The violin mode harmonics overlap with the ~15070Hz test mass bulk modes.  This may explain the mystery modes that have been rung up in the vicinity at Hanford alog27659 15063Hz and Livingston LLO alog20100 15085Hz.
This spectrum was taken from these measurements alog27743.  Two violin mode harmonics are visible between 15kHz to 15.1kHz and 15.5kHz and 15.6kHz.  Several test mass modes are also visible.  The violin modes were elevated and we were actuating on 15077Hz ITMX mode and 15072 ITMY mode (which are very large and far off the top of the plot).
 

Jenne, Sheila, Peter, Evan, Stefan

We had been using AS45I for SRM signal in the last two days, and they seemed to not work well for yaw today.  Peter and Jenne noticed that the violin modes showed up more strongly in some quadratns of the AS45 WFS than others, so we drove a line in DARM to check the balancing of the AS45 WFS. We drove DARM at 21 Hz, and  looked at the transfer functions to the individual quadrants before the phasing.  We set the gains so that the signal amplitudes would all match quadrant 1.  For AS A, we ended up with gains as different from 0 as 0.69

We then attempted to phase these signals in the same way that the LSC AS45 detector is phased, by turning on and off the DARM offset and making sure that all the DARM signal was in the Q phase.  To do this we changed some phases by up to 20 degrees.  We had to use a step size of 0.5degrees on AS A which is in loop for DHARD to avoid loosing lock.  

After doing this we tried moving the SRM alingment to see if the AS45 signals were better for SRM.  We saw that pit and yaw were cross coupled, and we didn't have much pitch signal at all.  We reverted these changes since we don't really think that the gains in the electronics can be this badly matched.  

C. Cahillane

I have revamped the uncertainty budget to include covariances between all stages of actuation and all time-dependent parameters.
I computed each parameter's covariances in real and imaginary coordinates to provide a consistent basis.  I then compiled an 6 x 6 Actuation Covariance Matrix C_A, a 2 x 2 Sensing Covariance Matrix C_S, and an 8 x 8 Kappa Covariance Matrix C_K.  Then I compile them into a giant covariance matrix C:

     _             _
    |  C_A  0   0   |
C = |   0  C_S  0   |
    |_  0   0  C_K _|     

Then, I multiply by some conspicuous Jacobian vectors J(f) to get the final 2 x 2 uncertainty matrix σ_R^2(f):

σ_R^2 = J * C * J'

where J looks like:

        _                            _
       |  d Re(R)    d Im(R)          |
       | ---------  ---------   ....  |
       | d Re(p_i)  d Re(p_i)         |
J(f) = |                              |
       |  d Re(R)    d Im(R)          |
       | ---------  ---------   ....  |
       |_d Im(p_i)  d Im(p_i)        _|

(I was able to use complex differentiation and Cauchy-Riemann here to make the derivatives easier.  Recall that R = 1/C + D*A.  Now I can compute dR/dA = D and dR/dC = -1/C^2 to form J(f), thanks to 200 year old mathematics)

Finally, to make the uncertainties readable by humans, I divide σ_R^2(f) by |R(f)|^2, rotate σ_R^2(f) by angle(R(f)) via a rotation matrix, and read off the square roots of the diagonal of the rotated σ_R^2(f) to get the magnitude and phase uncertainties plotted below.

I have plotted the uncertainty at GPSTime = 1135136350, the time of the Boxing Day Event.

The plot shows an overall increase in magnitude uncertainty of about 1% at low frequency.
Phase uncertainty increased by about 0.5 degrees at low frequency.

The effects are more dramatic at Livingston.  Check out LLO aLOG 26542.  

Jenne, Peter, Jeff, Terra

We took charge measurements on the ITMs by driving 20.1 Hz into H1:SUS-ITMX/Y_L3_DRIVEALIGN_L2L_EXC with 100k cts and looked at the coupling to DARM. We stepped up and down the ESD bias voltage from zero and found the bias that gave zero coupling to get charge measurements, where V_charge= (20/2¹⁸) * bias * 40. ITMX zeroed with bias = 3k, ITMY zeroed with bias = 2.5k. See bias stepping ITMX and ITMY spectra attached. 

ITMX charge: 9.15 V,   ITMY charge: 7.6 V

ITMX: 

ITMY:

Approximating alpha: The first term in the expression for the force produced by the ESDs is the attractive force between the ESD fringe fields and the test mass: F = alpha(V_bias - V_signal)^2, where alpha is a constant of proportionality. With the known bias voltage V_b, signal drive voltage V_s, drive frequency f, and now the peak amplitude x_pp , we used the largest bias offset (100k) to approximate alpha for both ITMs. Work is attached. 

