Michael, Jim, Krishna

We had 20-40 mph winds for most of the day yesterday. In the evening we tested a couple of different ISI configurations at the Corner Station (ITMX, ITMY) and the End-Stations. We tested the following two configurations:

1. 90 mHz Blends on ST1 and no sensor correction (SC) on all test-mass chambers -  The standard configuration used for most of O1 which works well in low microseism.

2. 250 mHz Blend and BRS SC on ST1 at the End-Stations and 90 mHz blends and no SC on ITMX, ITMY - The idea is to use the tilt-subtracted ground seismomter in feedforward more and rely less on the tilt-contaminated ST1 seismometer.

Quick Answer: The effect on some of the Interferometer channels we looked at was a small but uniform improvement of a factor of ~1.5 or so over the 90 mHz blend configuration. Near 0.1 Hz we were limited by ITMY chamber motion.

Details: The first attached pdf shows some of the Interferometer channels in Config 1 (Dashed) versus those in Config 2 (Solid) in units of ADC counts. The red line is equivalent to H1:DARM_CTRL_OUT_WHITEN_DQ which for some reason was not available today. The other three lines are some of the Angular Control Signals, all of which show small improvements. The second page shows the ASD of the wind-speed in both Configs showing that wind-speeds were comparable during the two measurements.

The second pdf shows data from some of the ISI local sensors. The first plot shows the ground motion near each chamber - note that the ITMY seismometer sits in the 'bier garten'  which is far away from the walls of the building. Also shown are the tilt-subtracted super-sensor signals (dashed lines). It is worth noting that the secondary microseism becomes visible after tilt-subtraction and is consistent with what the ITMY seismometer measures. The next plot shows the CPS signals which at low frequencies, are representative of the motion of ST1. The combination (ETMY-ITMY)-(ETMX-ITMX) should roughly correlate with DARM_CTRL at low frequencies, since the translational ground motion is small below the microseism. The third plot shows the ST1 seismometer(T240) motion. In all these plots, notice that despite the apparently quieter ground motion, ITMY moves nearly as much as ETMY. This is also seen in the fourth plot - which shows the coherence of the DARM_CTRL with the various CPS sensors. ITMY shows significant coherence between 60 to 200 mHz.

I think this suggests that the ITMY seismometer may not be a good measure of the tilt of the ITMY chamber, which is closer to the walls of the building. Thus our assessment that the Corner tilts significantly less than the End Station may not be valid. But if ITMY seismometer acts as a nearly tilt-free seisometer we can use it for sensor correction just as we do at the End-Stations and gain another small factor of ~1.5-2 in low frequency DARM_CTRL.

(Richard, Gerardo)

Landed cables at rack and at the controller for annulus ion pump 525 (BSC5 AIP), gettind data now.

For future reference at the rack for both X-end and Y-end:

F37 ------- 011(+)

F38 ------- 012(-)

Added 231 channels. Removed 74 channels. (see attached)

The following channels are still unmonitored:
H1:GRD-TCS_ITMX_LOGLEVEL
H1:GRD-TCS_ITMX_MODE
H1:GRD-TCS_ITMX_NOMINAL_S
H1:GRD-TCS_ITMX_REQUEST
H1:GRD-TCS_ITMX_REQUEST_S
H1:GRD-TCS_ITMX_STATE_S
H1:GRD-TCS_ITMX_STATUS
H1:GRD-TCS_ITMX_TARGET_S

• 8:00am - 12:39pm Maintenance (summary here)
• Univ of Washington At Bothell tour led by Landry in the afternoon.
• Commissioners took H1 in the afternoon.

Kiwamu, Jeff, Evan

The calibration group has known since O1 that Hanford (but not Livingston) has an anomalous loss of gain in the DARM optical plant at 10 Hz and below. This can be explained by 0.5° of positive (antispring) SRC detuning away from pure RSE.

The first attachment shows a loop-corrected pcal sweep from O1, calibrated into mW/pm. On top of this I have plotted my guess at what theory curve this corresponds to (from Rob Ward's thesis), using 700 W of beamsplitter power, an arm pole of 42 Hz, an SRM transmissivity of 37 %, a homodyne angle of 90°, and a one-way SRC carrier phase of 90.5°. (The theory curve is pretty much insensitive to variations in the homodyne angle at the few-degree level, and we know that the homodyne angle deviates from 90° by less than 3°, since we ran with 20 mA of dc offset light and there is less than 1 mA of contrast defect light.)

