[Matt, Kiwamu]

We found that the end laser had become off in this past Saturday likely due to the power outage. The interlock seemed to have been initialized --- no power was supplied to the end laser. So we pressed the small red reset button for this power line at the floor in the Y end station and this recovered the end laser back on. We didn't change any current or temperature settings.

Given the strange status of some of the front ends, we decided to cleanly power cycle all front end computers, IO Chassis, Timing fanouts and IRIG-B units (with the execption of the MSR timing master and IRIG-B which are on UPS).

This was done in the corner station CER, LVEA, EY and MX.

All front ends are now running.

The DAQ was restarted several times. All the EPICS gateways were restarted.

It as noted that VE signals from IOCS MR, LX and LY were unavailable from the power outage to today. We are investigating why.

Daniel provided new INI files for ECAT C1, I have added them to the DAQ and renamed the INI files to the EDCU standard.

Here is the current status of the aLIGO SEI work regarding the HAM chambers. Everything in bold is to be completed for HIFO-Y. Everything in red is a change from last week's status. Everything in green is available.

The site had several brief power glitches over the weekend, we are currently recovering CDS, GC. Greg reports LDAS is up and running. Greg in looking into DMT status.

[Chris and Kiwamu]

 The ALS CARM loop was engaged for the first time by feeding the ALS common beatnote signal back to the MC length. It is very stable and the longest stretch lasted for about 20 min.

This time a frequency sensor was newly added in order to mitigate the phase-frequency readout issue in the original phase frequency discriminator. The new sensor worked and gave a reasonable signal which then allowed us a smooth hand-off of the IMC length actuation from the IMC-PSL loop to ALS common loop.

The frequency sensor:

We added a new sensor for reading out the common beatnote signal. A cartoon diagram is shown below. With this sensor we are able to stably readout the CARM error signal which is encoded in the beatnote frequency. Some background are explained in the following paragraph.

It seems the reason why we hadn't succeeded in locking the CARM loop was due to the too advanced phase-frequency discriminator --- the discriminator switches its detection mode from the frequency sensor to phase sensor mode automatically depending on how far the frequency of the beatnote and VOC are apart. Ideally we want the phase discriminator to be within the phase sensor mode to achieve a high signal to noise ratio, although this requires a precision control of either/both the beatnote or VCO frequency to make them close to each other. Since the beatnote fluctuates more than the phase sensor range, the discriminator becomes frequency sensor and phase sensor back and forth, resulting in a unwanted noise due to a huge readout gain difference between the phase and frequency modes. When we stick this signal into the IMC length path, it kicks the IMC so hard that it unlocks the loop easily. So we guessed that the phase-frequency mode hopping was the issue preventing us from a smooth CARM lock.

Calibration and some characterization of PLL :

All the measurement was done by using a Marconi as a frequency source.

• df / dv = -14634 Hz / V
• d (counts) / df = 0.21 counts / Hz  (at H1:LSC-REFL_SERVO_IN1)
• locking range (or capture range) = +/- 50 kHz
• UGF = several 10 kHz ( just a guess, not measured)

The calibration coefficient df / d (counts) was put in the gain of H1:LSC-REFL_SERVO such that the signal is calibrated in Hz. A nice thing in this PLL is that even if the input frequency is out of the locking range, the phase frequency discriminator gives us a signal with a correct sign.

Funky SHG temperature control :

The SHG oven control was found to be off. So I turned it on. However engaging the temperature control didn't seem working properly --- probably the temperature sensor is not working correctly as the temperature readout doesn't change regardless of the TEC voltage. I quickly checked the cabling but no apparent issue was found. I decided to put a bias of 1.6 V in the TEC voltage so that the crystal is warmed up close to the optimum temperature of 35 degrees. This recovered the second harmonic power to approximately 100 uW from a couple of uW. Of coursed the temperature loop needs to be fixed soon.

Perhaps PSL frequency shifted :

After the PSL recovery (alog 6769) the PLL loop at the end station lost its beatnote. It is quite possible that the PSL frequency shifted so that it is locked to a neighboring resonance of the reference cavity since the PSL was in the process of reaching some sort of thermal equilibrium. I then went to the Y end station to adjust the temperature, which is generally not preferable. Anyway I ended up changing the laser crystal temperature from 31.33 to 31.83 degrees. This much of tuning brought the beatnote within the discriminators detection range and the PLL auto-locker started working.

