Tonight I followed up on the work that Stefan & I started two weeks ago, and switched the power-up step in the Guardian to come after the transition to DC readout.
Now, the OMC is locked at 2.3W input power, DARM offset = 3.7e-5 counts / 52 pm. These settings were chosen to provide 20mA at the DCPD Sum. At the transition to DC readout, the overall OMC-READOUT_ERR_GAIN is set to match the DARM gain on AS_Q, and the power normalization is absorbed by the OMC-READOUT_PREF_OFFSET, as Stefan described in the earlier entry.
During the INCREASE_POWER step the DARM offset (which after the handoff is set via OMC-READOUT_X0_OFFSET, in picometers) is stepped down to maintain the same photocurrent out of the DCPDs. This *should* maintain the DARM gain through the quadratic scaling of DCPD Sum as a function of DARM offset...but it's not perfect. I tried this twice today, and after the power-up finished, the DARM loop gain was too low by 30%. Not sure if this is due to the initial gain matching before the handoff (this step still needs some work, maybe a tdssine measurement would be better), or some non-quadratic change in the response as we go from ~50pm to 16pm. Stefan, Keita and I observed a small static fringe offset, we should make a careful measurement of DCPDSum vs DARM offset to check that what we think is quadratic really is.
We believe this arrangement is an improvement, because locking the OMC and transitioning to DC readout is more robust at low power, and also I suspect the power-up is more stable on DC readout. I have increased the PSL waveplate velocity during the power-up (now it's 20, it was 10, not sure about the units), this worked without any trouble. I am leaving the IFO locked at 23W in the LSC_FF state, with the intent bit set to "Undisturbed." The range says 65Mpc - could it be true? Earlier tonight there was a slow angular drift that killed a 23W lock, I am not sure how long we will last. Also the ITMX oplev loop is ringing for quite some time after each lockloss, it may be a challenge for the IFO to relock on its own.
A screenshot of the new guardian sequence is attached. I committed the ISC_LOCK.py code before and after the change. I tested the new sequence twice without a hitch.
ITM oplev damping is now automated in the guardian. The down state turns the damping off. The LOCKING_ARMS_GREEN state turns it back on.
Kiwamu, Jeff, Dan, Cheryl, Eric We successfully tested the transient injection code tinj at LHO for the first time. This is also the first test of tinj since we added interaction with EPICS channels and migrated to svn. An earlier version had been previously demonstrated at LLO. The tests were carried out between GPS = 1117004777 - 1117006270. We scheduled the standard BNS injection (1.4 on 1.4 msun with optimal orientation at 45 Mpc) that has been used in previous tests [1]. This file, which lives in svn, is called injection_H1.out. The goal of the test was to inject this waveform with increasing loudness until the folks at LHO could see the signal sweeping across the strain spectrum. The first attempt failed to inject because H1:CAL-INJ_TINJ_ENABLE = 0. We set the value to 1. The next several attempts (GPS = 1117004777, 1117004993, 1117005152) failed to show up because the transient gain in the CAL model was set to zero. We set it to one and started over. The following injections were successful: 1117005396 2 1 injection_ 1117005598 2 4 injection_ 1117005756 2 10 injection_ 1117005914 2 100 injection_ 1117006170 2 100 injection_ The first column is GPS time, the second is injection type (2 = CBC), the third is scale factor, and the last column is the prefix for the injection file. Dan and Kiwamu weren't 100% sure they were seeing the BNS signal until we injected with a scale factor of 100. During the last injection, (scale factor = 100), Jeff and Eric watched the output of HWINJ filter bank. At the very end, it reached a value of ~50 counts, which did not exceed the current HWINJ LIMIT = 200. We fixed a bug with tinj. First, we fixed a bug, in which the value of TINJ_PAUSE was interpreted incorrectly (1 should have been 0). Also, the binary executable for tinj included in svn yielded a library error: tinj: error while loading shared libraries: libmwlaunchermain.so: cannot open shared object file: No such file or directory So, we recompiled a version that works at LHO and recommitted to svn. NOTE: we have left tinj running in the background for a stability test. However, there are no planned injections currently scheduled. [1] https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=17073
I've attached spectrograms of the five injections. The injections at 1117005598, 1117005756, 1117005914, and 1117006170 show up visibly in spectrograms of L1:CAL-DELTAL_EXTERNAL_DQ. The segment database uses the name H1:ODC-INJECTION_CBC to flag CBC injections. I do not see the injections in the segment database. The following command was used: ligolw_segment_query_dqsegdb --query-segments --segment-url https://dqsegdb5.phy.syr.edu --gps-start-time 1117005296 --gps-end-time 1117006270 --include-segments H1:ODC-INJECTION_CBC
Small correction to something in the original post: note that injection type (TINJ_TYPE) 2 is actually Burst, not CBC, according to https://wiki.ligo.org/Calibration/HWInjBookkeeping and as used in CAL-INJ_ODC on https://wiki.ligo.org/DetChar/DataQuality/AligoFlags. However, that is NOT the reason that there are no corresponding segments in the database. See next comment.