ITMX: alpha = 1.78 x 10^-11 N/V²,   ITMY: alpha = 1.85 x 10^-11 N/V²

Stefan, Nutsinee

So we found out that the ITMY vstop filter has been turned off. That's likely the cause of mysterious ring up of ITMY violin modes last night and tonight. I was able to damp the three highest modes (ITMY MODE2, MODE3, MODE5) with the settings on the table I confirmed on June 13. I haven't had a chance to re-comfirm all the settings. So until then I would either comment out IY violin mode damping guardian lines or just skip it for now.

Wanted to get H1 to atleast DRMI before today's Press Conference, so jumped into locking first thing this morning, but no DRMI locks, and PRMI would not stay lock for more than a second, so opted for an Initial Alignment, but it wasn't trivial.  A few notes from locking & alignment:

1. Noticed an unlabeled Red Box on the OPS Overview at EY (PVinfo showed me it was the BIO for ETMy).  Ed showed me what this comes from (on the ETMy SUS screen's L2 stage all the way on the right, an LR box was RED for the BIO MON.  So, for the "RMS WD RESET", I changed the 1.0 to 0.0 and then back again to 1.0.  This cleared it up.
2. During the alignment, the IMC had issues:  1) Wasn't locking, 2) AOM Diffracted Power was a bit high over 12% (later found out this was ok), & 3) Cheryl noticed IO WFS YAW & PIT outmons were high.  For the latter, Cheryl hit "CH" for the YAW DOF filter banks (& also PIT).
   1. At this point, she noticed the PZTs were off, so she watched the MC2 Trans & video of MC REFL and walked the PZTs until she got the IMC locking.  This eventually brought back IMC locking
3. On PRM_ALIGN, the ASC signals never converged after a few minutes, so went DOWN & back to PRM_ALIGN & it was fine.
4. Also had issue with SRC_ALIGN, as noted yesterday, where once SRC_ALIGN_OFFLOADED looks to be complete, Guardian ramps the PSL down normally, but lately, it's been ramping it back up!  (anyway, took ALIGN_IFO node to DOWN & called it good).

Another IFO Note:  After the alignment, Krishna mentioned conditions were quiet so, we took the ITMs to the 90 blends and NO Sensor Correction.

BSC ISI Guardian Note:

Krishna noticed that Sensor Correction was turned off for ETMy & ETMx ISI's at around 1am last night by taking a gain from 1 to 0 by hand.  We want to get in the habit of not doing this (because Guardian does not monitor these gain channels -at the moment-), and use our fancy new Guardian medm (sitemap/O-1/ISI Blend Filters.adl)

Daily activity log attached as pdf.

I checked the PSL chillers, per FAMIS work order 4155, assigned to me today, and found the chiller was filled yesterday, so did not need any water.

First post is in the ground and concrete is curing.

1505 - 1520 hrs. local -> To and from Y-mid 

Opened exhaust check-valve bypass valve.  Opened LLCV bypass valve 1/2 turn -> LN2 at exhaust in < 1 minute -> Restored valves to as found

Next over-fill to be Friday, June 17th.  

Bad PEM corner station MAG and MIC channels

Richard, Fil, Robert, Dave:

We found that all the MAG and MIC corner stations channels have not been correct since the power recovery Mon 6/6.  These channels span several ADC cards, so it did not look like a software issue. However to rule this out we power cycled h1oaf0, its IO Chassis and the PEM AA chassis with no change to the signals. Problem was identified as two DC power supplies which needed to be turned on after the outages (18V for MAG, 36V for MIC). Robert confirms these channels are now good. We are still unsure why all the MAG and MIC channels read about 3000 counts on the IOP and not zero, we may investigate further next Tuesday.

h1calcs new code

Joe, Jeff, Dave:

new h1calcs model went in. Some channels were promoted from standard single precision floating point to the new double precision floating point data type. The RCG appends the suffix "_DBL_DQ" to these channels, compared with "_DQ" for standard chans. The channels changed are:

[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]
 

Initially H1:CAL-DELTAL_EXTERNAL was made double, but this meant the DTT display on the control room TV stopped working, this channel was then reverted to single precision.

ETMY Hardware Watchdog

Jim, Dave:

To verify the HWWD software is running, I pulled out the top monitor cable on the front panel of the EY HWWD unit. The LED fault light came on, showing that the software did start after the power outage.

DMT broadcaster channel configuration

Joe B, Maddie, Dave

Joe and Maddie requested some channel additions/removals from the DMT channel list, these were installed.

QUAD_MASTER change

Jeff

h1susetmx,y were restarted against a change to the QUAD_MASTER.mdl file. Next Tuesday QUAD_ITM_MASTER.mdl will be modified and the itm models restarted.

Resync of atomic clock to NTP GPS receiver

Jim:

Following the power outage, Jim re-synchronized the atomic clock to the 1PPS signal coming from the NTP GPS receiver. This provides an independent timing of the Timing Master.

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.

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)

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.