Found the water level on TCS-Y chiller to be just above the zero level. I added 1420ml to bring up the water level up to the 3/4 level. Before today, water added was 40 days ago. TJ and Jason checked the system lines and found no apparent leaks. TJ is going to take a look on the table.
The machine h1hwsex was pinned to run kernel 3.19.49 which is the newest kernel that successfully work with the hws camera, previeusly it was trying to run 3.19.78 on boot, but we removed that option from Grub. see work permit number 7128
WP7127 Daniel, Dave:
we powered down h1ecatc1, installed a second ethernet PCIe card in the second slot down on the full card size side, and powered the computer back up.
WP7126: Dave:
The BIOS setting on h1susey was modifed in an attempt to stop the periodic ADC glitching seen on these faster computers. Gerrit at AEI discovered that disabling the 'turbo' cpu mode fixed the glitching.
The BIOS path to the relevant screen is Advanced -> CPU Configuration -> CPU Power Management Configuration
The 'Power Technology' item was changed from 'Max Performance' to 'Disabled'
Before this change both h1susex and h1susey were glitching (approximately several times per day), now hopefully h1susey will stop glitching.
Unfortunately, even though I manually took h1susey out of the Dolphin fabric, and ran its power off script, it still glitched the EY Dolphin on restart. All models on h1seiey and h1iscey needed to be restarted. For now on we will assume this glitching can happen and put SEI into its SAFE state before rebooting SUS.
The CPU usage of the models running on h1susey are shown in the second trend plot attached (two hour trend, BIOS change in the middle). The IOP model (Ch 3) does not show any change. SUSETMY (Ch 4) is running 2uS longer (33uS to 35uS). SUSTMSY (Ch 5) is running 1uS longer. SUSETMYPI (Ch 6) is running 1-2uS longer.
All are well within nominal range.
Laser Status:
SysStat is good
Front End Power is 33.8W (should be around 30 W)
HPO Output Power is 154.8W
Front End Watch is GREEN
HPO Watch is GREEN
PMC:
It has been locked 14 days, 1 hr 23 minutes (should be days/weeks)
Reflected power = 16.87Watts
Transmitted power = 57.1Watts
PowerSum = 73.97Watts.
FSS:
It has been locked for 0 days 1 hr and 12 min (should be days/weeks)
TPD[V] = 1.446V (min 0.9V)
ISS:
The diffracted power is around 3.2% (should be 3-5%)
Last saturation event was 0 days 1 hours and 12 minutes ago (should be days/weeks)
Possible Issues:
None
This closes FAMIS7453
I decided to re-do these measurements because the previous aLOG-38213 seemed to have really bad noise associated with the contour plots for ETMY, I think from one of the ALS loops still being active and trying to lock which flashed some extra light onto the HWS periodically and screwed up the images.
Note: It is a bit difficult to adjust PZT2 to a point where we only saw the ETMY reflection (ETMX still works well), so it seems like the values measured by Nutsinee in aLOG-35979 are no longer valid. I also found it difficult to search for the new offsets needed so Sheila suggested changing the green QPD offsets instead while the PZT servo was in-loop to make the measurement more repeatable:
- H1:ALS-Y_IP_ANG_YAW_OFFSET = -750 cnts
- H1:ALS-Y_IP_ANG_PIT_OFFSET = 840 cnts
- H1:ALS-X_IP_ANG_YAW_OFFSET = -1000 cnts
We also turned off the PLL locking so that ALS doesn't try to lock as well.
I've attached the first 180 secs after power up, there seems to be some absorption present but no obvious point absorbers. However, the things to keep in mind are that the ALS-ETM sampling spot size is only about 5 cm in diameter and the overlap with the resonant IR beam is assumed based off the locking process to get up to DC_READOUT and there could be a more precise way to get better overlap between the two beams.