If everything is working properly, hardware injections of transient signals should be indicated by bits in H1:CAL-INJ_ODC_CHANNEL_OUT_DQ (256 Hz, in raw frames), H1:ODC-MASTER_CHANNEL_OUT_DQ (16384 Hz, in raw, rds, and hoft frames), and H1:GDS-CALIB_STATE_VECTOR (16 Hz, in hoft frames only). I checked this using a program called FrBitmaskTransitions that I wrote for this purpose. (It's a handy program and everyone is welcome to use it. It's currently living in ~pshawhan/hwinj/monitor/ on the Caltech cluster.) H1:CAL-INJ_ODC_CHANNEL_OUT_DQ is the most fundamental since that bitmask channel is created in the CAL model. Here's the report for that channel:pshawhan@> ./FrBitmaskTransitions -c H1:CAL-INJ_ODC_CHANNEL_OUT_DQ /archive/frames/ER7/raw/H1/H-H1_R-11170/H-H1_R-111700[56]*.gwf 1117005056.000000 0x30001f87 Data starts 1117005139.625000 0x20001f87 28 off 1117005139.628906 0x30001f87 28 on 1117005139.644531 0x20001f87 28 off 1117005139.648437 0x30001f87 28 on 1117005139.667968 0x20001f87 28 off 1117005139.671875 0x30001f87 28 on 1117005139.738281 0x20001f87 28 off 1117005139.742187 0x30001f87 28 on 1117005139.992187 0x20001f87 28 off 1117005140.000000 0x30001f87 28 on 1117005331.496093 0x30001f82 0 off, 2 off 1117005396.007812 0x30001faa 3 on, 5 on 1117005484.734375 0x30001f82 3 off, 5 off 1117005598.007812 0x30001faa 3 on, 5 on 1117005638.519531 0x20001faa 28 off 1117005638.523437 0x30001faa 28 on 1117005638.800781 0x20001faa 28 off 1117005638.804687 0x30001faa 28 on 1117005639.468750 0x20001faa 28 off 1117005639.472656 0x30001faa 28 on 1117005639.500000 0x20001faa 28 off 1117005639.503906 0x30001faa 28 on 1117005639.519531 0x20001faa 28 off 1117005639.523437 0x30001faa 28 on 1117005641.589843 0x20001faa 28 off 1117005641.593750 0x30001faa 28 on 1117005641.976562 0x20001faa 28 off 1117005641.980468 0x30001faa 28 on 1117005686.734375 0x30001f82 3 off, 5 off 1117005733.746093 0x30000b82 10 off, 12 off 1117005734.496093 0x30001f82 10 on, 12 on 1117005756.007812 0x30001faa 3 on, 5 on 1117005844.734375 0x30001f82 3 off, 5 off 1117005914.007812 0x30001faa 3 on, 5 on 1117006002.734375 0x30001f82 3 off, 5 off 1117006170.007812 0x30001faa 3 on, 5 on 1117006258.734375 0x30001f82 3 off, 5 off 1117007040.000000 0x30001f82 Data endsYou can see that bits 3 and 5 go on and off when they should, corresponding to the five successful injections noted above. (Bit 5 is the bit in CAL-INJ_ODC for type 2 transient injections.) The CW injections were running continuously, except that I see that someone apparently turned off the HARDWARE ACTIVE switch momentarily (bit 10), causing the "HARDWARE non-zero" bit (bit 12) to go off at the same time. I don't know what bits 28 and 29 represent in this bitmask (they aren't in the table at https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=17990), or why bit 28 flickered on and off at times. I also don't know why bits 0 and 2 went OFF at GPS 1117005331.496093; the original post said that the transient gain was initially zero and then they switched it to 1, but if that's the cause then it seems like the meaning of bit 2 is opposite from what was intended (?). The summary bit (bit 0) is probably just following that. Now, combinations of bits from CAL-INJ_ODC are supposed to be represented by summary bits in ODC-MASTER, but I find that they were NOT set:pshawhan@> ./FrBitmaskTransitions -c H1:ODC-MASTER_CHANNEL_OUT_DQ /archive/frames/ER7/raw/H1/H-H1_R-11170/H-H1_R-111700[56]*.gwf 1117005056.000000 0x90bff0d8 Data starts 1117007040.000000 0x90bff0d8 Data endsThe summary bit calculation probably requires bit 0 and/or 2 of CAL-INJ_ODC to be on. And the injection bits weren't set in CALIB_STATE_VECTOR either, but that's not surprising since those are derived from ODC-MASTER:pshawhan@> ./FrBitmaskTransitions -c H1:GDS-CALIB_STATE_VECTOR /archive/frames/ER7/hoft/H1/H-H1_HOFT_C00-11170/H-H1_HOFT_C00-1117003776-4096.gwf 1117003776.000000 0x00000008 Data starts 1117007750.375000 0x0000001d 0 on, 2 on, 4 on 1117007750.437500 0x00000008 0 off, 2 off, 4 off 1117007872.000000 0x00000008 Data endsIt's curious that bits 4 (FILTERS_OK), 2 (SCIENCE_QUALITY), and therefore also bit 0 (HOFT_OK) flashed on for just a brief moment during the 4096-second interval I scanned, but that's unrelated to the hardware injection tests. Finally, no segments were inserted into the segment database, but that makes sense because bit 2 in CAL-INJ_ODC was off (for some reason -- maybe a bug) and I believe that is required to be on in the SegGener configuration.
Jeff, Kiwamu,
This is a summary of the calibration of the ETMY suspension responses (in meters/counts) using the ALS diff VCO.
I have not evaluated systematic errors. The errors in this summary includes only statistical errors. The "models" I mean in this alog are the ones generated by the generate_QUAD_Model_Production matlab function in the suspension SVN. The model uses the "nominal" ESD force coefficient of 2e-10 [N/V^2]. The below is a summary of the results.
- - -
ETMY ESD is weaker than the model by 0.4242 +/- 0.0030
ETMY L2 is stronger than the model by 1.0344 +/- 0.0074
ETMY L1 is stronger than the model by 1.0269 +/- 0.0083
ETMX ESD is stronger than the model by 1.187 +/- 0.012
- - -
As for the ESDs, in terms of the force coefficient, they can be translated as
ETMY ESD force coeff. = 8.484 e-11 +/- 6.0e-13 [N/V^2]
ETMX ESD force coeff. = 2.374e-10 +/- 2.3e-12 [N/V^2]
[ETMY suspension responses]
I start from the results. See the attached two plots shown right below:
The first plot is a comparison of the measured response of all three stages with the models in units of [m/cnts]. Here "cnts" refers to the digital counts at the output of the ETMY_L1(2, 3)_LOCK_L filter bank. The second plot shows the ratio between the measured and modeled transfer functions. They are ratio of (measured) / (model). As you can see, the L1 and L2 stages agree with the model qualitatively. On the other hand, it is very clear that the ESD of ETMY is much weaker than what model predicts by a factor of 0.42. We don't know why this is so weak, but this is consistent with what the MICH free swing test says (see Jeff's alog for more details). Also, the L2 stage showed a phase lag of roughly 10 degrees. We don't know why at this point.
