GWINC quantum noise curve is replaced with dynamically-generated shot noise curve. Radiation pressure will be included later.

The null stream spectrum shows 8×10⁻⁸ mA/rtHz shot noise, which seems to imply 17 mA of dc photocurrent on the sum, rather than the expected 20 mA.

Chris, Adam

We are going to start testing using tinj with the PCAL hardware injection filters.

Observing at 79Mpc.

Winds began to pick up a bit during alignment, but has since dropped back down to 20mph or below. Jim W wanted to change the blends for the end stations in the direction of the winds to the Quite_90s. So we did and seems to have worked well so far.

We have changed the blends for ETMX Y and ETMY X to the Quite_90 from the 45mHz.

The LHO DCS diskcache server froze this morning around 5 am PST. After several reboots failed to solve the problem, Dan Moraru reboot the main samfs file server too, and we restarted services, including condor, rds, and hoft aggregation and some Disk2Disk processes. All DCS services should be working again, and H1 summary pages should catch up soon.

SudarshanK, ChrisB, DaveB

We installed inverse anti-imaging filter on pcal hardware injection path, channel H1CAL-PINJX_HARDWARE, at FM3. The SDF screen and ODC bit are changed accordingly.

This filter will produce a better estimate of the  hardware injection  at higher frequencies.

Lockloss at 18:11 UTC

The winds have picked up slightly (20mph) and then the ETMX ISI starting moving in the X direction. It settled down for a moment, but then came back and after about 30 secs of some large swings, we lost lock. Jim W wants to try some different settings on the next go around.

Attached are the results of the charge emasurements taken earlier in the week.  Things look OK in charge land - some of the data points have a larger error bar likely because of added foot traffic at the end stations during maintenance.

The output power of the front end seems to have a ~20 minute oscillation in it.  Seems to
coincide with crystal temperature fluctuations.  The crystal fluctuations however do not
coincide with the flow rate.  I cannot determine if it is due to fluctuations in the crystal
chiller flow rate because we do not have enough resolution but the crystal chiller flow rate
appears to be constant.

The fluctuations do not seem to coincide with humidity either.  Nor room temperature.
Possibly fluctuations in the NPRO output power (FrontEndPowerOscillation6.png), it is
hard to tell.  There seems to be a small coincidence with the NPRO second pump diode
(FrontEndPowerNPROD2.png).  There does not appear to coincidence with any of the other 
NPRO signals monitored.

I should mention that the laser power mentioned here is prior to the power stabilisation
sensing.  The same fluctuation is not apparent in the reflected signal from the pre-modecleaner.

• TITLE: "11/12 DAY Shift: 16:00-00:00UTC (08:00-16:00 PDT), all times posted in UTC"

• STATE Of H1: Observing at 78Mpc for 16+hours

• OUTGOING OPERATOR: Travis

• QUICK SUMMARY: He had a very quiet shift, this is the same lock as the one I left Jeff with yesterday so it doesn't seem that the ISI swinging has returned.

Title: 11/12 Owl Shift 8:00-16:00 UTC (0:00-8:00 PST).  All times in UTC.

State of H1: Observing

Shift Summary: Smooth sailing all morning. Only a handful of ETMy saturations, but none related to any RF45 issues.  Wind is calm and microseism trending down slowly.

Incoming operator: TJ

Activity log:

10:40 GRB alert

13:45 GRB alert

15:41 Noticed an ETMy timing error on the CDS overview screen had popped up

15:43 Chris to X arm for beam tube sealing

Observing the entire shift so far.  A few ETMy saturations, but not related to any RF45 glitching.

Activity Log: All Times in UTC (PT)

00:00 (16:00) Take over from TJ
08:00 (00:00) Turn over to Travis 

End of Shift Summary:

Title: 11/11/2015, Evening Shift 00:00 – 08:00 (16:00 – 00:00) All times in UTC (PT)

Support: Jim W.

Incoming Operator: Travis

Shift Summary: A good low noise high range shift. IFO has been locked in Observing mode for the past 8.5 hours. Seismic activity has been low all shift. Microseism had been flat centered around 0.4 um/s for most of the shift, it has been slowly rising for the past 2 hours, and is now centered just below 0.5 um/s. The wind is calm to a light breeze (0 – 7mph). There were 3 ETM-Y saturations during the shift. There were no RF45 or ETM ISI CPS problems.    

I took a quick look at the swept sine measurements Chris made earlier today, in order
to derive a transfer function from H1:CAL-INJ_CW_OUT to H1:GDS-CALIB_STRAIN,
using the same matlab script written recently to analyze L1 measurements>.

Attached are spectrograms of H1:CAL-INJ_CW_OUT and H1:GDS-CALIB_STRAIN for
the period of the measurements, along with the derived transfer function
(see LLO alog entry above for explanation of graphs). Although there is an
odd bump in magnitude response at 610 Hz (due to compensating for a notch 
at a BS 2nd violin harmonic?), things are otherwise smooth between 200 and 1400 Hz,
albeit with phase wrapping at a bit more than 1000 Hz. This measurement seems
at odds with Matt Pitkin's CW hardware injections recoveries (summary plot attached), as is
the case for the recent L1 measurements. 

On the one hand, one could wonder if perhaps the swept sine just isn't sampling the frequency range
finely enough to catch everything that affects the particular frequencies where CW injections
are made, especially given the complexity of the inverse actuation filter Jeff posted here. 

On the other hand, the swept sine points were chosen to coincide almost exactly with
CW injection frequencies (575 and 849 Hz) for which discrepancies between injection 
recovery and the transfer function measurements seem to occur. 