Tuning of the end laser frequency :

I changed the frequency of the Marconi which drives the AOM in the fiber distribution box at the corner station. This was for bringing the green beatnote within the detectable range of the new frequency sensor. Originally the frequency was at 79.4 MHz and I changed it to be 78.9 MHz. As a result of the tuning the green beatnote became available within the ALS comm VCO range.

Handing off :

The screen shot below is the feedback paths of the MCL and CARM_MCL (namely LSC-MC and LSC-CARM respectively) which are mainly used during the hand-off process.

Here is what we exactly did to close the CARM loop :

1. Lock the PDH loop at the end station (done manually)
2. Lock the IMC (done by Chris's auto-locker script)
3. Dial the frequency of the ALS COMM VCO until the frequency sensor gets in the capture range (by hands but could be automated by ezcaservo or similar)
4. Start quieting down the CARM error signal by feeding the frequency sensor signal to MC2
   1. An initial gain of -0.001 in H1:LSC-CARM_GAIN was found to be smooth. The gain ramp time can be something like 1-2 seconds.
5. Engage a boost filter (FM3 of H1:LSC-CARM) to further quiet down the CARM error
6. Increase the CARM gain to -0.002.
   1. Be careful --- there can be an oscillation at 100 Hz if the gain exceeds -0.004
7. Fine-tune the ALS COMM VCO to get rid of some unwanted relative offset between the two loops
   1. This is done by looking at the H1:LSC-MC_OUT. We adjusted the VCO frequency such that the H1:LSC-MC_OUT becomes close to zero. This ensures that the two loops are not competing each other.
8. Decrease the gain of the MC loop H1:LSC-MC_GAIN slowly to 0.3 which is nominally 1.0 for the IMC locking.
9. Switch off the MC loop H1:LSC-MC loop by disabling the output.
   1. I think this doesn't have to be this type of sudden switch. It simply happened to be like this after several hours of trial.
10. Engage another boost (FM2 of H1:LSC-CARM) to make the CARM loop further stable
11. Done.

This handing process was found to be repeatable. The plot below is time series of the handing off.

Quick Assessments:

The resultant stability of the PSL frequency is still noisy and certainly noisier than the linewidth of the arm cavity ( ~ 83 Hz). In fact this is quite obvious in the middle right plot of the above time series where the infrared transmitted light of the Y arm (TRY) still passes through resonances even though the PSL frequency was stabilized. This is not surprising because we simply engaged the CARM control without any optimization of the noise performance. Plus the frequency sensor we are using is not something we originally planned to use. Plus, the fast control through the AOM additive offset is not yet introduced. These items must be addressed in the next week and hopefully we will have a much stable PSL light with respect to the arm cavity.

The loop transfer function needs to be analyzed and more sophisticated. We took a transfer function of the MC2 actuation loop when only the CARM was engaged by injecting a swept sine in LSC_CARM_EXC and taking TFs at right after and before of this injection point. The plot below is the result:

We interpreted this as the ordinary cross-over transfer function measurement --- if this understanding is correct, there is a unnecessary crossover at 53 Hz. This is consistent with our observation that increasing the gain by a factor of 2 leads to a 100 Hz oscillation. The control loop needs further modeling and sophistication.

Some settings :

Some importatn settings are saved as screenshots. They are attached.

• signal conditioning for the beatnote frequency (CARM_inputconditioning.png)
• settings of the REAL common mode servo board. Although the screen says it is a MC board it is not true (CMB_settings.png)

Attached are plots of dust counts requested from 5 PM June 13 to 5 PM June 14.

Both the dust monitor at location 14 in the LVEA (H2 PSL enclosure) and the dust monitor at location 16 in the LVEA (H1 PSL anteroom) are indicating calibration failures.

