The Timing Solutions time code generator in the MSR has been resync'ed to the Symmetricom NTP server following the power outage of June 4,5.  The following steps were performed:

Sync the Symmetricom 4310B Cesium Frequency Standard to the Symmetricom S350 NTP Server.

Attach the 1PPS output of the Symmetricom S350 NTP server to the Sync input of the Symmetricom 4310B Frequency Standard (aka atomic clock). Attach matched coax cables from the Sync input of the 4310B and the 1PPS Out of the 4310B using coax T's to an oscilloscope to measure the difference between the two signals.  Difference between sync pulse and 1PPS out was 178mS.  Send sync arm command to the 4310B via the RS-232 input to the 4310B.  Observe that the difference between the sync pulse and the 1PPS out of the 4310B is now in the range of 30nS.  Note that the jitter of the S350 is much greater than the output of the 4310B, so precise measurement is not really possible to the 1nS range.  Also, it's only possible to sync the 4310B to a 1PPS input to +/- 100nS.

Sync the Timing Solutions timing distribution system to the 4310B.

Next, attach the 1PPS out of the 4310B to the Timing Solutions TCG 1PPS Sync Input. Using the oscilloscope, measure the difference between the TCG 1PPS Sync Input and the TCG 1PPS Output.  This difference was in excess of 430mS.  Adjust the slew using the Timing Solutions MCA user interface to bring the difference as small as possible.  This involved several iterations as it is only possible to adjust the slew by a maximum of 100mS for each adjustment. Also note that the minimum adjustment is 10nS.  The ending best difference obtained was 4nS between the 4310B 1PPS output and the TCG 1PPS output. The 4310B 1PPS output is connected to the TCG Advance 1PPS input to monitor coincidence to +/- 20nS between the 4310B and TCG 1PPS.  No adjustment of the Timing Solutions TCT units at the end station is needed, as the only adjustment possible is to compensate for the length of the optical fiber between the corner and end stations which is a fixed value.

The 1PPS output of the Timing Solutions TDS is connected to the corner station timing comparator input 1 while the Symmetricom S350 NTP server is connected to input 2.  The MEDM screen for the timing comparator shows the difference between the timing master 1PPS derived from a separate GPS receiver and the various inputs.

Subsytem Updates

• SEI:  Continue configuration investigations related to environmental conditions (Krishna)
• PSL:  DBB work from yesterday update (Peter)
• SUS:  Installed new oscillators on quads.  (Jeff K)
• PEM:  vault seismometer investigation (Robert)
• facilities:  wind fence and sealing beam tube enclosure
• VAC:  Pots adjusted on piranis (Chandra)

REMINDERS:  

• Be mindful of commissioniner work.  No incursions into VEAs without notifying operator.
• Close out Tues Maintenance Work Permits.

Progress on the E X Wind Fence. We will continue work on this project today also.

Carl, Terra, Rich A.

1. We used the never-before-tested LVLN ITMY ESD driver to ring up and damp two mechanical modes of ITMY, 15072 Hz and 14979 Hz. Below is the amplitude evolution of the 15072 Hz peak as we rang it up, allowed it to ring down naturally, rang it up again, and then damped it down fully with a gain sign flip. 

We drove and damped similarly for the 14979 Hz peak. 15072 Hz is the vertical differential drumhead mechanical mode; 14979 Hz is the horizontal version. For both cases, we tightly bandpassed the H1:OMC-PI_DCPD_64KZ_A/B signal, added a +60deg damping filter, and added gain to the damping filter until saturation. Positive gain drove up, negative damped down. 

I've fit the natural ring down with f(x) = a * exp(bx), where tau = - (1/b). Then Q = pi * 15072 * tau = 31.5 million.

2. Interestingly, we realized after the above tests that we had not turned the ESD bias on for either ITM. After turning on both to 100K cts (to DC offset), we just had time to ring back up the ITMY 15072 Hz mode before a lockloss. Below is a comparison of the ring ups (note we lost lock and did not damp for the ring down portion below). Green trace is the 15072 Hz ring up without bias, blue trace is with bias (time shifted for ease of comparison).  

A slight slope difference is visible but we'll look into this more. Thoughts are that we could use the difference in responses to measure test mass charge coefficients as discussed here and here.

3. We turned ring heaters off and on for future mode-mass identification analysis. For the record (since RH messing with violin modes was a concern tonight):

• 2:36 UTC ETMX RH turned off (ITMX RH was already off)
• 3:00 UTC ETMY RH turned off (ITMY RH was already off)
• 3:32 UTC ITMX RH turned on (0.5 W top and bottom)
• 4:03 UTC ITMY RH turned on (0.5 W top and bottom), ITMX RH turned off
• 4:39 UTC ITMY RH turned off
• 5:56 UTC both ETM RHs turned on (0.5 W top and bottom)

Stefan, Nutsinee

A very quick summary: ITMY modes rung up tonight. All the damp settings has been changed. I suspect ETMX damp phase might have been changed as well. ITMX didn't seen to have a problem. We suspect the ring heater changed the violin mode frequency.

