Title:  08/19/2016, Evening Shift 23:00 – 07:00 (16:00 – 00:00) All times in UTC (PT)
State of H1: Relocking after PSL back in operation.   
Commissioning: 
Outgoing Operator:  Ed
 
Activity Log: All Times in UTC (PT)

23:00 (16:00) Start of shift
23:12 (16:12) Filiberto – Powered on ITM HV power supply
00:11 (17:11) Kyle – Into LVEA to adjust RGA in Vertex
00:19 (17:19) Kyle – Out of the LVEA
04:58 (21:58) Sheila & Terra – Going to IOTC1 to work on camera alignment
05:20 (22:20) Sheila & Terra – Out of the LVEA


Title: 0819/2016, Evening Shift 23:00 – 07:00 (16:00 – 07:00) All times in UTC (PT)
Support:   Sheila, Terra, Evan
Incoming Operator: N/A

Shift Detail Summary:  Commissioning work continuing.

This week we were put h1fw0 back into an unstable configuration by asking it to write out all the frames (full, science, strend, mtrend).

We were able to extract some useful information from the crashes.  The main point is that for some reason IO starts to become unstable and the raw frames end up taking too long to write.  This eats up all the internal buffers, and the system crashes.

I did some tweaking of nfs settings which brought the frame writing threads to have more stable write times.  Even with that a hiccup was observed which allowed the science and full frame to get a cycle out of sync, with the full frame writer being unable to catch up.

Today after looking at the code I have a new build of the framewriter running on h1fw2. This splits the framewriting thread into two parts, to allow parallel execution and allow the full frame writing threads the chance to catch up if they fall behind.  So far h1fw2 is stable.  We will test it on h1fw0 next week.

4pm local

45 sec. to overfill CP3 with 1/2 turn open on LLCV bypass valve

LLCV is currently as 20% open

The ITM ESD HV power supplies were powered on this afternoon ~4:15 PM. I believe the units have been off since the HAM6 vent.

• mostly opportunistic maintenance
• LASER back on. revovery/alignment process begun

This was done using JIm W's new script! (More on that another time)

All OpLevs look good, except ITMX Pit. Seems to be slowly drifting off, current value at 13.

FAMIS#4689

Kyle, Chandra

Isolated turbo on top of HAM 6 and spun it down, turned off scroll pump, decoupled foreline piping. Left turbo energized until bearing if fully de-levitated. 

NOTE: climbed on top of HAM 6 to do this work. 

Will de-energize turbo by Monday.

P. King, J. Oberling

Short Version:  The PSL is now up and running following the HPO water leak (first reported here, repairs reported here).

Long Version:  This morning, after giving the HPO ~48 hours to completely dry, we inspected the HPO optical surfaces.  The only thing found was some water spots on the head 1 4f lens (this was drag wiped clean); all other optical surfaces look good.  We then slowly brought up each head individually to ensure no contamination was causing the optical surfaces to glow; all good here as well.  The HPO was then successfully powered up an allowed to warm up for several minutes.  The front end came on without issue and the injection locking locked immediately.  After allowing the system to warm up for ~1 hour, I attempted to lock the PSL subsystems (PMC, FSS, ISS).  The PMC did not want to lock; according to Peter this was likely due to a slight horizontal misalignment (this is seen in a trend of the QPD that lives in the ISS box.  I unfortunately don't have a copy of it).  I returned to the enclosure and tweaked the beam alignment into the PMC and it locked without issue.  I then tweaked the PMC alignment further to maximize the power throughput.  PMC now has a visibility of ~80% with ~122W transmitted (with ISS on).  The FSS and ISS both locked without issue.  The PSL is now operational and fully recovered from the water leak.

The RTD module in the Beckhoff Link chassis what replaced this morning.  This module was showing problems since installation and was low on the list for replacement.  This morning we took advantage of PSL outage to take down the end station Beckhoff chassis to swap out this module. (EL3202)
The glitching is gone.