After retuning the ISI feedforward controllers (poorly tuned at the first try - https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6763) and slightly modifying the blend filters, I re-measured the motion of stage 1 and stage 2 in the following configuration:

Stage 1:
- Damping engaged
- Blend at 250mHz with T240 in the super sensor in all DOFs. 2 notch filters were added in CPS low pass complementary filters at 1.05Hz and 3.5Hz
- Isolation level 3 - UGF: 40Hz
- Sensor correction - STS-2 to stage 1 - In X, Y, Z directions
- Feedforward HEPI to stage 1 - X, Y, Z directions

Stage 2
- Damping engaged
- Blend at 250mHz in all DOFs. with and without notch filters. 2 notch filters were added in the CPS low pass complementary filters at 1.05Hz and 3.5Hz
- Isolation level 3 - UGF: 32Hz
- Sensor correction - stage 1 (T240) to stage 2 - In X, Y, Z directions

I have attached spectra of the stage 2 motion in the X&Y and Z directions. Except the at low frequency (below 100mHz), it is within requirements.

Gerardo, Kiwamu, Michael, Chris

I ended up breaking a pipe fitting trying to fix a small leak in the crystal chiller path, right next to the water filter on the return path. This was a pretty complex piece of piping (several fittings in a row) so instead of repairing the blue LXT pipe, Gerardo and I hooked up a length of red hose between the valve and water filter. This worked, but the flow sensor for the powermeters kept reading 0 and tripping the chiller - this happened last time as well. Kiwamu and I went inside to diagnose this and fix it. The first thing we did was to try and bleed the circuit by removing the supply hose to the box on the oscillator end for the powermeters, but when I tried to hook it back up, either the female quick connect fitting got stuck in the open position or some internal part came off on the male end. Either way about a quart of water started flowing onto the table, thankfully towards the edge of the table and not to the optics. We cleaned that up, filled the chiller, and got it running again. We did have to bleed this line once more, but this time we disconnected the hose from the manifold, not the oscillator box. This looks like the way to fix the problem - likely it's clearing an air bubble. The laser was then restarted.

Penultimate mass put into lower structure and moved into the welding area for alignment. Penultimate was hung on wire loop and pitch checked by eye against the structure. 440 stops were slid in and PUM sat down on them. Various earthquake stops were added around both PUM and test mass. PUM was aligned in pitch and roll. Test mass aligned in pitch, roll and separation from PUM. Looks to be pretty much ready for welding on Monday after doubling checking pitch and separation.

Angus, Gary, Travis, Betsy, Joe O'D, Doug, Jason

The corner timing frequency counter was swapped with a spare and is now working. The VCO readbacks were connected to the frequency counter inputs. This allows us to read back the frequency of all VCOs. The slow controls was updated to take advantage of the new readbacks and load them into the VCO structures.

J. Kissel, A. Pele

After closer analysis, the 0.43 [Hz] and 1 [Hz] boost filters recently added to the QUAD L damping loops were on the hairy-edge of stability. However, such levels of damping are *needed* on (at least the) 0.43 [Hz] mode in order to lock the HIFO-Y arm cavity (though admittedly, this has not yet been quantified). 

I've sense re-assessed the "Level 2" L design from 2013-05-01, this time making sure include the same extra boosts and taking the opportunity to tweak the P and R design as well. Further, instead of Matt's BSC-ISI model, I've used Vincent's latest best performance achieved on 2013-05-14 to have a more realistic estimate of the 0.43 and 0.56 [Hz] mode amplitudes.

I have not yet installed these filters, I'll wait on a time when it is convenient for fellow commissioners.

Details:
-------
Here's a summary of the changes from the 2013-05-01 design:
(Bode plot comparing the two sets of filters on pg 1 of dampingfilters_comparison_2012-05-01vs2013-06-14_MSvs2013-06-14_RS.pdf )

L: 
- Added additional 0p43 [Hz] resonant gain boost as designed (will replace "LOCK" filter)
- (Notably *did not* include 1 [Hz] resonant gain boost -- the 1 [Hz] isn't bothering anyone, and the filter destroys the loop's phase margin)
- Tweaked ellip_L to better isolate and align the notch, and to recover some phase needed after installing the new boost
    - Knee frequency from 5 [Hz] to 4.9 [Hz]
    - Stop band isolation from 30 [dB] to 31 [dB]
    - Q of notch from 15 to 10
R:
- Tweaked ellip_R to better align the notch (because there's plenty of phase with which to play, and with the new L and P filters, R sensor noise started to substantially contribute to the 10 [Hz] L total noise)
    - Knee frequency from 6 [Hz] to 5 [Hz]

