Today we have spent most of the day trying to lock. We have locked, but only after some diifictulties. 

•  We saw that even with winds of only around 10-20mph, we are better off with high blends.  
• We moved the RF DARM transition earlier in the CARM offset reduction procedure, to an arm build up of about 10 times the single arm, which is what Den says they had at LLO before reducing the modulation depth. We are also engaging the DETM WFS right after transitioning to RF DARM.  
  • The hope is that these two things will make the lock acquisition sequence more robust if we start with a bad alingment.  In that case we are at a smaller CARM offset than we should nominally be at, and we can see that the ALS DIFF noise is large and the misalingments on the AS camera become large before we turn on the DETM WFS.  Hopefully this will prevent the type of lockloss we have been having in the guardian state switch to QPDs.  
• We saw that the CARM gain was not right when we are on TR carm, because of the IMC gain chage I made on monday.  (alog 17150)  Now the gain in the IMC refl servo board input two is increased from -4 to -2dB. 
• We've had some difficulty engaging DRMI ASC loops, especially PRC1, mainly because we end up with a spot on POP A that is different enough from our reference after doing the inital alingment that we saturate M3 of PRM.  Stefan working on solving this by engaging the loop with an offset which is slowly ramped down.  

Chris, Alexa

Loop Gains

The first two attachments show the OLTFs of the various length DOFs. In these plots, the model is the blue trace and the red trace is measured data. The DARM TF agrees pretty well. The PRCL and SRCL loops appear to have a gain missing. The CARM and MICH model loops are not correct. 

Noise Budget Overview (***Rough Estimates***)

The fourth attachment depicts the noise budget produced by the model for the 8W lock on March 04, 2015 15:30 UTC. This roughly agrees with the conclusions Evan has made with his NB (LHO#17101). At high frequencies we are dominated by shot noise. At around 300 Hz we suspect intensity noise (or maybe beam jitter), as Gabriele noticed. From 30-100 Hz we are limited by DAC noise. And below 10 Hz we see some angular fluctuations. 

Noise Budget Details

• Sensing Noise: The OMC dark noise was measured previously (LHO 16656) in mA/rtHz. We use the measurement with two whitening stages engaged and propagate this to darm. We find the conversion 1.56e12mA/m below the cavity pole.
• Intensity Noise: We use the second ISS loop out-of-loop PDs (currently PDs 5-8) to measure the RIN. We then measured the OMCPDSUM/ISS_PDSUM58 TF to determine the calibration from RIN to W. The third attachment shows the model (blue) optickle TF and the measured (green) TF. During this TF we only had coherence between 200-300 Hz. At this point we see that the model is -20dB relative to the measured data. This explains why the intensity noise looks too low in the NB plot. When the IFO is locked we should take this TF (/ligo/svncommon/NbSVN/aligonoisebudget/trunk/Dev/DRFPMI/Validation/H1Data/RIN2OMCDCPD.xml). Then the optickle model TF can be replaced with the actual measurement.  
• Angular Noise: The model uses live parts to measure the spectra in cts at the PUM stage of the quads. We have used an undamped model to convert these counts into displacement in P and Y of the test mass. We assume no coupling of P2Y and Y2P. Our cailibration from m to radians also needs to be checked. This produces a very rough estimate of angular noise. 
• We are using an ESD strength of 4.2e-10 [N/V^2], which is different than what Kiwamu uses for the calibration (2.8e-10 [N/V^2] LHO# 17206). The spectra agree within about 20%, which seems better than what one would expect with the differences in ESD strength.

SudarshanK, RickS

Today we had a quick look at our calibration data from Yend, taken after installing a polarizing beamsplitter downstream of the AOM (see aLOG 17145).

We will post a more detailed log after we have fully digested the data, but the preliminary result is that the new calibration of the Tx PD signal is within 6% of the previously reported number (see aLOG 16718).

This is about what we expected from our recent measurements of the signal drifts resulting from depolarization in the AOM.

Added 689 channels. Removed 123 channels.

The X direction at end X and the Y direction at the Y end are blended at 90mHz.  Sensor correction is in the normal conifugration (no BRS).  This was done at around 22:58 because we have had several lock losses due to large motions in the arms that ALS cannot handle. 

This was at about -30 minutes on this screenshot, as you can see the arm control signals are reduced with the higher blends.  