Last week HAM6's vacuum gauges were upgraded from the original pirani-coldcathode pair to the new Beckhoff Infinicon BPG-402. The new gauge has two channels (MOD1 and MOD2) which both record the vacuum over the full range of atmospheric (760 Torr) down to 1.e-09 Torr

I have renamed the archived Cold-Cathode minute trend files to match the new MOD1 name. In other words, if you ask for minute trend data prior to 8/10 for channel H0:VAC-LX_Y0_PT110_MOD1_PRESS_TORR you will be given data for the CC channel H0:VAC-LX_Y0_PT110B_PRESS_TORR. Note the archvied Pirani data is not accessible from NDS. I will write code to obtain data directly from the raw minute trend files if this is needed.

I will make the same changes for the other gauges which have been upgraded (PT170 and PT180)

Peter, Dave:

we modified h1pslfss under WP6100 to fix two bugs:

temperature channel inputs to DINCO for OOL and Ambient were swapped in the model

DINCO DAC outputs drive chans 08-11 and not 12-15

model was restarted, no DAQ restart was required.

Kyle, Chandra

Valved in IP and valved out TP. Pressure fell from 1.1e-6 Torr to 9e-7 Torr when IP was valved in and now is slowly rising with TP valved out (currently at 1.2e-6 Torr). After IP reaches thermal equilibrium we expect pressure to fall again. After that is observed we will shut down turbo + scroll (hopefully this afternoon).

Note: verified the MPC controller was ON and programmed for 500 L/s pump prior to valving back in. Read -5700 V. Now reads -5000 V with load.

Evan G., Jeff K.

Summary:
We measured the transfer functions of the OMC DCPD anti-aliasing (AA) module paths of ch13-16 for chassis S1102788. We measure this because the filter board was modified for these channels (LHO aLOG 28010). This is similar to the measurement Kiwamu made in LHO aLOG 21123. The OMC DCPD AA channels are 13 and 14 for DCPD A and B, respectively. The OMC PI AA channels are 15 and 16. We find that the notch behaviour of channel 13 matches what Kiwamu found in LHO aLOG 21123, but the notch of channel 14 is distorted (broken?). Channels 15 and 16 do not have the same notch behaviour (as to be expected for the PI paths, matching LHO aLOG 28085). These differences--compared to the calibration model reference AA filter--are below 1% in magnitude and less than 1 degree in phase below 7 kHz. While the calibration group is unaffected by the broken channel 14, noise from 65 kHz will be aliased down into the detection band. We should consider fixing this.

Details:
The setup for the measurements is shown in the first attachment, and the reference measurement (to remove the gain of the single ended to differential box) is shown in attachment 2. Each transfer function measurement is normalized by the reference measurement transfer function.

Data is saved in /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis

Analysis script is saved as /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis/process_aachassis_data_20160818.m

Plots are shown in the third attachment. Of particular note is to compare the new measurements to the AA filter model. Channel 14 (OMC DCPD B) now has a different behaviour near the notch. The difference is below 1% in magnitude and 1 degree in phase below 7 kHz, and does not force a revision in the calibration model reference AA filter.

[Alastair, Jason, Ben, Vern, Dave]

Thanks to everyone for their help getting this work done.  The Y-arm TCS laser is now running full power, and the table is fully aligned.  The in-loop photodiode is also now working again.  Details below.

Tuesday we discovered the laser on the table (SN 20306-20419D) had previously been paired with the driver that went with the spare laser ( 20816D-20510).  The laser had been outputing 40W at the time.  When the Hanford team had swapped in the 'spare' driver they actually were putting in the one that matched up with the laser (SN 20419D-20306) and the power went down to 16W.  First thing we did on Tuesday was to add irises to the table to define the optical axis after the laser.  We added blocks to the table to define laser position We then swapped in the spare laser (20510-20816D) and aligned to the blocking, and we found the power outputs were ~14W with its mating driver, and ~40W with the driver SN20419D-20306.

Checks on as much of the electronics as we could test showed no problems (RF distribution system, controller voltages, power etc).

Wednesday we decided the fastest way to diagnose the drivers was to swap them in to the working X arm table.  Driver SN 20419D-20306 gave a power output of 58W.  Driver  20816D-20510 gave 42W.  Swapping back to the original X arm laser (SN 20706-21015D) and driver combo gave 60W so at this point we left the X-table in its previous working condition.  Conclusion was that driver SN 20816D-20510 has now given output of ~40W on three separate lasers and appears to have some issue.