The steps for getting these results are something like the follows.
If the ETMY ESD was stronger and as strong as that of ETMX, the steps in full lock are unncessary because we could measure it in the ALS diff configuration. However as we learned (see alog 18656), the low-voltage ETMY ESD needs a low-noise configuration. Note that the measured responses in full lock are also used in Jeff's analysis which had started from free-swing MICH fringes. Also, from the point of view of data points, we probably can go up to about 20 Hz at which the ALS diff signal is completely covered by some sensor noise. This time the frequency bins are chosen such that we can share them with the MICH calibration technique which was severely limited to frequency below 7 Hz due to high semsor noise in the simple MIchelson configuration.
As for the statistical error analysis, we used:
For comparing the measured responses with the models, we assume that the models and measurements have the same transfer function shapes and therefore the scaling factor is the only parameter we estimate. Though, this assumption may not be true because we see a large differenence in the phase of the L2 stage.
For completeness, I attach all the relavant measured responses:
The ETMY suspension states (for all the measurements):
[ETMX ESD response]
At a different time, we measured the response of the ETMX ESD using a similar technique to the ETMY measurement. The steps went as follows.
Since the ETMX ESD does not use a low-voltage driver, the measurement can be complete only with the ALS diff loop closed. This is a big difference from the ETMY measurement which required low-noise stage for accessing the ETMY ESD.
The two plots shown below are the main results.
As shown in the first plot, overall, the measuement qualitatively agree with the model. The second plot shows the ratio of (measured) / (modeled). The absolute magnitude was larger than what the model predicted by a factor of 1.19. As mentioned earlier, the model uses a force coefficient of 2e-10 [N/V^2]. Unlike the ETMY ESD, the phase deviation (or perhaps I should say phase lag) is a bit larger than that of the ETMY for some unknown reason. The error propragation was done in the same fashion as that of the ETMY measurement (i.e. we included only coherence-based errors and VCO calibration error).
ETMX ESD configuration:
For completeness I post all the relevant transfer functions:
[ALS diff VCO calibration]
On this past Tuesday, Dick and I measured the VCO response. We hooked up an IFR 2023 A which was synchronized to a 10 MHz rf signal (which is synchronized to GPS) to the diff PLL input or the PFD rf input with an amplitude of 0 dBm in order to simulate the beat note signal. Even though we could read out the display of the IFO 2023A, we used an external frequency counter (H1:ALS-C_DIFF_VCO_FREQUENCY) which should be at least as accurate as 5 Hz (see for example alog 6972). We locked the PLL loop and manually swept the frequency of the IFR until the PLL unlocks. The speed of the sweep was roughtly 25 kHz/minutes. Then we recorded the output of the DIFF_PLL_CTRL filter bank. One thing we have to pay attention is that this filter already contaied calibration filters which were meant to calibrate the VCO into microns, but as we measured the calibration factor was wrong by roughly a factor of 3.
The setting for DIFF_PLL_CTRL
In theory FM3 should cancel the pole and zero at 1.4 and 40 Hz respectively in the VCO circuit. The meaured data is shown in the plot right below:
The data was then trancated such that the center frequency is located at 78.92 MHz with a range of +/- 30 kHz for a linear fitting purpose. Also, since we made a linear fitting at around 78.92 MHz, in any of the calibration measurement we tried to be as close as possible to this frequency by engaging the slow frequency couter servo to the ALS diff VCO, According to the fit the coefficient was of VCO -> PLL_CTRL was esimtimated to be 4.78268e-6 +-/ 0.002531e-6 [cnts/ Hz] using a least square fitting of gnuplot. These numbers were used for calibrating the ETM responses and estimating the errors.