There is nothing that look like high ground motion on the seismic FOMs, although the winds are a little elevated (gusty 10-25 mph)

Corner station to X-1-5 double doors of the beam tube has been cleaned. Lights were relocated, support tubes vacuumed and moving north towards mid station from X-1-5 double doors. 
Looking into purchasing a suitable generator for this operation, the previous one not necessarily designed for this type of duty. We are still able to use site power for this section of cleaning.

Beam tube pressures continually monitored by control room operator during cleaning operations. 

Times in PST

07:00 Karen and Cris to LVEA

08:49 Richard to EY electronics bay

09:11 Peter King to Mid X

09:17 Richard back, Fil to EX electronics bay

09:30 Peter back

09:37 Fil back

09:39 Peter to Mid X

09:48 Corey to squeezer bay

10:10 Peter and Richard back from MX

10:26 Kyle to LVEA checking pumps

11:56 Corey out

13:38 Corey to squeezer bay for 20 min.

15:33 Dave/Ryan Fisher restarting OCD Master model

I'm posting some plots of the performance of the BSC-ISI's. The attached pdf has 18 plots, the first 12 show the contributions of each control path to the performance of the ISI, shown against aligo requirements, sensor noises and ground motion. The order is St1 X (p. 1), St2 X(p. 2), St1 Y(p. 3),...  for x, y, z, rx, ry, rz. The configurations measured were offline, damped ISI, St1 ISI isolated / St2 damped, isolated (both stages), isolated with tilt decoupling, isolated with tilt decoupling and sensor correction, isolated with tilt, sensor correction and feedforward from HEPI. HEPI was off for the offline measurment as well. The blend filters used were the normal blend filters (the rdr compliment of filters with the T750 blend on St1 RZ). Please note that on the rotational plots, I used "paralell" ground direction (Y for RX, X for RY, Z for RZ). No, it doesn't make perfect sense, but X can be injected to RY or vice versa, and the BSC's have a coupling from Z to RZ, that we need to be aware of.

The last 6 plots show the final performance (i.e. our current configuration with damping, isolation, tilt decoupling, sensor correction and feedforward) for each dof for both stages.

Similar plots for the HAM's are next.

The data concentrator h1dc0 died from a kernel panic just before 9:00 PDT this morning and required the reboot button to be pressed for recovery.  The startup was delayed by the need for a file system check on the boot disk (343 days since last check), so data collection didn't restart until 9:34 PDT.  Also of note, monit did not cleanly restart the daqd process.  

The mx_stream needed to be manually restarted on h1sus2b, h1susauxh34, h1susex, h1susauxex, and h1susauxey.

Evan, Alexa

This morning we found the Y-ARM IR fiber polarization to be in the wrong polarization at 45%. Evan and I adjusted this back down to 2%. It's been a while since we have to do this. 

Aidan, Nutsinee, Jim, Dave:

an apache web server was installed on h1hwsmsr to provide web access to the HWS camera image files. This is an internal web service with no offsite access running HTTP protocol. Its URL is http://h1hwsmsr

model restarts logged for Sun 08/Mar/2015
2015_03_08 00:26 h1fw1

one unexpected restart. Sunday reporting was given Saturday's date, possibly caused by time change to PDT. All times subsequent are now local PDT.