To test this, I took a new set of pcal sweeps at 10 W of input power, with several different SRC detunings. The result is shown in the second attachment, again with guesses about the theory curves. All are with 350 W of beamsplitter power, 42 Hz arm pole, 37 % SRM transmission, and 90° homodyne angle. 0 ct of SRCL offset corresponds to the green (90.8°) curve, –200 ct corresponds to the blue (90.1°) curve, and +200 ct corresponds to the red (91.5°) curve. The implied calibration (0.1 ct / pm for the SRCL error point) is consistent with SRCL OLTF budgeting. The fact that 0 ct of SRCL offset produces a nonzero RSE detuning is perhaps not surprising, since we have never had good angular control of the SRM.

With the list of items on our plate and the need to give more time to getting H1 ready for ER9, we did our darnedest to limit Maintenance Day to 4hrs today.  Jeff helped from the Detector Engineer side, and Ed was recruited whenever the waves of activities were too much.

With Maintenance starting at ~8:00, we were complete by around 12:39pm.  At this point, it was noticed that the Quads were pretty misaligned.  I restored their pointing via Oplev trends, and then since there were big changes, I went ahead and performed an Initial Alignment.  

Ops Note:  Only issue with alignment was when doing the last step (SRC_ALIGN_OFFLOADED).  For some reason, the IMC would break lock and Guardian would loop through this step repeatedly.  Not really sure what the issue was here.  Sheila & Jenne were notified of this.

Alignment took from 12:39pm - 1:44pm & then handed over to Commissioners.

A log of all activities are attached as a pdf (vs posted in this alog......thought of reducing alog real estate with the many lines of each activity during the day---input on preference on how Operators should post logs like this would be nice).

At 18:00 utc I decreased the LLCV valve setting to 18%, previous setting was 20%.  Due to LN2 delivery today.

Added 300 mL H2O to the H1 PSL crystal chiller. There were no fault alerts on either chiller. Both canister filters appear clear.

Gerardo, Chandra

Adjusted the potentiometers of the following pirani gauges (3-8 turns in CW direction) to calibrate pressure reading to ~5e-4 Torr.

PT-100
PT-110
PT-114
PT-134
PT-210

I replaced the razor blade beam dump that was being used to dump the p-pol beam (rejected beam in the MCR path) with two steering mirrors and a Kentek Trap-it.

The p-pol beam will be a minimum of 1.2W at 50W input power, and about 0.8W at 30W input power.

Removed: IO_MCR_BD6 razor blade dump

Added: steering mirrors IO_MCR_M14 and IO_MCR_M15:

• Newport: 10QM20HM.10
• 1/10 wave
• 0deg
• R(s-pol) > 99.7%
• R(p-pol) > 99%

Added: IO_MCR_BD6 high-power beam dump

• Kentek Trap-it beam dump
• model: ABD-3/4 inch aperture
• max. power 50W

With this upgrade completed, I've modified the IOT2L layout drawing to include the new components, and updated the version to D1300357-v3.

Attached: 

• new components - view from the front of the table
• new components - top view

15 days trend data for the 3 IFO storage containers attached.

New today is the the SEI_CONF Guardian node that will manage all of the other configuration nodes that we have made the past few weeks. This will hopefully make it much easier to choose a configuration for all of SEI. Sensor Correction for the entire SEI can be turned OFF from here, and then be brought back, of course.

The states and their names are very likely to change in the near future. So keep an eye out for updates, and we will also try to keep documentation up to date.

I also move the GUARD_OVERVIEW.adl around a bit since it was getting crowded in spots.

Modified the PUM Chassis by connecting pin 2 and pin 18 on the binary input DB37 connector. This was to address the issue of the binary RMS reset not working. See alog 27633. We confirmed this modification was already done at EY. Next Tuesday we will need to verify the ITM units have this modification.

We also confirmed that R111 had the correct value of 100K on all four channels.