DC_READOUT: 2017-08-29 03:30:00 UTC
NLN: 2017-08-29 03:43:00 UTC
Daniel, Marc
We successfully installed an Anybus Modbus adapter to the Corner 2 Chassis in the CER to prepare for the installation of squeezer.
This morning I completed the weekly PSL FAMIS tasks.
HPO Diode Current Adjustment (FAMIS 8437)
With the ISS turned OFF, I adjusted the operating current of the HPO pump diode boxes. DB1 increased by 0.2A and no change on DB2, DB3, and DB4. The changes are summarized in the below table; I also attached a screenshot of the PSL Beckhoff main screen for future reference.
| Operating Current (A) | ||
| Old | New | |
| DB1 | 49.8 | 50.0 |
| DB2 | 52.7 | 52.7 |
| DB3 | 52.7 | 52.7 |
| DB4 | 52.7 | 52.7 |
I also adjusted the operating temperatures of the DBs; changes summarized in the below table:
| DB1 | DB2 | DB3 | DB4 | |||||
| Old | New | Old | New | Old | New | Old | New | |
| D1 | 28.5 | 28.5 | 20.0 | 19.5 | 21.0 | 21.0 | 23.5 | 23.0 |
| D2 | 28.5 | 28.5 | 19.5 | 19.0 | 25.0 | 25.0 | 21.0 | 20.5 |
| D3 | 28.5 | 28.5 | 20.5 | 20.0 | 25.0 | 25.0 | 22.5 | 22.0 |
| D4 | 28.5 | 28.5 | 18.5 | 18.0 | 22.0 | 22.0 | 21.0 | 20.5 |
| D5 | 28.5 | 28.5 | 18.5 | 18.0 | 26.0 | 26.0 | 23.0 | 22.5 |
| D6 | 28.5 | 28.5 | 19.0 | 18.5 | 20.5 | 20.5 | 23.0 | 22.5 |
| D7 | 28.5 | 28.5 | 19.5 | 19.0 | 21.5 | 21.5 | 23.0 | 22.5 |
The HPO is now outputting 154.9W and the ISS is back ON. This completes FAMIS 8437.
PSL Power Watchdog Reset (FAMIS 3665)
I reset both PSL power watchdogs at 16:43 UTC (9:43 PDT). This completes FAMIS 3665.
Jason O., Thomas V., TJ S.
TCSX chiller tripped at Aug 29 2017 11:21:40 UTC (1188040918 GPS). Flow rate only dropped to ~2.55gpm, this should not trip until 2.0gpm. See attached.
This 2.0gpm limit is set analog via some resistors in the controller. The plan, sometime in the future, is to test this controller and make sure that the resistance is what it is suppose to be, and then fix/replace if necessary.
Thomas and I went out to the LVEA to reset the interlock and it came right back. Verbal briefly complained that it had turned off a few minutes after we got back, but it seems that it just lost lock briefly and the power fell low enough that Verbal caught it. Everything seems okay now.
Yes it sounds like the right plan is to pull that controller and test it. If we can check what voltage/current causes the controller to trip, then we can check that against the flowmeter setting (which should be in current per gallon per minute).
Sheila, TVo
We successfully swapped DARM control to ITMX.
In this configuration the TMX_DRIVE_ALIGN_GAIN = 150 compared to ETMY_DRIVEALIGN_GAIN = 30 is roughly the right actuation strengths, the OL DARM TF is attached and is roughly unchanged.
This swap allows us to do a charge measurement on ETMY which Sheila will post about in a separate aLOG. This did not change the mystery low frequency noise.
Adjusted curtains
The attached plot shows our typical sawtooth behavior in the timing system. The PPS signals compare the 1 PPS signal from our timing system against other GPS units and the atomic clock. All of these comparisons show this sawtooth indicating it is a feature of our timing system. The master GPS unit which feeds our timing system is a Trimble unit. The GPS_A_PPSOFFSET channel is an internal readback which is read through an RS232. It shows ~80ns single second jumps up and down in synchronization with our sawtooth. This might be an indication that the sawtooth originates in the Trimple. The OCXERROR channels shows the 1 PPS comparison between the timing system and the Trimble unit. It is uses as an error signal for the timing master OCXO. Units are ns except for the OCXERROR which is in seconds. The -1450 ns offset is in the atomic clock.
