several activities in the list below which are still "maybes" because the associated electronics were not known to be ready at the time of this aLOG, but those task leaders in question were working hard on having the electronics ready today, and we'll reassess in the morning.

 (All times Local/Pacific)
09:00 ETMY HEPI Pump Accumulator repair 1 hour (H. Radkins)
          To fix problem found on Tuesday (see LHO aLOG 19796) 
      PSL PMC alignment adjustment 2 hours (J. Oberling, P. King, PSL OPS)
          To address that the reflected power has drifted above 10% over 
          the past few months 
      Cosmic Ray Detector Commissioning 1 hour (R. McCarthy, V. Roma, J. Palamos)   
          To finish cabling up and testing functionality of CRD installed 
          on Tuesday (see LHO aLOG 19804)
      BSC-ISI Front-end Model Restarts 1 hour (H. Radkins, J. Warner, J. Kissel)
          To install SUS payload watchdog fix (LHO aLOG 19842)

10:00 Add new EPICs channels to CAL-CS model 30 min (J. Kissel)
          To support storage of reference calibration filter values at 
          calibration line frequencies for tracking slow time dependence
          of interferometer response. (See T1500377)
      Investigate ETMX PCAL Reflection PD clipping 2 hours (S. Karki, D. Tuyenbayev, R. Savage, T. Sadecki)
          To solve problems seen in variability of ETMX PCAL calibration. (see LHO aLOG 19025)
      Add GPS serial port to Corner-Station Beckhoff PLC 30 min (D. Sigg)
          To add more diagnostic signals for the recently-installed 
          external GPS clock reference (see LHO aLOG 19782)

11:00 MAYBE PSL FSS Electronics Upgrade 1 hour (J. Oberling, P. King, PSL OPS)
          To increase the frequency of the high-pass on the fast/phase EOM actuator, 
          such that an IMC lock-loss is less inclined to saturate the fast/phase EOM
          actuator and *keep* the FSS railed in oscillation, i.e. to solve problems 
          seen after FSS tune-up and catastrophe on July 14 (LHO aLOG 19623
      MAYBE Cable up and commission EX LVLN ESD Driver (R. McCarthy, E. Hall, J. Kissel)
          To finish cabling up and testing functionality of driver that
          was installed on Tuesday LHO aLOG 19803

We have been sending the PRCL length to PRM M3 and M2.  Even with the modified driver we are using for M2, there is no frequency where we can get more actuation with M2 than either M1 or M3 has.  There have been a few problems related to this not great offlaoding.  Locklosses due to using up the M2 range, glitches when the drives were near 2^16 (alog 18983 ) and locklosses where a 20 second oscillation used up the M3 drive (alog 19464 ).  

We are now sending PRCL to both M3 and M1.  A screen shot of the measured crossover (currently around 0.5 Hz) is attached.  We are roughly compensating the suspension resonances at 1.4 and 2.8 Hz, just to prevent mulitple crossovers.  We are curently using a pole at 0.01 Hz, a susComp filter that compensates for the suspension resonances, 27 and 60Hz notches and an elliptic lowpass at 70 Hz.  It is probably possible to push the crossover up above the suspension resonances, as my original suspension compensation was designed to do, this didn't work, it might be that I accidentally used an undamped suspension model to design it.  

This is implemented in the ISC_DRMI guardian now, and is fine.  It works for PRX, but the gaurdian has not been updated yet so the old offloading will come on until that is done.  We can do the same for SRM soon.  

Fil, Evan

We screwed the 9 MHz OCXO source and the 9 MHz harmonic generator into ISC C4.

To do this, we had to first unscrew the IFR, remove its feet, and then screw it back in (the feet were blocking the slot for the OCXO).

We continue the charge measurements on ETMs.

This is the first charge measurements after changing the sign of bias voltage applied to ESD (See alog 19821). At July, 21 and before ESD bias voltage was: 
ETMX (H1:SUS-ETMX_L3_LOCK_INBIAS) 9.5 
ETMY (H1:SUS-ETMY_L3_LOCK_INBIAS) -9.5
Now:
H1:SUS-ETMX_L3_LOCK_INBIAS -9.5
H1:SUS-ETMY_L3_LOCK_INBIAS +9.5

Plots are in attachment. Voltage is more or less the same, and it's early enough to consider the tendencies.

