This is a report about a small task that has been in Daniel's commissioning calendar for a long time (see for example alog 10451).
I checked the signals of REFL_A and compared them with the in-air ones to check if they are functional.
The signal levels seem reasonable and therefore I conclude that REFL_A is functional without a problem. See below for more details.
Comparison of the signal level:
Before doing anything, I adjusted the demod phase of REFL_A_RF45 which had not been set to a useful number. It is now set to be 5 deg. This maximized the PRY signal in the in-phase output. On the other hand, REFL_A_RF9 seemed already good and therefore I didn't change the demod phase. Then I locked the PRY and injected a 10 Hz excitation in order to compare the responses between the in-vac and in-air ones using dtt. Note that I only used the in-phase signals as the q-phases don't really give a good signal in this situation. At the same time, the DC power on the PDs were measured to be 14200 cnts and 8020 cnts at REFL and REFLAIR respectively. This means that the in-vac one should show a higher response by a factor of 1.77 due to the difference in the power falling on the diodes.
Unfortunately, I wasn't able to figure our whether S1300533 or S1300534 is in HAM1. So for now I use transimpedance gain of 600 and 730 Ohms for 9 MHz and 45 MHz respectively which should give us a coarse estimation of the signal levels.
Expected and measured ratios of the 9 MHz detectors:
Expected and measured ratios of the 45 MHz detectors:
Thomas Vo, Greg Grabeel After hearing that LLO had an alignment problem with SM1 and SM2 Thomas and I decided to look and see if we could get a visual confirmation on alignment. Taking the opportunity given by a soft valve close, we stuck a camera up to the viewports and took some pictures. One set of pictures is through the regular glass, and the other are through the Zinc Selenide. The pictures are a little blurry from the long exposure time needed to get anything to stand out, but it looks like we are still good for having the test masses in sight.
800 - Karen to EY
904 - Fil and Aaron at EY most of the day workign on cabling
930 - Betsy,Kate,Margot working EY
940 - Arnaud meas ETMX
945 - Kyle Soft close GV7
945 - Kiwamu and Yuta re-aligning ISC Table at HAM2
1301 - HFD onsite
1310 - Corey and Hugh to ETMY with IAS
Yuta and Kiwamu,
Since we changed the input pointing during the weekend (see alog 10637), we wanted to make sure that the alignment is still OK on ISCT1.
The beam was found to be off in both horizontally vertically by 5 mm or so everywhere in the REFL path. So we took this opportunity to realign everything, including the REFL and POP paths. Now the beam is all centered except for the top periscope mirrors which we can not easily see the surface.
After the realignment, we confirmed that the PRMI still locks.
Jeff, Sheila
Last night when Jeff brought the ISIs back after trips due to the first earthquake, he reset the target offsets as we have discussed doing from now on. This moved ETMX ISI RZ (yaw) by 16urad on stage 1, 12 urad on stage 2, RY (pit for TMS) by 3 urad on stage 1, and 2 urad on stage 2. This is at least the third time that we have reset the target values for ETMX, and the second time we have seen a large move. (25 urad seen in RZ in alogs 10596 10602)
If we had changes of less than a urad, either our dither alingment or WFS would be able to correct for that, if we had changes of less than about 5 urad we would still be able to find the baffle PDs easily to recover the alignment. 20 urad though is difficult to recover from. I (Sheila) would prefer waiting for T240s to settle than doing a random walk in alignment over 10s of urad.
We had a look at the other optics, and they don't seem to move that much. ITMX for example had no changes larger than 100nrad last night.
It seems like the solution proposed by Brian of keeping RZ and RY for the ETMs would solve this, but here is a plot to show what is going on.
We did a model restart of all the BSC-ISIs last Tuesday. By doing that, we restored the old target values stored into the snap files.
On ETMX, these old target values were huge compare to the natural position of the ISI. That explains why, when we reset the targets yesterday after the earthquake, the new location of the ISI is so different than last week.
If you compare the location of the ISI now with the location BEFORE the model restart, you can see that the difference is way smaller (a little big on RZ and Z though).
Here is the list of commissioning task for the next 7-14 days:
Green team:
Red team:
Blue team (ALS WFS):
Blue team (ISCTEY):
TMS:
SEI/SUS team:
Yesterday on Sunday, Mitchell and I got 6 of the 8 HEPI Actuators attached. The remaining corner (NE#4) should fall by late morning Monday along with any alignment adjustment obvious from the Dial Indicators. So far the DIs are looking pretty good as to alignment. If IAS has its instruments at the ready, we should be complete by mid-day with post actuator install check/adjustments.
The ISI has a C3 cover on it so is not fit for TFs. SUS and TMS should however feel free to do evaluate their systems.