TITLE: 08/28 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC STATE of H1: Commissioning INCOMING OPERATOR: None SHIFT SUMMARY: Jeff K. ran charge measurements. Sheila fixed a bug from the SUS model change that accounted for additional low frequency noise seen yesterday and this morning. LOG: 15:00 UTC Restarted nuc5. 15:04 UTC Restarted video2. IFO stuck at LOCKING_ARMS_GREEN upon arrival, ETMY needed alignment. 15:20 UTC Kyle to end X VEA. 15:29 UTC Lock loss from CARM_ON_TR. 15:31 UTC Restarted video4. 15:42 UTC Lock loss from DRMI_LOCKED. 15:48 UTC Set ISI config to WINDY_NO_BRSX. 15:49 UTC Lock loss from DRMI_ASC_OFFLOAD. 16:00 UTC Kyle back. 16:14 UTC NLN. Additional low frequency noise present. 16:37 UTC Damped PI modes 27 and 28. 17:13 UTC Karen to warehouse and then mid Y. 17:32 UTC Jeff K. tuning MICH feedforward. 17:38 UTC Lock loss. 17:38 UTC Set ISI config back to WINDY. Leaving in DOWN to let Jeff K. run charge measurements. 17:51 UTC Hugh and Jim to HAM6. 17:59 UTC Hugh and Jim back. Hugh to LVEA. TJ to optics lab. Amber leading tour through control room. 18:27 UTC Hugh back. 18:44 UTC Karen leaving mid Y. 18:48 UTC Sheila restarting ITMY model: SUS and ISI WDs tripped. Charge measurements done. 18:53 UTC Daniel to squeezer bay. 18:58 UTC Relocking, DAQ restart. 19:10 UTC Daniel done, TJ done. Starting an initial alignment. 19:34 UTC Phone call: Hanford monthly alert system test. 19:46 UTC Initial alignment done. 20:26 UTC TJ to optics lab. 20:48 UTC Lock loss. 21:19 UTC Bubba and visitor to LVEA. 21:20 UTC Jeff B. to end stations and mechanical room (not VEAs) to check dust monitor pumps. 21:25 UTC NLN. Jeff K. starting BSC ISI charge measurements. 21:28 UTC Bubba back. 21:36 UTC Jeff K. done charge measurements. 21:40 UTC Bubba to H2 electronics building. 21:57 UTC Mike and Fred taking visitor into LVEA. 21:59 UTC Corey taking visitor to overpass. 22:08 UTC Jeff B. done. 22:17 UTC Lock loss (Jeff K. driving HAMS), HAM2 ISI, IM1, IM2, IM3 tripped. 22:45 UTC Mike, Fred and visitor back. 22:53 UTC Timing system error, SYS-TIMING_X_PPS_A_ERROR_FLAG: error code briefly at 1024 (PPS 1 OOR)
The following units have been balance calibrated as per LIGO-T1600116-v1:
#132740069233007, #132740069233002 and 132140069233006
The unit ending in 007 had been currently in use on the optic in the LSB Bonding lab and was found to be out of spec as defined in the procedure listed above. I was able to adjust it into an acceptable balance as per procedure.
#132740069233004 failed to meet the tolerances as stated in the above procedure.