Moving back to the Y-table, two issues were noticed.  Firstly there was very minor discoloration on one pin of the power cable for the laser.  Ben also said that the pin looked badly seated and did some corrective work on this (we should check with him if he thinks this needs further work).  Secondly the power meter height was adjusted to make sure the aligment to the laser gave the largest apeture possible - this could with a little misalignment oclude part of the beam.

We repeated measurement of spare laser SN20510-20816D with driver 20419D-20306 getting 49W output.  We then completed the cycle of tests by putting in laser 20306-20419D with its matching driver 20419D-20306 and getting 58.6W output.  It's not clear what fixed the problems - the power cable seems a likely candidate but behavior of the laser still doesn't seem totally consistent with this (if one half of the driver was getting no current we would expect ~25W output).  We also might want to test driver  SN 20816D-20510 to check whether the power connector (which looked okay when visibly inspected) might be a cause for its performance drop.

After the laser swaps the final laser configuration was aligned to the blocking on the table and then to the optical axis with some minor tweaking of the actuators on the first mirror on the table.  The laser was aligned through the whole table.  At the mask we aligned by maximizing transmitted power, then using the FLIR camera on remote desktop (yes this works now - thanks Dave Barker) we tweaked the alignment to make the beam symmetrical after the mask.  We then aligned to the irises at the output of the table which define the optical axis into the vacuum system.  We changed the alignment onto the power meter that gives the power output to the CP because the head was too close to a focus.  We checked the calibration of the power output to the CP and this was confirmed accurate.  Finally we aligned to the two photodiodes on the table.  Inloop was not giving an output but we swapped cables with outofloop and were able to get a signal to align to.

The problems with the in-loop photodiode were traced to being a bad ADC board which has now been swapped for the spare (thanks Ben & Jason for tracking this down).

The Y-table will have the output to the vacuum system unblocked so the system is ready to go.  The laser will be left keyed off, with the rotation stage set to minimum power.  When the system is needed it just needs keyed on at the rack in the LVEA, and then power increased at the rotation stage.

Terra, Sheila

Tonight we had trouble engaging the ASC again.

• We still have trouble turning up the gain in DHARD, and didn't get a chance to look at this tonight. We did try reverting the ETMX notches but that doesn't solve the problem. 
• We also had trouble with our MICH error point being wrong, which might have been related to TCS being off durring maintence.  Now that TCS has been on for several hours the MICH loop seems to be working OK. 
• We had to restore OMC QPD offsets that weren't in SDF before today's boots.  We are now back in DC readout. 
• Once we reached DC readout we manually tried the CARM gain redistribution that we had commented out of the ANALOG_CARM state yesterday, and we did not see glitches reappear in the MCL drive.  We left this uncommented in the guardian, so we can try this in the morning.
• Jenne reset the soft offsets for our new alignment, and we also got rid of the POP A yaw offset.

Losing optical gain in POP X

We rang up what we think is a PR3 bounce mode when engaging the ASC the same way as last night.  We found that we could avoid ringing this mode up by keeping the PRC2 gain low (digital gains of -500).  Right before the OMC damage/vent, the POP X path was reworked and the optical gain seemed suspiciously low. 

Tonight we found that the optical gain has decreased even more.  Terra changed the demod phase by dithering PR3 pit (500 counts to M3) and rotated the phase positive 65 degrees, (Q1, Q2, Q3, Q4 from 55, 53, 54, 51 to 120, 118, 119, 116 ) to maximize the signal in I (minimize the Q signal).  The 2 attached figures show Terra's before and after OLG measurements (excitation gain of 50), both with Jenne's gain of -5000, showing a 10dB increase in optical gain which is about what we expected based on the dither amplitude change. 

After optimizing the phase, we did not see the 28 Hz mode get rung up, but this seems to come and go because we also didn't see it yesterday.  We quickly tried moving L2 on the POP X path, while watching the amplitude of the PR3 dither line in the POP X signal.  We moved the lens about 4 inches closer to POP X and about 3 inches further away, and didn't find any location that had more signal for PR3 so we replaced it as we found it. 

We are going to leave the IFO locked in DC readout 2 Watts with the request set to down so that it will not try to relock. The noise is bad as expected. 