model restarts logged for Mon 09/Mar/2015

no restarts reported

model restarts logged for Tue 10/Mar/2015
2015_03_10 09:49 h1calcs
2015_03_10 09:54 h1calcs
2015_03_10 10:10 h1odcmaster
2015_03_10 11:30 h1pemex
2015_03_10 11:36 h1alsex
2015_03_10 11:36 h1calex
2015_03_10 11:37 h1calex
2015_03_10 11:38 h1iscex
2015_03_10 11:41 h1pemex
2015_03_10 11:45 h1iscex
2015_03_10 11:50 h1iopiscex
2015_03_10 11:50 h1iscex
2015_03_10 11:52 h1alsex
2015_03_10 11:52 h1pemex
2015_03_10 11:56 h1calex
2015_03_10 11:56 h1pemex
2015_03_10 11:58 h1alsex
2015_03_10 11:58 h1calex
2015_03_10 11:58 h1iscex
2015_03_10 11:59 h1iscex
2015_03_10 12:07 h1asc
2015_03_10 12:16 h1iscex
2015_03_10 12:21 h1iscex
2015_03_10 12:26 h1iscex
2015_03_10 12:47 h1omc
2015_03_10 13:41 h1omc
2015_03_10 13:46 h1lsc
2015_03_10 14:41 h1odcmaster
2015_03_10 15:01 h1alsey
2015_03_10 15:01 h1iopiscey
2015_03_10 15:01 h1pemey
2015_03_10 15:03 h1caley
2015_03_10 15:05 h1iscey
2015_03_10 15:09 h1broadcast0
2015_03_10 15:09 h1dc0
2015_03_10 15:09 h1fw0
2015_03_10 15:09 h1fw1
2015_03_10 15:09 h1nds0
2015_03_10 15:09 h1nds1
2015_03_10 15:09 h1odcmaster
2015_03_10 15:11 h1calcs
2015_03_10 15:13 h1omc
2015_03_10 16:26 h1pemex
2015_03_10 16:34 h1pemey
2015_03_10 16:36 h1broadcast0
2015_03_10 16:36 h1dc0
2015_03_10 16:36 h1fw0
2015_03_10 16:36 h1fw1
2015_03_10 16:36 h1nds0
2015_03_10 16:36 h1nds1
2015_03_10 16:56 h1pemex
2015_03_10 16:56 h1pemey
2015_03_10 17:05 h1dc0
2015_03_10 17:06 h1dc0
2015_03_10 17:07 h1broadcast0
2015_03_10 17:07 h1fw0
2015_03_10 17:07 h1fw1
2015_03_10 17:07 h1nds0
2015_03_10 17:07 h1nds1

• C1PLC1 9:47 3/10 2015
• C1PLC2 13:33 3/10 2015
• C1PLC3 9:50 3/10 2015
• X1PLC1 11:52 3/10 2015
• X1PLC2 11:52 3/10 2015
• X1PLC3 11:52 3/10 2015
• Y1PLC1 11:46 3/10 2015
• Y1PLC2 11:46 3/10 2015
• Y1PLC3 11:46 3/10 2015

no unexpected restarts. Please refer to slow controls alog for Beckhoff restarts. FE and DAQ details in CDS maintenance alog.

CDS maintenance summary, Tuesday 10th Mach 2015.

ODC work, WP5095

TJ, Ryan, Stefan, Daniel, Dave:

All three ODC models were slowed from 32kHz to 16kHz. Additional shared memory ODC IPC transmitter channels were added to the end station PEM, CAL and ALS models. Further ODC changes were made, please see the ODC team's alogs for details.

Shuffle of end station ISC models WP5095

Daniel, Jim, Dave:

The PEM and CAL models, which were sharing a single core, were split back into their own cores. The ODC model, which had its own core, was combined with the ISC model and given an RFM IPC sender. The original CAL DCU-IDs were used, and the new ones assigned to ALS were returned to the pool. The CAL core number was changed as it was conflicting with ISC

In the following table, each model's dcuid and core number is shown. Models which share the same core are color coded.

The dcuids 126 and 127 are no longer used.

The data from the PEM models were slow in recovering, I eventually remembered that the ADC part in the model should be changed from ADC1 to ADC0 and all the internal bus selectors modified accordingly.

PCAL model changes

Rick, Sudarshan, Dave:

The PCAL common model was modified to give a more logical ordering of its inputs (in order of ADC channel number, PCAL signals first, Timing signals last). h1calex and h1caley were modified accordingly.

Attempt to pre-load the PSL ODC DAQ channel type change

Daniel, Stefan, Ryan, Dave:

It was suggested that the fix of the PSL ISS ODC DAQ data type problem (it is FLOAT, should be 32bit UINT) could be preloaded and applied whenever the PSL is next restarted. Well, in hindsight this is not possible since the new INI file was taken by the DAQ on restart. I backed out this change and verified that only the ODC channel was corrupted for a few hours when this was tried.

DAQ restarts were necessary to support the above work, a few more than originally intended due to PEM and PSL changes.

Stefan, Elli

After maintenance day today there seemed to be a lot of changes to the interferometer confirguration, so we decided to try to lock the full interferometer to check this still works.  When requesting Check_IR in LSC_Lock guardian, the ALS_COMM was not finding the comm beat note.  The IR buildup in the x-arm (LSC-TR_X_A_LF_OUTPUT) was 0.7 rather than 1, and guardian would not recognise the IR resonance.  We suspected a bad alignment but we did the initial alignment twice (getting an x-arm buildup of 1  at the input_align step) and repeating the initial alignment didn't help.  In order to push on to ALS_DIFF, Stefan was lowering the LSC power scale from 3 to 2W (IMC input power stayed at 3W) so that the guardian would rocognise the comm beatnote.