Finally I attach a zip file which contains all the data (in ASCII not in xml), analysis codes and figures.
Now, all the relevant codes, data, xml templates and figures are checked in svn with more appropriate and organized names. They can be found in :
aligocalibration/trunk/Runs/PreER7/H1/Scripts/AlsDiff
aligocalibration/trunk/Runs/PreER7/H1/Measurements/AlsDiff
aligocalibration/trunk/Runs/PreER7/H1/Results/AlsDiff
Jeff asked me to turn the actuator responses into meter/counts at DC (techniqcally speaking at 1 mHz). Here are the numbers:
- - -
ETMY L1 = 5.150e-11 +/- 4.1e-13 [m/cnts]
ETMY L2 = 7.007e-13 +/- 5.0e-15 [m / cnts]
ETMY L3 = 6.432e-15 +/- 4.9e-17 [m/ cnts]
ETMX L3 = 3.593e-13 +/- 3.5e-15 [m/cnts]
- commissioning early in the shift
- in and out of DC Readout the last 2 hours
Currently: Eric Thrane making injections right now
IFO locking: DRMI is taking a long time to lock, repeatedly needing alignment
Today we added a few filter modules and True RMS parts to the h1oaf model to allow us to monitor the size of the bounce and roll modes in DARM (alog 18706). One motivation is to allow us to automatically adjust the gains of the damping loops based on the amplitude of the signal in DARM, a second to make it easier to identify which optic is rung up.
The changes to the model were simple; we use the existing IPC that sends DARM control to the deprecated CAL part of the oaf model. There are 10 new filter banks, 2 are used for fairly wide bandpasses to include all the bounce or roll modes, the rest are for a specific mode on a specific optic. I've loaded bandpasses that are 0.04 Hz wide in the single optic filter banks, and I've added gains that make the rms roughly 1 when the modes are damped well enough that they don't show up in the DARM spectrum. I'll look forward to readjusting these gains when the noise gets better.
The medm screen is accessible from the SUS tab.
SudarshanK, RickS
We have reduced the amplitude of the higher frequency Pcal lines by about a factor of five as follows:
Xend 534.7 Hz: 28570 cts. -> 6000 cts.
Yend 540.7 Hz: 23500 cts. -> 5000 cts.
Sheila, Dave:
Sheila made a h1oaf model change [WP5232], this required a DAQ restart which was done at 17:35PDT
The system which runs on cdslogin and sends emails and cell phone text messages if certain vacuum or fmcs EPICS signals go out of nominal was reconfigured and restarted. The changes are:
07:15 Rick to EY for PCal
08:00 Ops phone apparently not ringing
08:16 Sudarshan to EX end assuming Rick went there. Rick reported no one answered at ops. (ringer)
08:20 re-booted FOM video4
08:42 Kingsoft on site
09:10 Rick and Sudarshan to both end stations to do calibrations on Pcal. Will not be moving mirrors.
09:12 P King into LDR
09:15 Peter out of LDR
09:20 Jodi at MidX
09:25 Jodi out of MidX
09:31 Kingsoft off site
09:32 Bubba to begin strip installation on X arm just the other side of the berm
09:50 Richard to EX to check out phones
10:17 Richard back from EX
10:21 Jodi back from MidY.
10:53 Pcal team out of the Ends
11:00 Rick Nutsi and Sudarsh back from End stations
11:02 Pcal team back out to EY
11:05 2 tour groups in succession into the control room
12:30 Rick et al finished at EY
12:35 Begin initial alignment
12:42 Dark Mich locked
12:55 initiated ISC_LOCK
13:16 DC readout. will stay here and asses before proceeding to LSC_FF
14:30 Sigg went to MidY
14:45 Sigg back from MidY
Sometime earlier in the week one of the storms knocked the phones out at End x. I have traced it down to the switch at the corner station. I have reprogrammed a different port to connect to the end station and the phone should now work
Jeff, Evan
The current CW hardware injections into DARM control are too loud to allow transitioning from ETMX to ETMY. So we turned them off around 21:00:00 by turning off the input to CAL-INJ_HARDWARE.