I have been taking spectra from the SR785 (WP6005) whenever I get a chance over the last week to see if there is any evidence of three mode interactions in the 60kHz to 70kHz region that we will not be sensitive to with the aliased OMC DCPD HF channels that we normally analyze.
There is a consistent peak at 62935Hz, this peak is present with no optical power in the arm cavities.
There are several other more transient peaks, one of the times several had large amplitudes is shown in the first figure.
The largest peak is at 63776Hz  The maximum amplitude seen was 5E-6  This is about the same as the 18040Hz mode when it is 2 orders of magnitude above thermal noise and 2 orders of magnitude under unlocking the cavity.
The second largest is at 70160Hz and the third largest at 62336.

There is no evidence of peaks in DARM at this time at the expected aliased frequencies 1760Hz,  3200Hz or 4624Hz and the peaks that appear in the HF channels that do not appear in the normal DCPD channels do not coincide in frequency, see the second image.

Summary:

The high freqency calibration lines injected at the end of O1 (alog 24843) were analyzed to estimate the sensing function at those frequencies and compare it to the matlab DARM model. The calibration at frequencies above few kHz shows deviation from the model. The upward trend in the residual, as shown in the plot below, looks like the effect of the bulk elastic deformation of the testmass due to the misalignment of the pcal beams. However, this is not a definitive conclusion because the phase doesnot seems to suffer so much and also the error bars are too large to make a definitive statement. A set of measurement might be necessary to see if this effect is in fact reproducible.

Details:

The SLM tool was used to estimate the line amplitude with FFT duration listed below for each individual lines. The mean of the several data points was taken as the central value and the coherence of the measurement was estimated using magnitude squared coherence:

Coh = (A.B*)² / A² * B²

where A  and B are amplitude of DARM_ERR and PCAL_PD channels readout.

Freq    Amplitude    Start Time           Stop Time        Duration     FFT       Data points   Optical Gain
(Hz)           (ct)        (mm-dd UTC)     (mm-dd UTC)    (hh:mm)    (mins)      (#'s)             (kappa_C)
------------------------------------------------------------------------------------------------------------------------------------------
1001.3       35k         01-09 22:45     01-10 00:05         01:20         10           8                   0.995 

1501.3       35k         01-09 21:12     01-09 22:42         01:30         10           9                   0.995

2001.3       35k         01-09 18:38     01-09 21:03        02:25          10          13                  1.00

2501.3       40k         01-09 12:13     01-09 18:31        06:18          30          12                  0.995
 
3001.3       35k         01-10 00:09     01-10 04:38        04:29          30           8                   0.99-0.96 (Fluctuating)

3501.3       35k         01-10 04:41     01-10 12:07        05:26          30          10                  0.99               

4001.3       40k         01-09 04:11     01-09 12:04        07:55          60           5                   1.00

4501.3       40k         01-10 17:38     01-11 06:02        12:24          60          11                   0.99

5001.3       40k         01-11 06:18     01-11 15:00        ~9:00          60           9                    -----

These additional data points were added to one of the Pcal sweep done earlier during the run. In this case I picked the data from 2015-10-28. The optical gain during this sweep measurement was around 0.985 compared to 0.99-1.00 (from table above) during the high frequency injections. These optical gains were eye-balled from the detchar summary pages so I considered them within the margin of error and thus didnot do any correction.  A new parameter file is created to run this as a new set of measurement. The parameter file is stored at the following location:

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Scripts/DARMOLGTFs/H1DARMparams_20151028E.m 

A script used make the plot attached above and save the output as a mat file is located here:

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Scripts/DARMOLGTFs/make_sensing_HF.m 

The result of the the above script is saved at the following location and is also attached to this alog.

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Resulta/DARMOLGTFs/2015-10-28E_H1DARM_HF_sensing.mat

This is a quick summary of today's TCS joy. I ran another differential lensing test today. I went to the other side of the differential lensing (CO2X goes higher power).

The highest cavity pole was 352 Hz in this test.

• CO2 X 500 mW --> 700 mW --> 500 mW
• CO2 Y 230 mW --> 80 mW --> 230 mW

This time, I also took many measurements of the intensity and frequency noise couplings periodically throughout the test using Evan's automated measurement script (20470). I will analyze and post them later. The second attachment is trend of some relevant channels.