David.M, Jenne.D, Jeff.B

This morning we set up 6 L4Cs in the 'beer garden' area of the LVEA. They are positioned close to the STS-2 there, with three on the concrete and three on the linoleum surface (see attached photo). This should enable us to determine the effect of the linoleum coating on the L4C output spectrum.

I've attached a screenshot from Diagnostic Test Tools plotting the power spectrum of all 30 L4C channels. Only the 7th L4C channel (H1:NGN-CS_L4C_Z_7_OUT) shows a seismic response. The other channels only show ADC noise, however there should be 6 sensors connected. Early tomorrow morning I'll perform some checks to try and diagnose where the problem is.

I looked at last night's increase power lockloss, and can see that the lock broke right when the IMC common mode board gain slider moved. (plot attached).  For now I've changed the gain adjust function in the IMC guardian to make 2dB steps instead of 1dB. 

J. Kissel

Charge measurements are complete for this week. As predicted last week, we're now ready to start the trial period of regular requested ESD bias voltage flipping. I'll work on the script later today after maintenance has died down.

Ross, Terra, Carl, Tega, Jim, Dave, Matt, Ed, Daniel.

In this alog we report on some of the simulink model changes made in relation to PI work carried out at LHO during the period spanning April to 10th of June.

We currently have two possible error signals for PI damping: the trans-QPDs and the OMC DCPD signals. The trans-QPD signal is more readily available to drive the ETMs, whereas the OMC DCPD signal is more readily available to the ITMs. Since the OMC DCPD signal has a better SNR compared to the trans-QPDs, it can be used to monitor the modes lines before they ring up. The main limitation of the OMC error signal lies with fact that its fidelity may change with better alignment of the X- and Y-arms.

There are currently three different strategies for PI damping in the suspi models, all of which have been implemented in the end station suspi models (h1susetmxpi and h1susetmypi).

The first takes data from the trans-QPDs, processes the data using a band-pass filter and a PLL (iWave) and sends the output to the ESD driver. This is the top-left block in the suspi models called "ETMX_PI_DAMP". It comprises 8 modes blocks each one of which contains an IWave PLL block for dynamic line tracking. The down-conversion block immediately below the trans-QPD mode block provides the means for sending the trans-QPD signals to the corner station (the data transfer for this has not been implemented yet).

We have also adapted the iWave line tracker to PI damping. The simulink model shown below provides the means for the user to enter a threshold value above which the we maximally damp and below which we damp proportionally. There is also a modified IWAVE_AMPCTRL block (in userapps/sys/common/models/IWAVE.mdl) that damps the mode to a manageable level that is again specified by the user so that we can continuously monitor the mode power in the error signal. This block is not currently deployed but should be amongst several variations of PI damping to be tested in the future in order to down-select to the best configuration.

The most recent test of this system shows that updating the parameters (SINGAIN, COSGAIN, frequency) of the remote oscillator introduced considerable noise. A short term solution---aimed at demonstrating the viability of the system---is the reduction of the rate at which we update the oscillators. This is the role of the sample-and-hold block in the monitor block below. Whilst the system has been shown to work successfully with this modification, further work is required to realise the full potential of this scheme. For example, some of the amplitude noise in the I and Q values can be eliminated by the constraining them with the tracked amplitude from iWave. This would be particularly useful should the I and Q values suffer the same distortion from the update of the fixed oscillators frequency in the omcpi model (h1omcpi).

To get the signal parameters (I, Q, frequency), we use a modified version of the iWave block that incorporates a fixed phase oscillator. Here, the oscillator serves two main functions: extraction of the I and Q values and providing a dynamic band-pass filter around the mode line of interest.

At the end station, we have companion oscillators whose parameters (SINGAIN, COSGAIN, frequency) we update via EPICs for proof of concept. We note that the first mode uses a slightly different architecture. This was part of the debug process intended to test whether an indirect update of the I and Q values of the oscillators reduces the noise at the output. So far this does not seem to be the case. Although this system currently uses EPICs, this does not have to be the case. The low bandwidth nature of the update means it can be readily added to the existing PI channel for moving the data between the corner and the end stations.