On ETMX, the loudest line (at 1395 Hz) has an rms of about 2 counts. For ETMY (with the low-pass filter on the low-noise driver), one must actuate 50×(50/2.2)2 ≈ 26000 times harder at high frequencies. That means the ESD will have to push 50000+ counts rms. The attached plot shows the DARM drive at a few points along the actuation chain (only ETMX was used as an actuator). The hardware injection does not show up in DARM_OUT, or in the version of DARM_OUT that it sent to the CAL model. It does show up in the ETM drives. The attached screenshot helps us remind ourselves of the relevant model topology.
Also note that this is happening at frequencies above the Nyquist of the quad drive DQ channels, which is currently 1 kHz. That means it would have been much harder to catch this if we had been trying to do a lockloss analysis after the fact. The same goes for instances where the drive is being saturated by higher-order violin harmonics, as has happened in the past.
The line amplitudes were bumped up by a factor of 10 for last night's test. Can we remove that factor of 10 to see if you still see problems? We can go down still further for the higher-frequency lines.
Yes, factor of 10 lower is probably fine. I turned injections back on with a gain of 1 instead of 10.
Here is a recent DARM spectrum, taken with 24.6 Watts of power into the IMC, with the new low noise ESD driver with the low pass on.
The peaks around 300 Hz which are worse than in the reference are coherent with the PSL periscope, we might be able to adjust IMC WFS offsets to improve this. There is also coherence with SRCL, there was no feedforward of MICH or SRCL durring this time.
This lock stretch did not appear on the summary page, this must have to do with the change on the sumary page from H1:DMT-SNSW_EFFECTIVE_RANGE to H1:DMT-SNSH_EFFECTIVE_RANGE. I'm not sure when the SNSH is calculated, but we should note that some good lock stretches are now missing from the summary pages.
I have restarted h1broadcast0 with the latest DMT channel list from John Z. Number of channels was reduced from 1080 to 928 (removed 284, added 132)
https://redoubt.ligo-wa.caltech.edu/websvn/filedetails.php?repname=cds_user_apps&path=%2Ftrunk%2Fcds%2Fh1%2Fdaqfiles%2Fini%2FH1BROADCAST0.ini
Chris B, Jeff, Eric Starting at GPS = 1116915517, we turned on the HWINJ with gain=10 to run in the background indefinitely. The idea is to make the CW signal loud enough that CW can recover some of these signals with just a few days of data, but weak enough so that they don't disturb the strain spectrum significantly. If these jobs are found to cause a problem with anything, simply disable the injections with the off switch in the cal model. NOTE: the overall injection gain is now set to 10, so any tinj injections should be scaled DOWN by 10x. Here are the CW signals that are currently active (frequency and amplitude shown below not including gain=10 factor): -bash-4.1$ grep Freq *cfg Pulsar0_StrainAmp.cfg:Freq = 265.5771052 ## GW frequency at tRef Pulsar1_StrainAmp.cfg:Freq = 849.0832962 ## GW frequency at tRef Pulsar2_StrainAmp.cfg:Freq = 575.163573 ## GW frequency at tRef Pulsar3_StrainAmp.cfg:Freq = 108.8571594 ## GW frequency at tRef Pulsar4_StrainAmp.cfg:Freq = 1403.163331 ## GW frequency at tRef Pulsar5_StrainAmp.cfg:Freq = 52.80832436 ## GW frequency at tRef Pulsar6_StrainAmp.cfg:Freq = 148.7190257 ## GW frequency at tRef Pulsar7_StrainAmp.cfg:Freq = 1220.979581 ## GW frequency at tRef Pulsar8_StrainAmp.cfg:Freq = 