- TJ, Locking Operator, Cheryl, Operator Operator

- morning:

• See Jeff's alog for activitities 8AM-10AM.
• Locking 10AM to about noon, then too much glitching from beam tub cleaning to run full IFO and use DARM.

- afternoon: investigations by commissioners/others

- activities - short term

• PRX, Shiela
• HAM6, Jim
• charge, Leo

• cabling in electronics room, Filiberto

• Beckoff, Daniel

- activities - all day

• beam tube cleaning
• Kyle, Earnest: visits to all outbuildings, including entries into VEA's

EY, entry at 1:25PM, stayed 15 minutes

EX, entry at 2:15PM, stayed 15 minutes

CS LVEA, entry at 3:15PM, stayed 30 minutes

• WP5376
• WP5377
• WP5378
• WP5379
• WP5380

Currently commissioners have the IFO.

to help with getting the glitch rates, I'm running a script every minute which performs a DIAG clear on the models which are showing this issue. These models are: IOP-SUS[EX,EY], SUS-ETM[X,Y], IOP-SEI-E[X,Y], ALS-E[X,Y], ISC-E[X,Y].

Yesterday I started a cut-down version of this script which only cleared the ALS and ISC errors, however not every SUS glitch prodcues a remote IPC receive error so this was under counting.

We have noticed that in the past 20 hours only EY has glitched. We at still seeing two different types of IOP-SUS glitches either with or without a TIM bit setting.

On Monday, numerous ODC threshold values were changed, so says SDF.  See attached snapshot of these diffs.  I've asked around, but can't find who did made these changes...  Anyone know?  Are the new settings the best values to capture or do we need to revert?

The  BSC's and HAM's have been handling payload watchdog trips differently for a while. The HAM's watch the SUS watchdog and do a running 10 second sum on IPC errors, so if the SUS model goes down for 10 seconds, the ISI will shut off. The BSC's have not been as smart. They watched the SUS watchdogs, but when they received a single IPC error, they would just trip. This is because the logic was incorrectly converting from an error rate. This wasn't an issue until recently because IPC errors were rare, but for now, the end station SUS computers are producing occasional IPC errors. Today, JeffK walked Hugh and I through importing the appropriate SEI library part to fix this. All BSC's have been modified at the top level, and all models compiled, we will wait until tomorrow to restart. We also cleaned up some redundant stuff on the top level. To wrap up, Hugh commit the changes to the SVN. Attached screens show the changes. Unfortunately, I didn't get a before shot,  but the changes are a lot cleaner. We should get many fewer end station trips after the models are restarted.

Patrick, Daniel

Accidently stopped when we logged out of the controls account. It automatically restarted when we logged back in. The settings appear to be back, so no burtrestore has been done. However this is something to check if a problem arises.

Summary

A lower-estimate of absorption in the end test masses was measured using the end-station HWS cameras.  This can be used to get a lower estimate of absorption in the test masses.  I only got 30mins of data with the interferometer locked at 3W, we should repeat this measurement for a longer lock stretch to get a better idea of the absorption in the end test masses.  The current measurement gives an absorption of 230ppb in ETMY and 130ppb in ETMX.  Becasue we only measured for a 35min lock stretch, this will be an underestimate of the true test mass absorption.  Also, the ETMY HWS measurement looks untrustworthy, so it would be worth checking the PZT off sets.

Details

The EMT HWS cameras use the green als beam to measure the curvature change of the ETMs.  We want a single reflection of the green beam off of the ETM, we cannot take this measurement when the green beam is resonant in the arm cavity.  The green beam is usually shuttered and not present in the interferometer once the interferometer has reache DC_READOUT.  To take a measurement with the HWS, once the interferometer is at DC_READOUT and the green beam is shuttered and no longer used,  we re-open the ALS shutters and mislalign the green PZTs enough that the HWS sees no return beam from the ITM, only seeing a single bounce off of the ETM.  I choose the PZT misalignment offsets as stated in alog 17860.  Pictures of the HWS camera images are attached.  Both cameras measure 22 centroids.  The X-end image does not show a nice round beam, I may have to adjust the PZT alignment offset settings for this arm.