There is another unit in the Bonding Lab garbing area that has no regulator. I didn't get the number off that one
The data for these units may be found here
On friday Thomas and I ran excitations on all 4 ESDs in order to measure the 4 coefficients in this equation for the force applied by the ESDs (G1600699) Equation 2:
F = α (V_b-V_s)2 +β (V_b+V_s)+ β _2(V_b-V_s)+γ (V_b+V_s)2
The first 2 excitations for each suspension were on the bias path with no signal voltage so that the linear response is:
F = [β+β_2+2(α+γ)V_b] δV_b
The bias path was excited twice, first with the normal bias of 380 V on and second with no bias. Then the script excited the signal path which gives a linear response of:
F = [β-β_2+2(α+γ)V_b+2(α-γ)V_s] δV_s
This path is excited 3 times, once with no DC offset on any electrodes, once with an offset of 7.6Volts on the signal electrodes, and once with the bias at its normal value of 380V.
The first 4 of these measurements allow us to make a complete measurement of all four coefficents, α, β β_2, and γ The fifth measurement is redundant and could be skipped, I used it as a sanity check. I am still worried that I have some signs wrong which are making these results confusing.
| ETMX | ETMY | ITMX | ITMY | |
| α (N/V^2) | 2.1e-10 | 2.0e-10 | 8e-11 | 5.5e-11 |
| β(N/V) | -9.9e-10 | 2.0e-8 | 1.0e-8 | 5.6e-9 |
| β_2 (N/V) | 2.8e-9 | 3.2e-8 | -4.2e-9 | -8.5e-9 |
| γ | 1.5e-10 | 1.2e-10 | -4.0e-11 | -1.2e-11 |
| V_eff = (beta-Beta2)/(2*(alpha-gamma)) | -31 V | -75 V | 60 V | 105 V |
All of the scripts needed for taking the measurement and getting the coefficents are in userppas/sus/common/quad/scripts/InLockChargeMeasurements/
The table above is wrong because of multiple minus signs (which are different between the ITM and ETM ESD drivers) being wrong. Here is a corrected table:
| ETMX | ETMY | ITMX | ITMY | |
| α (N/V^2) | 9.6e-11 | 8.7e-11 | 4.9e-11 | 5.8e-11 |
| β(N/V) | -1e-9 | 2e-8 | -1e-8 | -5.6e-9 |
| β_2 (N/V) | 2.8e-9 | 3.2e-8 | 4.2e-9 | 8.5e-9 |
| γ | 2.6e-10 | 2.3e-10 | -9.2e-12 | -1.5e-11 |
| V_eff = (beta-Beta2)/(2*(alpha-gamma)) | 12 | 38 | -124 | -97 |
The values in this table still had some calibration errors. New log coming soon.
I have compiled the results of in-air measurements during installation and in-vacuum measurements from the alogs; 14231 LLO (including corrections mentioned in alogs 21652 and 27901) and 17610 at LHO (including corrections mentioned on the comments).
In the case when a frequency split is shown on in-vacuum measurements we have taken the average of both frequencies. I have grouped these numbers per front and back fibres, then per test mass and then per detector, finally I obtained the difference as (in-vacuum – in-air) including the sign:
We notice that in most cases the frequency difference is always positive, so frequency increases when moving the suspension to in-vacuum.
The increase in frequency is always a few hundred mHz (mean of 0.3Hz and median of 0.4Hz), with a clear outlier on LLO_ITMY_FL (which as explained here seems to be involved with uncertainty in the identification).
There is not clear difference in frequency variation between front and back fibres (especially no sign difference) which would indicate pitch effect.
However, notice that as per the Technical document T1700399 the expected increase in frequency due to buoyancy is of 0.14Hz, and the variation in frequency due to pitch angles of 2mHz is of 0.33Hz (although that would be an opposite sign change between front and back fibres). Therefore while the observed changes cannot be explained through pitch and buoyancy alone, they are of the same order.
Further discussions on the results presented here has led to realize that the in-air measurements of the violin modes fundamental frequencies have a potential error of about 0.25Hz (as an example here are measurement results for LHO ITMX suspension). In base of this and to better understand the actual differences between in-air and in-vacuum measurements, now that we have very accurate measurements in-vacuum, it would be informative to measure in-air values once the suspensions are taken out.