Once IR comm and diff beat notes were found, we brought the LSC power scale back 3W and let DRMI lock.  DRMI would catch lock but soon after the ASC loops engaged they would break the lock.  PRC1 broke the lock twice, so Stefan turned off  the PRC1 loop, and could keep DRMI locked for a bittle longer, but then SRC2 took it down.  These are the two pointing loops.

Nutsinee, Elli

This morning we visited end-x and end-y to get the HWS working there. We can remote login to the h1hwsey and h1hwsex computers and the relevant software is installed.  Daniel connected camera and frame grabber enable switches in the Beckhoff system (alog 17176).  We confirmed cameras and frame grabbers turn on when requested by epics.  We can run serial_cmd and take.  On Thursday we will check alignment of the green beam onto the cameras.

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.

In response to Evan's alog (alog 17065), I took a look at the DARM spectra. Here are conclusions at the moment:

• In the 2.8 W configuration, the optical gain seems to have decreased by approximately 9% compared with the noise curve from Feb. 26th (alog 16982) with the assumption that the high frequency band is limited by shot noise. This resulted in a too-good noise curve last night.

• The origins of this discrepancy is not clear.
  • Note that the arm build up (e.g. ASC_TR_X(Y)_B_QPD_SUM) were lower than that of Feb. 26 th only by 1-2% which is not big enough to explain the discrepancy. See the attached trends for more details.
  • One possible factor can be different sensing gain in the digital system such as OMC-READOUT_SCALE and LSC input matrix which the midnight lockers change every time they are transitioning to DC readout. I did not get chance to carefully go through these values yet.

• In the 8 W configuration, the 9% discrepancy was inherited and hence too good noise again by 9% above 1 kHz. On the other hand the power scaling from 2.8 to 8 W seems to have been done precisely.

• A strange thing is that the noise curve at around 2.8 kHz became further too low for some reason in the 8 W configuration. This can not be explained by the 9% overall discrepancy factor. The noise in this region seems lower by 10-ish% than the GWINC curve.

(Noise spectra)

The data sets that I used are from:

• 2015-02-26 10:2:50 (at 2.8 W)
• 2015-03-04 10:08:55 (at 2.8 W)
• 2015-03-04 14:03:55 (at 8 W)

Here is a comparison of all three curves with the GWINC theoretical curves above 400 Hz up to 7600 Hz.

As Evan reported, indeed the measured curves from last night are lower than the GWINC curve in 1 - 4 kHz band while the one from Feb-26 looks fine.

(Discrepancies between the curves)

Now, I want to answer how much the Mar-4 data differed from the one from Feb-26th by taking the ratio between them. I divided the Feb-26th by Mar-4th spectra in 400-7600 Hz band. Then I convert it into a histogram to see how they differ on average. Since there were many peaks whose amplitude varied as a function to time, I excluded them by limiting the histogram range from 0 to 2. The ratio is shown as red bars in the below plot.

Note that I could have done a fancy Gaussian fit for it, but for now I picked the highest bar in the histogram in order to coarsely estimate the ratio. As shown in the plot, the Feb-26 data had a higher noise level by a factor of 1.09 on average.

Then I did the same ratio analysis for the 2.8 W and 8 W data of Mar-4th. It is shown as blue bars in the same histogram plot. Picking the highest bar, I measured the ratio to be 0.58 which agrees with what we expected i.e. sqrt( 2.8W / 8W) = 0.59. So the power scaling from 2.8 W to 8 W seems to have been done correctly last night.

(Unexplainable dip at around 2.8 kHz in the 8 W data)

However, it is not the end of the story yet. The noise curve of the Mar-4 at 8 W had a funny feature at around 2.8 kHz where the noise go down below the GWINC curve even if i apply the 9 % correction.

The below plot shows "normalized" spectra of all the three data sets. In order to line up all the spectra at the same level, I "normalized" the Mar-4th-2.8W data by multiplying a factor of 1.09. In a similar manner, I "normalized" the Mar-4th-8W data by a factor of 1.09/0.59. In this way I checked the shape of all the spectra.

The Mar-4th-8W data was lower by the rest of the two curves by 10-ish %. I did not do a serious histogram analysis.

Finally , if I apply only the 1.09 correction factor to the data from last night, they look like this:

Apparently the Mar-4-8W data is lower at around 2.8 kHz than the GWINC curve.