I found that the most of the ISIs had been tripped. Probably it was due to the earthquake as logged by Jeff (alog 10638).
I untripped the following systems:
Currently I am having a trouble in engaging the Tcrappy blend filter on stage 2 of ITMX. I am leaving it with the simplest filter, i.e. "Start", for now.
And also IM3.
I had recovered the ISIs after the Earthquake I logged. There was another earthquake, 6.8 off the coast of california (see USGS Page) at 2014-03-10 05:18:13 UTC (5 hours later) that killed everything.
Assuming the frequency calibration of the network analyzer is accurate, we can compare the measured PRC length with the measured mode cleaner length. This was measured in alog 9679.
Parameter | Value | Unit |
---|---|---|
FSRPRC | 2.600075 | MHz |
LPRC | 57.6508 | m |
FSRMC | 9.099173 | MHz |
LMC | 16.473612 | m |
FSRMC / 3.5 - FSRPRC | -306 | Hz |
(1 - FSRMC / 3.5 FSRPRC) LPRC | 6.8 | mm |
Compared with the modeclaner, the power recycling cavity is about 7 mm too short. The other way around, the modecleaner is about 2 mm too long.
We hooked up the network analyzer to the timing comparator/frequency counter and set it to 40 MHz sharp at 0 dBm. The readback value was dead on, occasionally we would read 1 Hz higher. Conclusion: the frequency of the sweep is no more than 1 Hz off, even at 100 MHz.
I've redone the fits using both the magnitude and the phase. The fitting function is now the usual Fabry–Pérot reflectance function, with a complex magnitude to allow for global amplitude rescaling and global phase offset.
Nominal FSR | Frequency (Hz) |
−39.5 | −102 701 040 ± 200 |
−39.5 | −102 700 900 ± 220 |
−26.5 | −68 900 600 ± 180 |
−12.5 | −32 500 080 ± 100 |
12.5 | 32 501 720 ± 110 |
26.5 | 68 903 940 ± 200 |
39.5 | 102 704 700 ± 200 |
The linear fit now gives an FSR of (2 600 073 ± 9) Hz. This is consistent with the previous fit, and anyway the total error is still dominated by some systematic, as seen by the fact that the residuals are excessively large.
Taking a systematic 400 Hz uncertainty on the residual for the 12.5 FSR measurement gives a systematic uncertainty of 32 Hz on the PRC FSR. Propagating foward gives (57.6508 ± 0.0007) m.
J. Kissel As of 2014-03-10 03:00 UTC (08:00p PT), I've left the functional BSC-ISIs in the following state: ITMY BS ITMX ETMX Iso Blend | Iso Blend | Iso Blend | Iso Blend | HPI Lvl 1 "Pos" | Lvl 1 "Pos" | Lvl 1 "Pos" | Lvl 1 "Pos" | ST1 Lvl 3 "TCrappy" | Lvl 2* "TCrappy" | Lvl 3 "TCrappy" | Lvl 3 "TCrappy" | ST2 OFF | OFF | OFF | OFF I left ST2 OFF, because I want to get a measure for the differences between chamber performance is as related to the differing input motion at low frequency. Unfortunately, the ISI BS's level 3 controller appears to be unstable, so I had to stick with Level 2, but this shouldn't matter for the regions I'm looking to study. I've also made sure all optical levers are aligned.
J. Kissel I've grabbed spectra from all possible degrees of freedom of the ground, HEPI pier, and ISI ST1 for the four operational ground sensors and the four operational BSC-ISIs during a very windy and noisy afternoon this past Thursday, Mar 6 2014 at 22:15 UTC. This will hopefully assist modelling efforts to design blend filters that might be able to withstand such input noise. Unfortunately, because Sebastien was commissioning a few chambers, and we had to reboot ETMX to get his GND T240 stored in the right place, there wasn't any long stretch of time during that day in which all platforms were at comparable performance (hence the differences in the ISI ST1 performance). Also, I'm not sure I believe what the rotational HEPI L4Cs are saying at the microseism. The spectra are attached, but they were created by the following DTT templates, /ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/Common/Data/ 2014-03-06_2215UTC_GroundMotion_ASDs.xml 2014-03-06_2215UTC_HEPIPierMotion_ASDs.xml 2014-03-06_2215UTC_ISIST1Motion_ASDs.xml and they were also exported to the following files /ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/Common/Data/ 2014-03-06_2215UTC_Windy_GroundMotion_ASDs_ITMY-XYZ_HAM2-XYZ_HAM5-XYZ_ETMX-XYZ.txt 2014-03-06_2215UTC_Windy_ISIST1Motion_ASDs_BS-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_ISIST1Motion_ASDs_ETMX-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_ISIST1Motion_ASDs_ITMX-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_ISIST1Motion_ASDs_ITMY-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_PierMotion_ASDs_BS-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_PierMotion_ASDs_ETMX-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_PierMotion_ASDs_ITMX-XYZRXRYRZ.txt 2014-03-06_2215UTC_Windy_PierMotion_ASDs_ITMY-XYZRXRYRZ.txt where the last part of the file name indicates the order in which the channels have been exported.