The in-air measurements have so far been done by acoustically driving the violin mode resonances. During this measurements the frequency of the driving acoustic signal is changed as a sweep sine. Because the in-air Q of the violin modes is considerably less than the in-vacuum values of 1 billion, if the sweep sine drive is not done with suitable slow pace then the observed a violin mode excitation at a frequency on the sweep sine which actually correspond to a previous frequency of the sweep but took some time to ring up. Under this assumption, if the sweep sines were driven down (from high frequencies to lower frequencies) then there would be a consistent error on the measured in-air frequencies with values being lower than in-vacuum ones.
A way to improve the acoustic excitation could be by building a tower of speakers so that they could inject more energy into the violin modes of the fibres. Also be sure to drive the sweep sine at enough low pace or inject random noise excitation instead. Finally a lot of information could be gained by in-air measurements of higher order harmonics, this would help on characterization and understanding of higher order inharmonicity as well as higher order mode identification.
In order to proceed with the in-air measurements of the violin mode and its harmonics during the installation of the suspensions in the near future (as well as measuring the already install suspensions once removed), we have built in Glasgow a line array of 24 speakers of 60 cm length to match the length of the fused silica fibres. Its lightweight and compact design make it suitable to locate it parallel and in close proximity to the fibre that wants to be excited.
This line array produces considerable sound from 300Hz and well above several kHz making it suitable to excite the fundamental mode and up to the 6th harmonic and beyond.
A more complete description can be found on the technical document T1700414T1700414.
It is relevant to this alog to remember that while preliminary FEA modelling of the actual fibre profiles measured during installation of the LHO ITMX suspension (end of March 2014), has been used to predict in general terms the observed departure of the frequencies of the violin mode harmonics from whole multiples of the fundamental (“inharmonicity”):
However this preliminary results show that this prediction is not yet accurate to the few Hz level required for identification:
In order to complete the list of possible causes for the different inair and invacuum measured violin mode frequencies, I add next the contributions suggested recently by Norna, Dennis and Jon Feicht:
Violin modes frequency variations due to air damping
Air damping lowers the in-air measured violin mode frequency by a value inverse proportional to the violin mode’s Q-factor. Such that the maximum frequency for a damped oscillator (fm) is related to the undamped maximum frequency (f0) by:
fm = f0 ∙ sqrt[1-1/(2∙Q2)]
A quick look at recent in-air measurement on the LHO alog 38743 suggest a Q of at least 100 in-air at the ~ 500 Hz fundamental mode. This would give a in-air measured frequency value of the fundamental of 0.012Hz lower than in-vacuum.
Violin modes frequency variations due to mass/length of the fibre decreasing as the water desorbs from the silica fibre in vacuum
The mass loading on the fibre, due to water adsorption in-air, should in principle cause the in-air measurement of the violin mode fundamental frequency to be lower than in-vacuum, as once much of the water is pumped off the fibre in vacuum the frequency should increase. Dennis Coyne calculated that about ~3500 monolayers of water (each 2.5 angstroms thick) would be necessary to cause a 1 Hz shift at 500 Hz, due to mass loading alone. It is commonly asserted in vacuum literature that stainless-steel surfaces of a vacuum system exposed to air can start with "hundreds of monolayers of water".
However fused silica is hydrophilic and the interaction of silica surfaces and water is complex; Surfaces of silica under water can swell and form layers of silica gel1. The modification of the fused silica surface by the chemisorption and physisorption of water may even lead to a reduction in the elastic modulus of the fused silica in the outer layers.
References
[1] V.V. Yaminsky, et. al., "Interaction between Surfaces of Fused Silica in Water", Langmuir 1998, 14, 3223-3235.
When TJ and I went out to check on the chillers around mid-morning, I added an additional 750 mL of water to the chiller. This was added due to an air bubble under the mesh screen filter giving an incorrect reading of the chiller fill level; I released this bubble and then filled with water to the mark Jeff had filled to earlier in the morning.