Below I attached a screenshot of what works on ITMY modes tonight.

Sheila, Haocun

We had lots of locklosses today, and some were probably caused by the side OSEM driving of the beamsplitter M1, as shown in the figures attached.

(H1:SUS-BS_M1_MASTER_OUT_SD_DQ & H1:SUS-BS_M1_DAMP_T_IN1_DQ)

J. Kissel 
WP #5932

Today's model modifications come in three parts: 
(1) Independent Synchronized Oscillators for each isolation stage of the QUAD for calibration lines
(2) Updated CAL-CS model with better demodulation scheme that spits out coherence and uncertainty
(3) Changed all CAL-DELTAL and CAL-DARM channels to double precision and removed whitening
Below are all the details.

------------- Part (1)
In order push the PCAL vs. SUS actuation calibration line cancelling scheme for ER9/O2 forward (see T1600218 and T1600215), I've installed independent, longitudinal, synchronized oscillators in each of the UIM/L1, PUM/L2, TST/L3 stages of all of the QUAD models. See first attachment for screenshot of the QUAD OVERVIEW screen that now has the CAL_LINE block beneath every LOCK bank. Sadly, due to the recent split in QUAD library part models, I'd forgotten to add the needed EPICs channel for GPS synchronization to the ITMs. We'll install them tomorrow morning. 
I've committed the following new models: 
/opt/rtcds/userapps/release/sus/common/models/
Sending        FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl    <-- Used in PUM/L2 stages
Sending        FOUROSEM_STAGE_MASTER_OPLEV_TIDAL.mdl              <-- Used in UIM/L1 stages
Sending        QUAD_MASTER.mdl                                    <-- Added EPICs record for GPS sync time on TST/L3 stage for ETMs

and accordingly modified MEDM screens:
M       SUS_CUST_QUAD_ITM_OVERVIEW.adl
A  +    SUS_CUST_QUAD_ISTAGE_CAL_LINE.adl
D       SUS_CUST_QUAD_L3_CAL_LINE.adl
M       SUS_CUST_QUAD_OVERVIEW.adl


------------- Part (2)
In addition, as a continuation of the improvements to using those calibration lines to track changes in the DARM loop parameters, I've followed Joe's instructions (see LHO aLOG 26491) and updated the CAL-CS model to demodulate PCAL and DARM error signals at given frequencies and produce parameter estimates, coherence estimates, and even uncertainty estimates. 

Darkhan will be working on commissioning the infrastructure with Joe.


------------- Part (3)
Finally, I've converted all of the calibrated DARM channels to double precision. *EXCEPT* for DELTAL_EXTERNAL, which is needed to display on the wall in the control room via DTT (which sadly, cannot yet handle double precision; see CDS Bug 1003).  

As a result, and as per Joe's advice I've turned OFF all dewhitening filters that condition the following (new) channels stored in the frames: 

H1:CAL-DARM_CTRL_WHITEN_OUT_DBL_DQ 
H1:CAL-DARM_ERR_WHITEN_OUT_DBL_DQ 
H1:CAL-DELTAL_CTRL_DBL_DQ  
H1:CAL-DELTAL_CTRL_PUM_DBL_DQ  
H1:CAL-DELTAL_CTRL_TST_DBL_DQ 
H1:CAL-DELTAL_CTRL_UIM_DBL_DQ  
H1:CAL-DELTAL_RESIDUAL_DBL_DQ  

We need to investigate if we're now happy with the signal fidelity without whitening or if we just need to re-assess the whitening. Again, I've retained single precision on H1:CAL-DELTAL_EXTERNAL_DQ, so its whitening filter remains ON.

The ITMY PI path was measured during maintenance day driving from CDS and measuriung the quadrant outputs to the ESD. WP#5931
Specifically driving H1:SUS-ITMX_PI_OMC_DAMP_MODE2_DAMP_EXC, and measuring P2-P5 of D1600122 directly with an SR785.

Generally behaves well.  The LR channel has slight excess noise (about twice the other channels) which is a ~65kHz signal.  It goes away when the DAQ input to the box is removed.   There was no evidence of the glitchy behaviour of ETMX LR channel.
Other than that it looks just like the ETMX.  The electronics TFs slightly over estimating the HF voltages. 

Anticipate running this pump for then next week or two.

I've started a test Conlog process on conlog-test-replica connecting to the same channels as the production Conlog process on h1conlog1-master.

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.

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.