P:
- Added additional 0p56 [Hz] resonant gain boost as designed (will replace "LOCK" filter)
- Tweaked ellip_P to better align the notch (because there's plenty of phase with which to play, and with the new L and P filters, R sensor noise started to substantially contribute to the 10 [Hz] L total noise)
    - Knee frequency from 6 [Hz] to 5 [Hz]


I attach the full set of design plots in case this design becomes permanent, but I'll draw your attention to a few plots in particular. Note, for a fair comparison, I attach one set of design figures of merit with Matt's BSC-ISI model used as input motion (dampingfilters_QUAD_2013-06-14_Level2p1.pdf), and one using Vincent's best ETMY data (dampingfilters_QUAD_2013-06-14_Level2p1.pdf), and compare all three in dampingfilters_comparison_2012-05-01vs2013-06-14_MSvs2013-06-14_RS.pdf. "_MS" is "Matt Seismic model" and "_RS" is "Real Seismic data."

Pg 1 of dampingfilters_QUAD_2013-06-14_Level2p1_RealSeismic.pdf:
(1) This new set of filters still meets the 10 [Hz] performance requirements, if not even a little-bitty-bit better because of the tweaks to the P and R loops 

Pg 5 of dampingfilters_QUAD_2013-06-14_Level2p1_RealSeismic.pdf
(2) The 0.43 [Hz] mode in L is now totally squashed, according to the loop design plot.

Pg 6 of dampingfilters_comparison_2012-05-01vs2013-06-14_MSvs2013-06-14_RS.pdf
(3) The pitch spectrum at the 0.43 and 0.56 [Hz] spectra is predicted to be about a factor of ~2 less with the new boost, and a factor of 4 less with real seismic data, at about ~5e-8 [rad/rtHz]. I'd love to install these filters and compare against optical lever signals, to see how my model is doing these days...

For the seismic kids:
(4) Pg 1 and 47:49 of dampingfilters_QUAD_2013-06-14_Level2p1_RealSeismic.pdf
Assuming ETMY BSC-ISI's performance at 10 [Hz] is representative of all BSC-ISIs (which we know is *not* true), what Vincent has achieved thus far is roughly equivalent to the sensor noise performance at 10 [Hz], and only dominates between 8 and 10 [Hz]. Nice! 

Pg 4 and 7 of dampingfilters_comparison_2012-05-01vs2013-06-14_MSvs2013-06-14_RS.pdf
(5) If you're really paying attention, you'll notice that the V and Y seismic noise has *changed* between 2013-05-01 and 2013-06-14_MS, even though I'm using the same M. Evans model. Why? Because of MIT and their silly "X Y RZ Z RX RY" ordering of the cartesian degrees of freedom. Don't ask. The newer representation, 2013-06-14_MS, is correct. And besides, I don't care any more about a model, I've got representative data of an awesomely performing BSC-ISI.

---------
The new filter design was performed by the script:
${SusSVN}/sus/trunk/QUAD/Common/FilterDesign/design_damping_QUAD_20130614.m

The comparison was done with the script:
${SusSVN}/sus/trunk/QUAD/Common/FilterDesign/compare_quad_dampfilter_design.m

Matlab representations of the new filters live in:
${SusSVN}/sus/trunk/QUAD/Common/FilterDesign/dampingfilters_QUAD_2013-06-14.mat
and the two new models (one with Matt's Seismic Data and one with Vincent's seismic data) are:
${SusSVN}/sus/trunk/QUAD/Common/FilterDesign/
dampingfilters_QUAD_2013-06-14_Level2p1_model.mat
dampingfilters_QUAD_2013-06-14_Level2p1_RealSeismic_model.mat
respectively.