HWS reference centroids were taken before any locking started, with green PZTs in same misaligned state as we use when taking a measurement.

The ALS X/Y PZT2 are misaligned with type 'fixed', and with misalignment offsets:

H1:ALS-X_PZT2_PIT_MISALIGN_BIAS=15500

H1:ALS-X_PZT2_YAW_MISALIGN_BIAS=8300

H1:ALS-Y_PZT2_PIT_MISALIGN_BIAS=16100

H1:ALS-Y_PZT2_YAW_MISALIGN_BIAS=12000

The change in the spherical power of ETMY was 30udopters and ETMX was 11udiopters over a 35 minute lock stretch at 25.3W input power.  For a change in spherical power of 1udiopter, 1.06mW of power is absorbed, according to Aidan's model of the test mass absorption (LLO alog 14634).  The input power was 1.7W into the IMC, assuming 0.88 IMC-Faraday throughput efficency, 45 recycling gain, 280 arm cavity gain, 50:50 splitting ratio at BS, then 25.3*0.88*45*.50*280=140.3kW stored in the arms.  Absorbed power/stored arm power = optical absorption.  (Arm cavity gain is calculated using G_arm=(t_ITM/(1-r_ITM*r_ETM)).^2, where r_ETM=sqrt(1-TETM-L) and L=120ppm=loss in the arm. )  The arm power can also be caclulated using the four ASC_TR QPDs, which agree with the calulation using IMC input power, the variation between the four QPDs puts the uncertainty of the arm power at 15%.

Attached is a dataviewer plot of the HWS spherical power output during a 30min lock at 25W.  The shutters are opened when the shutter value=0.  I have calculated an absorption value for both test masses, but the spherical power inn the ETMY is growing in the wrong direction.  Either there is a sign error in a model or script somewhere, or this HWS is not set up correctly currently.  I will investigate this.

This measurement assumes the test masses have had enough time to reach thermal equilibrum, which actually takes longer than 30 mins.  This means that the absorption measurement is an underestimate.  It would be desirable to get a measurement of a lock stretch of >1hr.  The HWS measurement itself is quite noisy.

Hannah, Stefan

We were investigating some noise in the 70-100Hz range. Following up with Gabriele's alog (19756) we decided to check the RF36 channels and their coherence with the OMC-DCPD. ASC-AS_A_RF36_I_PIT and ASC-AS_B_RF36_I_YAW do appear to have some increased coherence in this range, but they also have a broadband coherence from 100 to at least 900Hz. We're still working to find a theory to explain this.

There are also some peaks in the coherence between PSL-ISS and the OMC-DCPD. However, the AS RF36 channels do not seem to correlate with peaks in intensity noise, suggesting some other source of noise.

We will investigate the higher frequencies during the next lock.

Summery:

DRMI_1F would not lock until I paused ISC_LOCK and ISC_DRMI

The majority of the morning was spent trying to get past DRMI_1F. What eventally did it was pausing ISC_LOCK and ISC_DRMI.

Overview:

When I arrived this morning, ISC_LOCK was stuck on CARM_ON_TR with a message saying that there was no IR in arms. Sheila had an alog from last night (alog 19821) which mentions this problem and her work around. I switched to manual and reran the PREP_TR_CARM state but that did not fix the problem.

I brought ISC_LOCK to Down and went to redo the green alignment but I couldn't get ALS_YARM to get out of the Unlocked state. To fix this I had to Unmanage ALS_YARM because it would stall and immediately go to the unlocked state.

Relocked green and then tried to lock the whole IFO again.

This time it would not get passed DRMI_1F. The AS_AIR cam looked round but it would not lock. Just incase, I tried slightly tweaking the PRs and SRs but no luck.