Yuta, Sheila, Alexa
Today we found an alignment that should be acceptable to both PRMI and the Xarm, in the hopes that the green team and red team will not each have to change PR2 significantly each day.
First Yuta aligned PRX, then we aligned the Xarm, locked the IR to the X arm, and moved PR2 and IM4 to point the beam down the xarm. After this the alignment of PRX was way off and unlockable. We checked that the beam was centered on POPAir B, then restored PR2 to the intial PRX alignment. Then Yuta aligned PRM by hand, and walked PR2 back to the arm alignment. Finally Yuta realinged PRY. A screenshot of the final positions is attached.
Yuta has changed the dither guardian script for PRX so that the PR2 dither is now fed back to PRM instead of PR2.
Hopefully this means that the PRMI and arm alignments will stay compatable and both the red team and green team don't have to spend as much time aligning each day.
Just an observation from this morning:
I wanted to see how much power build up the PRC can achieve without touching the alignment. I reverted PRM, BS and ITMY to the values that Sheila had in her screen shot because their alignment wasn't saved and they had come back to some past values by the guardian. The highest build up I saw was about 12 uW in POPAIR_B_RF18 which is about 6-7 times smaller than the highest in the past. Not bad.
Note that ITMX, ETMX and TMXS had different alignment biases than that in the screen shot. I assumed that there had been a fine touch by the green team and I didn't revert them to the screen shot values. The green light mostly stays on a 01 mode and occasionally on a 00 mode.
Yesterday night and this morning some diagonalization measurements were taken with pum drive on etmx and itmx. The low coherence for the pitch drive described on the previous alog was due to the optic not centered enough on the oplev, so both ETMX p2p and y2y were remeasured. Those measurements can actually be really fast (15/20min each).
ITMX measurement has some calibration factor of 1.56 for Yaw and 1.83 in Pitch. T1100378 was the reference for calibrating the drive from cts to N.
Attached are the plots comparing the measurement and the model (wirerehang for itmx, fiber for etmx). Note that there is a sign error in ETMX Yaw, so we should double check if that comes from the Oplev sign convention.
ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Results/quad_{p2p/y2y}.mat
ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Results/quad_{p2p/y2y.mat
ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-06_H1SUSITMX_{P2PY/Y2PY}_WhiteNoise.xml
ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-04_H1SUSETMX_{P2PY/Y2PY}_WhiteNoise.xml
ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Scripts/itmx_L2_diag.m
ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Scripts/etmx_L2_diag.m
PUM drivealign P2P and Y2Y filters were installed.
In each of the attached, foton screen shot to the left shows the actual filter installed, matlab plot to the right shows the P2P or Y2Y measurement, fit, model, and the expected TF from PUM to the test mass after the new filter takes effect.
As you see I made the filters such that ITM and ETM looks as if they share the same low Q (Q=3) resonance at 0.51 Hz for PIT and 0.6Hz for YAW. There's also a roll of at 30Hz, which is not that aggressive. If necessary you can easily add more.
I ignored the DC calibration of the measurement. I'll handle them in the gain.
The filters relevant are FM1 of H1:SUS-ETMX_L2_DRIVEALIGN_P2P, Y2Y and corresponding ITMX filters.
Scripts used for the fit and inversion as well as the filter definition files generated by the scripts are:
~controls/keita.kawabe/fit/[EI]XPUM_[PY]2[PY]fit.m
~controls/keita.kawabe/fit/[EI]XPUM_[PY]2[PY]inversion_soscoeffs.txt
[Yuta Keita Arnaud]
ETMX ITMY ITMX top mass P2P drivealign filters installed
On friday, filters were designed the same way as Keita, in order to get a single pendulum transfer function from the top mass drive to the test mass displacement in pitch. The filters were installed in the top drivealign matrix in FM1 of the P2P bank filter. ITMX filter is a copy paste from ITMY, assuming they have the same P2P transfer function (both are wires). Attached are the plots showing the design of the filters and the foton version. The transfer function after filtering has its cut off frequency at 0.45Hz for ETMX and 0.55Hz for ITMY/ITMX.
ETMX Length to pitch decoupling was also designed and installed in L2P drivealign matrix. Plots of design pending.