Matt has double-checked and triple-checked the phase definitions he uses in 
injection recovery. So the discrepancies in phase for pulsar 1 and 2 phase remain
mysteries (for both H1 and L1). 

As discussed elsewhere, these lingering discrepancies suggest (to me, anyway) that we 
should simplify CW injections either by using PCAL with its considerably simpler IAF
or by dispensing entirely with an IAF in the current ESD injection mode (i.e., rescale
each CW injection amplitude by the point value of the inverse of the measured
actuation function).

Figure 1 - Spectrogram of H1:CAL-INJ_CW_OUT
Figure 2 - Spectrogram of  H1:GDS-CALIB_STRAIN
Figure 3 - Derived transfer function from H1:CAL-INJ_CW_OUT tp H1:GDS-CALIB_STRAIN
Figure 4 - Summary of CW hardware injection recoveries

   A good first half of the shift. IFO has been locked in Observing for the past 5 hours with a range around 78 to 81 Mpc. Seismic activity is quiet. The microseism centered around 0.4 um/s. Wind around the site is a light breeze (4-7mph). 

  There have been 2 ETM-Y saturations. There have been no ring up of the ETM ISI CPSs.      

In my previous entry 23283 I only reported results for 3rd and 4th harmonic because for the 21 hours of data analysed there the damping filters of the fundamental and second harmonics for the test masses were activated.

As described in 23085 on 2015-11-04 we were allowed to turn off the damping filters for the fundamental and 2nd harmonics of ITMX and ITMY and we managed to get a 10 hours continuois lock of the detector. This happened from (UTC) 2015-11-04 06:35:00 to (UTC) 2015-11-04 16:15:00. (See attached plots of the damping filter GAINs nulling during the interval of interest and a detector state graph showing lock during the time of interest).

I looked at channel H1:OMC-DCPD_SUM_OUT_DQ downsampled to 8192Hz in order to be able to handle the considerable amount of data.

The attached spectrum of the 10 hours of data on a 0.5mHz resolution and 33 averages identifies (in red) the dominant peaks at the fundamental violin mode frequencies corresponding to the violin modes previously assigned to ITMX and ITMY (as per 17610).

Like in 23283 I used a line tracker (iWave) to track the frequency and amplitude of each fundamental mode of the violin modes of ITMX and ITMY. Attached are the summary plots for the locked modes at the top is the frequency as a function of time and at the bottom is the Log of the amplitude as a function of time. A first order polynomial is fitted to Log(Amp) in order to obtain the Q of that mode.

Looking at the iWave plot results we observe that very few modes show a clear ringdown (these are highlighted in bold on the table below), also some modes show actually an amplitude increase:

            Frequency                       Q                Delta_Q

   1.0e+09 *

   0.000000500053540                   0                   0

   0.000000500211188                   0                   0

   0.000000501090622   1.099263893173578   0.001406678163595

   0.000000501206991   0.387149689289317   0.000525686495200

   0.000000501255024                   0                   0

   0.000000501451642   0.836253670431456   0.000578382636001

   0.000000501607755                   0                   0

   0.000000501684000                   0                   0

   0.000000501748284                   0                   0

   0.000000501811170   0.672273711595517   0.000373649058032

   0.000000502622036                   0                   0

   0.000000502745387   0.287935668815574   0.000095512884649

   0.000000503007120   0.296739931868312   0.000046580713516

   0.000000503119439                   0                   0

   0.000000504805141                   0                   0

   0.000000504871717                   0                   0

NOTE: The Q of the trustworthiest ringdowns in this analysis are between 0.3 and 0.8 e9, in comparison with the 3rd and 4th harmonic measurements in 23283 which range 0.6 and 1.5 e9.

Kyle, Gerardo 

Today we closed the 10" gate valve at BT port X2-8, vented the port-side, removed the existing hardware and coupled the new ion pump and hardware to it.  We then pumped out the new volume with the leak detector and helium leak tested the new joints.  This unit is part of the overall ETM charge mitigation efforts taking place at both sites.  A similar unit was installed at BT port Y2-8 a few months ago.  Both of these units still need to be baked-out and tested before being available for use.  We plan on doing so over the next few weeks.  

I have turned off the violin mode damping filters for IX and IY by zeroing their gains. Patrick accepted these into SDF so that we can go to observing.

This is meant to be temporary, i.e., for this one lock only.

The next time the interferometer comes into lock, the Guardian will turn on the normal violin mode damping settings. These settings will appear as SDF diffs (two on IX, and six on IY). These should be accepted into SDF.

We do not expect these modes to ring up during the course of the lock. However, if the mode height on the control room DARM spectrum around 500 Hz rises above 10⁻¹⁶ m/rtHz, the damping should be turned back on:

1. Make sure the ramp times for the damping filter modules are at least a few seconds (currently they seem to be set to 10 s).
2. The filters should already be configured to provide the right damping phase, so changing the filters should not be necessary.
3. Start typing in gain settings. Refer to the values listed below. If the violin mode amplitude is much much higher than usual (e.g., it's off the scale on the control room DARM spectrum), it is wise to start with a small gain (e.g, gain of ±1) in order to make sure the suspension drive does not saturate. Then you can increase the gain in several steps, until the nominal setting is achieved.

A screenshot of the nominal IY damping settings is attached (I didn't take one for IX).

ITMX:

• MODE3 gain: −100
• MODE6 gain: +200
• all others zero

ITMY

• MODE1 gain: −200
• MODE2 gain: −200
• MODE3 gain: +100
• MODE4 gain: −50
• MODE5 gain: +400
• MODE6 gain: +50
• all others zero