Went through IA since I wasn't sure what else to do. All went well there, but I had to take ALS_YARM to unmanged again.

It got through DRMI but lost lock a second time on PREP_TR_CARM. Laser powere was 1.7W , not sure if that was too big a problem.

Round 3. FIND_IR took quite a bit longer than usual but it eventually made it. Got stuck on DRMI_1F, alignment didn't look so good this time, a fair amount of pitch. I touched BS and PR2 and it almost caught a few times but no luck.

I decided to bring it back to Down and get the laser power where it should be. I found home for the rotation stage and then brought it back to 2.3W.

Round 4. FIND_IR taking its time again, but made it. Stuck on DRMI_1F again. The AS_AIR cam looked better than last time and StripTool was showing good flashes, but it wouldn't lock. Ed suggested to Misalign SRM and try to lock as a PRMI. I got it to lock as a PRMI in an odd mode, and I was able to bring the traces for ASAIR RF90 and POPAIR RF18 up. When I tried to realign SRM it broke lock. Ed talked to Kiwamu and found out that since we did not pause the Guaridans this realignment kicked it too hard.

Round 5. Stuck on DRMI_1F again so we went to pause ISC_LOCK and ISC_DRMI so that I could misalign SRM and see if I could get a PRMI again. Soon as I paused these guardians, the ASAIR cam looked like it was locked... because DRMI was locked! ASAIR RF90 and POPAIR RF18 looked good as well. Odd. I unpaused the guardians and it moved right on to DC readout no problem.

Elli said to wait at DC Readout for ~15min to allow the ASC loops to work their magic (paraphrased)

NOMINAL_LOW_NOISE @ 10:22 PST

Kiwamu broke lock loading some new filters and this time, ISC_LOCK went right through DRMI_1F.

NOMINAL_LOW_NOISE @ 11:05 PST

TJ was able to troubleshoot a few nuances from the slow locking this morning in order to bring the full lock up to NOMINAL_LOW_NOISE (more details from him later).  After a Kiwamu DARM filter load broke the lock, Kissel and I took the opportunity to LOAD COEFFICIENTS on a few of the FE's that showed partial loads.  In order to minimize the risk, we only performed the load coefficient on:

L1LSCAUX (benign LOCKIN and readback channel stuff)

H1TCS (Aiden filter tuning from yesterday)

H1SUSITMX and Y (Nutsinee DAMP filter tuning the other day)

H1OAF

Attached shows a picture of all FEs with the handful of other FM changes which were only locally loaded.  (Local loading is ok, but it masks Dave's tool which reports dates of when full loads happen.)

LVEA: Laser Safe
Observation Bit: Commissioning 

06:50 Richard – To all buildings to check property
08:00 Reset TIM, IPC, and ADC errors 
08:35 Earnest – From Caltech on site for property checks
09:15 Peter & Earnest – Going into H2 PSL and IOT2R table for property checks
09:20 Goodwill on site for a pickup – Bubba to escort
09:30 Richard – Going into the Optics lab to check on property
09:45 Filiberto – Cabling work in electronics room

Found the H1ASC EXC bit flag enabled this morning on the CDS overview.  Since locking is slow, I went ahead and assumed this was left over from midnight work, I cleared them via

diag -l

tp clear 19 *

RickS, Sudarshan, Darkhan

We've adjusted PCALX, PCALY and ESD calibration line drive levels to give a signal to noise ratio of about 100 (for 8 s FFT) over the mean science mode spectra from ER7.

The following lines have been adjusted:

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).

We continue the charge measurements on ETMs.
Results for ETMX are consistent with negative trend, now the charge is from 10 to 20 [V] Effective Bias Voltage for all the quadrants.
Results for ETMY do not not show a significant trend (probably, the data are beginning to be consistent with positive trend). Charge is below the 10 [V] Effective Bias Voltage for all the quadrants.

Note:  We had positive bias on ETMX and negative bias on ETMY after discharging procedure. So it seems possible that charging is caused by the bias voltage.