194.3083185 ## GW frequency at tRef Pulsar9_StrainAmp.cfg:Freq = 763.8473165 ## GW frequency at tRef Pulsar10_StrainAmp.cfg:Freq = 26.3589129 ## GW frequency at tRef Pulsar11_StrainAmp.cfg:Freq = 31.4248598 ## GW frequency at tRef Pulsar12_StrainAmp.cfg:Freq = 39.7276097 ## GW frequency at tRef -bash-4.1$ grep aPlus *cfg Pulsar0_StrainAmp.cfg:aPlus = 2.0125e-25 ## plus-polarization signal amplitude Pulsar1_StrainAmp.cfg:aPlus = 6.4405e-25 ## plus-polarization signal amplitude Pulsar2_StrainAmp.cfg:aPlus = 3.74175e-24 ## plus-polarization signal amplitude Pulsar3_StrainAmp.cfg:aPlus = 8.1915e-24 ## plus-polarization signal amplitude Pulsar4_StrainAmp.cfg:aPlus = 2.45645e-23 ## plus-polarization signal amplitude Pulsar5_StrainAmp.cfg:aPlus = 2.94475e-24 ## plus-polarization signal amplitude Pulsar6_StrainAmp.cfg:aPlus = 3.54275e-25 ## plus-polarization signal amplitude Pulsar7_StrainAmp.cfg:aPlus = 1.728625e-24 ## plus-polarization signal amplitude Pulsar8_StrainAmp.cfg:aPlus = 7.9815e-24 ## plus-polarization signal amplitude Pulsar9_StrainAmp.cfg:aPlus = 5.6235e-25 ## plus-polarization signal amplitude Pulsar10_StrainAmp.cfg:aPlus = 2.343323e-024 ## plus-polarization signal amplitude Pulsar11_StrainAmp.cfg:aPlus = 9.958896e-024 ## plus-polarization signal amplitude Pulsar12_StrainAmp.cfg:aPlus = 1.331275e-025 ## plus-polarization signal amplitude
One thing to watch out for is that for the sake of continuity with initial LIGO HW injections (cf. Emerson, consistency, hobgoblins), we use reference times going back to the start of S3, and some of the stars are spinning down pretty hard. The parameters for this set of injections, including the ER7 start and stop frequencies in the source rest frames can be found here. (Those frequencies can be further modulated by Doppler effects from the Earth's rotation and orbital motion, but for the duration of the ER7 run, those effects are no greater than 1/100,000.) In particular, the start-of-ER7 source-frame frequencies for the 13 pulsars are the following, where especially large spin-downs are noted: 0 - 265.575587774 Hz 1 - 848.973602759 Hz 2 - 575.163522907 Hz 3 - 108.857159395 Hz 4 - 1393.875953 Hz (vs 1403.163331 Hz in S3) 5 - 52.8083243585 Hz 6 - 146.258236176 Hz (vs 148.7190257 Hz in S3) 7 - 1220.57005882 Hz (vs 1220.979581 Hz in S3) 8 - 191.145490954 Hz (vs 194.3083185 Hz in S3) 9 - 763.847316495 Hz 10 - 26.3430397679 Hz 11 - 31.4247651214 Hz 12 - 38.5604676312 Hz (vs 39.7276097 in S3) I checked the 15 minutes or so of data from last night, preceding the Alaskan earthquake, where all pulsars were turned on. Not all of them were immediately visible, but attached are spectrograms for some that were obviously there (the NDS2 server is giving me trouble at the moment; I'll look for more signals later).
NDS2 is cooperating again. Here are spectrograms for additional visible CW injections in last night's pre-quake lock.
After a measurement of charge on each ETM yesterday, I took a few more on each today. Attached show the results trended with the measurements taken in April and Jan of this year. There appears to be more charge on the ETMs than in previous measurements, although there is quite a spread in the measurements. The ion pumps at the end stations are valved in.
Note, the measurement was saturating on ETMy so Kiwamu pointed me to switch the ETMy HI/LOW Voltage mode and BIO state. This made the measurement run with saturation. Attached is a snapshot of the settings I used for the ETMy charge measurement.