For the input ground motion, I used the "GS13s, ST2, Isolation + Sensor Correction both stages" data, i.e. columns 21, 26, and 31 of
${SeiSVN}/seismic/BSC-ISI/H1/ETMY/Data/Spectra/Isolated/
'H1_ISI_ETMY_Spectra_XYZ_Comparison_Sensor_Correction_20130514_152000.txt'
'H1_ISI_ETMY_Spectra_RX_RY_RZ_Comparison_Sensor_Correction_20130514_152000.txt'
and calibrated by dividing the raw data by
cal = 1e9*squeeze(freqresp(zpk(-2*pi*[0 0 0],-2*pi*[pair(1,45)],1),2*pi*bscData.freq));

Alarms: Dust Monitors, CDS Frontend
Laser Hazard

Projected work:
End X electrical and computer work in air lock area
Crane RGA over X and Y manifolds
Fly HAM 1 door over X arm
Crane HAM ISI container over X Manifold

09:14 H1-PSL Chiller alarm – Michael R. added coolant to system.
Cheryl V. aligning MC-Trans on IOT2L
Jonathan H. and Jim B. moving wireless equipment from End-Y to End-X
Dave B, Hugo P, Chris W. recompiling H1LSC and H1ISC EY models 
10:30 Michael R. Transition LVEA to laser safe
10:35 Kyle R. opening GV2 and GV7 and soft closing GV8
10:53 Dave B. restarted the DAC
11:16 Patrick T. moving items to Mid-Y for storage
14:00 Kyle going to End-Y to turn off turbo controller
15:20 Dust alarm in Diode Room
15:34 PSL chiller alarm – Thomas V. and Michael R. working on chiller system

Known air leak on GV6 looks to be a "not insignificant" contributor -> Hope to look into this next week

I installed the feedforward from HEPI L4C to stage 1 of the ISI. The results are really good for a first try. Isolation at the resonance of the chamber around 8Hz is really improved by the feedforward. However, Isolation is deteriorated around 1Hz. With some tuning, it will be reduced.
I have attached the calibrated spectra of stage 2 motion in the X&Y and Z directions measured this morning. The damping, feedback, feedforward and the sensor correction were engaged in the best case.
 

Models were made for the ISIs of the Output Mode Cleaner yesterday. 

I made the related HEPI models today.

Those new models started this morning (both ISI and HEPI). The DAQ was restarted as well to account for the new channels.

The sitemap was updated, and safe.snap files were created.

All files (models, sitemap, macro substitution text files and safe.snap) are commited under the SVN.

This preliminary work will allow checking sensors on OMC ISIs and HEPIs, prior to the actual commissioning start.

Work was performed under WP3974 which is now closed.

For the 35W and 200W laser. 200W laser files end in -001.

The noise around 4 kHz is again present in the 200W laser's RPN plot, and it even shows up in the pointing measurement.

Hugo and Dave.

We started the first version of the HPI and ISI models for HAM4,5,6 this morning. h1boot's rtsystab file was extended. The DAQ master file was reconfigured for the new INI and PAR files. After two restarts due to channel duplication we were done by 11am (started at 10:33). The EPICS gateway did not reconnect to the DAQ cleanly, so I restarted the h1fe-cds gateway.

The DAQ has increased in size by the following

We have officially exceeded the LDAS 10MByte/sec limit.

Attached are plots of dust counts requested from 5 PM June 12 to 5 PM June 13.

Both the dust monitor at location 14 in the LVEA (H2 PSL enclosure) and the dust monitor at location 16 in the LVEA (H1 PSL anteroom) are indicating calibration failures.

[Mark B. Arnaud P.]

In the same manner as the previous changes on BSFM/QUADS, the calibration gain and sliders range of the TMSY have been modified for TMSY

Details :

In order to change the sliders range, the following adl file has been modified : SUS_CUST_TMTS_M1_OPTICALIGN.adl located in /opt/rtcds/userapps/release/sus/common/medm/tmts

It has been commited to the svn and a safe_snap file will be saved when isc team will allow it.

The calculation of the gains and offsets is detailed in TMSY_calibration.m located in /ligo/svncommon/SusSVN/sus/trunkTMTS/Common/MatlabTools and the 2nd picture, from Mark B.'s mathematica model has been used as a reference for M1 to M2 compliance in Pitch and Yaw (rad/N.m)

In order to reduce the motion of the quads at low frequency, I added resonnant gain filters called "LOCK" to the medm filterbank of etmy and itmy. Those filters are designed to help locking the cavity, damping the 0.43Hz and 0.99Hz resonnances of the first longitudinal modes and 0.56Hz of the first pitch mode. The stability of the closed loop hasn't been studied yet, but it looks to be working fine for now. The second and third pictures attached are showing the shape of the damping filters with and without the "LOCK" filter engaged. Those filters are engaged with a ramping time of 10sec.