We have also adopted the MIN_MAX_CALC CDS library part for monitoring power build-up of PI modes over a wide range of frequencies and should be deployed shortly. The monitor block resides in userapps/sus/common/PI_MASTER.mdl.

Presently, there is no mechanism for dealing with multiple lines that are separated by less than 1Hz, so we have adapted iWave to function as a user configurable static and dynamic notch filter. These blocks reside in userapps/sys/common/IWAVE.mdl. The idea is to place at least one notch filter in series with iWave in the PI mode block and have it operate in static mode by default. Although preliminary work done on the test stand shows that this does not impact on the performance of the mode block in the absence of any nearby lines and stabilises the behaviour of the iWave PLL in their presence, further work is required to fully stress test this system against wandering lines that cross one another in the frequency domain before deployment.

Evan, Sheila

Earlier today we had several locklosses while trying to engage the soft loops which may have been because SRM was uncontrolled and the POP90 power increased.  

We searched for a better error signal for a while tonight, we looked at dither SRM and demodulating DARM (low SNR), demodulating SRCL (good signal but a large offset), POPX, some REFL WFS.  

Finally we decided to try AS45I, where we had a reasonable signal with a zero crossing that gave us good sideband buildups for both pit and yaw.  For pit we are using 1*ASA45I +0.76*ASB45I, while for yaw we are using ASA45I+ASB45I.  The guardian is engaging these with a gain of -300 in SRC_ASC, which has worked once.  It allowed us to turn on the soft loops and corrected the sideband buildups.  

Overall violin modes situation improved by a little more than an order of magnitude. Currently the modes with highest magnitudes are 501.092 (IX Mode3, lost lock before I could find the damp setting), 501.606 (IY, damp setting found but didn't have much time to damp), and 507.194 (EX, no damp setting yet).

Modes with newly discovered damp settings:

505.71 & 505.707: EX Mode3: FM1, FM2, FM4, FM5 +20 gain seems to work for both lines. After I noticed the filter stopped damping I turned off Mode 3 gain and turned on Mode2 gain based on Sheila's configuration here. This configuration will damp the modes even further. We lost lock before I could confirm that it won't blow either .71 or .707 up.

505.587: EX Mode1: FM1, FM4 +50 gain

507.159: EX Mode6:FM1, FM4 +gain (forgot to write down how much gain exactly. Probably no more than 100)

507.391: EX Mode8: FM1, FM4 +50 gain

500.05: IX Mode1: FM1, FM4, +50 gain. +100 gain will damp the mode but later will blow it up. +50 gain seems to have worked pretty well.

502.744: IX Mode8: FM1, FM3, FM4, +10 gain (BP, +60deg, 100dB)

502.621: IX Mode7:FM1, FM4 +50 gain (BP, 240dB)

501.606: IY Mode1: FM1, FM2, FM4, +150 gain

All these information has been updated to the new violin mode table but haven't been implemented into the guardian.

Tonight I also confirmed all the filters that VIOLIN_MODE_DAMPING Guardian turns on (I didn't confirm the exact gain, but I did confirm the filter configuration and gain signs). They should be safe to turn on.

Carl, Terra, Ross, Tega

Tonight we used the freshly installed LVLN ITMX ESD driver to ring up and damp two mechanical modes of ITMX, 15063 Hz and 15077 Hz. 

After sorting out some phase settings, we drove the ITMX ESD close to saturation in a differential drumhead pattern. Negative gain rang up 15063 Hz. Flipping the gain sign to postive then damped this mode and rang up 15077 Hz. The amplitude plateaued as a the saturated drive signal approched a square wave. Figure below tracks amplitude of 15063 Hz and 15077 Hz (seen in OMC trans), with gain sign flip occuring around the 0.15 time mark. 

Also attached is a spectrum of H1:OMC-PI_DCPD_64KHZ_A_DQ during no gain, negative gain, and positive gain times, i.e. on either side of the 0.15 time mark from the plot above. 

At about 0.23 hours the gain was turned off and the mode rangdown.  The fit to this ringdown indicates the mode has a Q factor of (omega_o)/(2alpha) = 1.2 million.  

Settings: Power 1.9 W, DC bias 100k, butterworth BP filter, iWave bypassed, -60deg damp filter, damp gain 300,000.