1. I think that the results of charge measurements of ETMY on May, 28 are probably mistaken. I haven't see any correlation in dependence of pitch and yaw from the DC bias. 2. It seems like there was very small response at ETMX LL quadrant at this charge measurements. Other ETMX quadrants are ok. It correlates with results of June, 10 https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=19049
Dan, Evan, Sheila
Tonight we started to look at the angle to length couplings of our test masses. We injected lines into pitch and yaw on the PUMs, and adjusted the A2L gains to minimize them. Using the math in the 40 meter alog and Jax's alog, we can estimate the miscentering from these measurements
Gain P2L | vertical miscentering (mm) | Gain Y2L | horizontal miscentering (mm) | |
ETMX | 1.6 | 21 | 1.1 | 14.4 |
ETMY | 0.69 | 9 | -0.3 | -3.9 |
ITMX | 2.4 | 31.5 | 1.15 | 15 |
ITMY | 1.5 | 19.7 | N/A (-1.7 to -2) |
After we had adjusted these, we saw an improvement in the spectrum below 20 Hz. The line in the attached screen shot at 16.6 Hz with sidebands at half a hertz are the excitation. Keep in mind that this is on the new ESD driver and we haven't redone the calibration yet, but clearly this improved the noise below 20 Hz.
Earlier in the evening we were having difficuulty powering up because of a pitch instability at the main suspension resonant frequency that showed up in all the test masses. We moved the QPD offsets for pitch back to what they were may 15th, (they had been changed last tuesday). We then remeasured the miscentering for pitch only, things were a little bit better. Once we increased the power to 17 Watts, the IFO was stable and we repeated some of the measurements. We were able to power up to 23 Watts without seeing the instability twice, but lost the lock quickly for other reasons.
Gain P2L | vertical miscentering (mm) | 17 Watts P2L | ||
ETMX | 0.7 | 9.18 | 0.8 | |
ETMY | -0.57 | -7.5 | -0.49 | |
ITMX | 2.1 | 27.6 | 2.4 | |
ITMY | 1.2 | 15.7 | NA |
DARM OLTF file attached. This template has reduced drive strength so that the ESD does not saturate in the LVLN state.
At last I was able to switch the DARM actuation over to ETMY at 25 W with the LPF engaged on the LVLN driver. We had discovered that the L1 LOCK filters on the ETMs were charging up because of small amounts of ringing in the lower stage filters. Therefore, the L1 filter for ETMX is zeroed after actuation is moved to ETMY, and the lock filters for ETMY are cleared after lockloss. Also, the INCREASE_POWER state now automatically increases the power to 25 W once again.
I tried the LOWNOISE_ESD_ETMY state at 25 W once, and it seemed to work. I then turned on some pieces of the LSC_FF state (namely the SRCL gain reduction, the SRCL cutoff, and the MICH FF). I am leaving the IFO locked with the intent bit undisturbed.
One last note: the power was 3 Watts in the spectrum attached, and to repeat, the calibration is not updated since the actuator change. They're working on it
The displacements in mm are wrong here, we were measureing from the PUM.
Another DARM OLTF, this time with the ETMY LPF off.
There are two DARM Open Loop Gain TFs attached as comments to this entry that represent the first two DARM OLGTFs taken with the new low noise ESD driver and the new L1L2L3 hierarchical control scheme. I've downloaded them and submitted them to the CalSVN for use later: - From LHO aLOG 18662, DcDarmLVLN.xml, measured starting 2015-05-28 13:17:00 UTC, has been copied to /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Measurements/DARMOLGTFs/2015-05-28_H1_DARM_OLGTF_LHOaLOG18662_ETMYL3LPON.xml - From LHO aLOG 18709, DcDarmLVLN.xml, measured starting 2015-05-30 03:07:00 UTC, has been copied to /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER7/H1/Measurements/DARMOLGTFs/2015-05-30_H1_DARM_OLGTF_LHOaLOG18709_ETMYL3LPOFF.xml. I attach conlogs of all relevant DARM filter banks and BIO switches, where the date in the file name corresponds to each measurement.