The BS optical lever has been realigned with HEPI unlocked (and untripped), ISI damped and SUS damped. This is also with a verbal OK from ISC saying that the current alignment of the optic is good.
The h1iscey front-end computer lost contact with the I/O chassis Monday evening, it's unknown why. Tuesday morning I disconnected the computer from the dolphin network, then powered off computer. On power up, the I/O chassis connected OK, and the models started. Note that the H1PEMEY model has a 0x2000 DAQ status, indicating that most likely the H1PEMEY.ini file has changed. The 0x2000 status will require a DAQ restart to clear.
Emily, Tristan, Terra, Thomas ITMY optical lever has been showing lots of drift in yaw for the past few weeks (~ 1 urad/1 min), today we were able to close the gate valves and shutter the PSL so that we can open the transmitter and receiver units. At first we thought a few screws were loose and they were tightened, but that didn't help. Then we strain-relieved the fiber optic feeding into the transmitter but that also did not fix this drift problem. I found that the alignment was sensitive to me pushing on a nearby cable tray that was connected to a conduit that was leaning on a copper pipe that the optical fiber was laying on (picture attached). The optical fiber was being tugged on by the copper pipe as well as the conduit and cable tray so we isolated the fiber to decouple the connection. After the fix, the drift was much better, about +/- 1 urad for the course of a few hours, this will hopefully be a good set up to take spectra and long term testing. Also, we re-centered the PR3 and BS optical levers and will continue to recenter as needed for testing by SEI and SUS.
Today's acitvities reported to the operator:
- Kyle R to LVEA to soft close GV5.
- Corey G and Keita K, working at End-X, TMS related work.
- Thomas V to work on ITM-Y OpLev, maintenance. Shutter between PSL enclosure and HAM01 was locked while work was done.
- Scott S, Mitch R and Lisa A, AOS/SLC Team to LVEA, End-X ACB build up.
- Betsy W and Travis S, End-X SUS work.
- Kiwamu I, to LVEA, check ISC table contents.
- Pablo D, Colin S and Craig C, work in the H2 PSL enclosure.
- Patrick T to both End stations, dust monitor work.
- Thomas V to remove lock from light pipe.
- Kyle R, to open GV5.
The dust monitors in the LVEA are NOT currently being recorded. It appears swapping the dust monitor in the H1 PSL enclosure has broken the communications.
Upon startup the IOC communicates correctly with each dust monitor until it gets to location 16 (the one that was swapped yesterday). After this it starts reporting back errors of the form: Error: ../commands.c: 49: Sent command � not echoed Received ?
I powercycled the Comtrol this morning. It worked after location 16 for a little while, but the error has returned.
Robert says he swapped the dust monitor in the H1 PSL laser enclosure. First one dust monitor was disconnected from the breakout box outside the entire H1 PSL enclosure. If I recall correctly, the dust monitor at location 16 was then still found by the IOC. The communication errors persisted. The first dust monitor was plugged back in and the other one disconnected. The IOC still found the dust monitor at location 16, but the communication errors went away. The dust monitor at location 16 reported calibration errors. It may be that the wrong dust monitor was swapped, leading to two set at the same location number, but this would not explain why the communication errors persisted after the first one was disconnected. As it stands, one of the dust monitors in the H1 PSL enclosure is disconnected. The dust monitor at location 16 is reporting calibration errors. I am not sure where the dust monitor at location 16 is. The dust monitor at location 10 is not found by the IOC. The remainder of the dust monitors in the LVEA are running again.
Sheila swapped the dust monitor in the anteroom with one programmed at location 10. The one she removed from the anteroom is labeled 'H'. It had no charge left in the battery when I got it. There was no change in the status. The dust monitor at location 10 is still unseen, and the dust monitor at location 16 is still giving calibration errors. This leads me to believe that: The dust monitor at location 16 is in the laser room and has calibration errors. The dust monitor at location 10 is in the anteroom and is unplugged at the breakout box outside the enclosure.
Today we installed 2 more accelerometers on the PSL table, one by where the water enters the high-power amplifier and the other by the PMC. We also removed the cover from the PMC. In addition we switched out the dust monitor which has been giving a calibration error message for some time (the 300 and 500 nm cutoffs may not be well calibrated). And we put up some signage related to switching between commissioning and science mode.
Attached are a set of directions for switching the PSL HVAC system between science and commissioning modes. These are also posted at the PSL. In science mode, only the make-up air, the air that pressurizes the PSL to exclude dust, is working, and only at 20% of capacity. In commissioning mode the make-up air is set at 100%, the HEPA fans are turned on to reduce dust, and the air conditioning is turned on to handle the heat load. The 20% make-up air setting does not seem to increase the dust load in the laser room, but the dust load does increase in the anteroom because the HEPA filters are off and there is no overpressure to keep dust from the LVEA out. Figure 1 shows 60 days of dust monitoring in the PSL laser room and the anteroom – most of the plotted time is in full commissioning mode, but the last three days (blue underline) show the dust status in science mode.
Nothing coming from the h1iscey model is updating. Jeff tried restating the model, then restating h1iopiscey, its still not running.
S. Dwyer, J. Kissel Knowing little about the iscey computer or its contents, but recognizing the frozen EPICs values, I had suggested that Shiela try to restart the front end process. After this had failed to solve the problem, I suggested taking down all of the user models and restarting the IOP process (note that this includes H1SUSPEMEY; sorry Robert). When the IOP process came back up from the start up, it complained of having NO SYNC, and all of its EPICs values had not kick started. Since this could be a problem that ranges in severity from "you jus need to hard boot the computer" to "the timing has crashed for this computer," we've decided -- after a days worth of debugging cavities -- that we'll just leave it for the expertise of the CDS crew tomorrow morning. We've left H1ISCEY with a hung but "running" IOP process, and dead user models. No Arm Cavity locking for tonight, kids.
[Stefan, Jeff K., Kiwamu]
We have aligned the BS this afternoon to maximize the amount of H1:ALS-C_TRY_A_DC.
This took some time since there was some confusion in the BS oplev and BS HEPI.
Current alignment biases :
H1:SUS-BS_M1_OPTICALIGN_P_OFFSET = -23
H1:SUS-BS_M1_OPTICALIGN_Y_OFFSET = 9
Current oplev nominal readout :
H1:SUS-BS_M3_OPLEV_PIT_OUTPUT ~ 5
H1:SUS-BS_M3_OPLEV_YAW_OUTPUT ~ 52
After aligning BS, H1:ALS-C_TRY_A_DC_VOLTS went to 0.3 which is higher than the value these days by a factor of 3. Also I see the red transmitted light becoming brighter as I aligned BS. This indicates that we are going back to the previous good alignment.
Before maximizing it we accidentally screwed up the BS alignment. It seems before Thomas centered the BS oplev the BS HEPI tripped for some reason. Therefore unfortunately the oplev centering was done with the wrong alignment. This complicated our alignment. Jeff untripped the BS HEPI with the intentional offsets enabled in V1 and V4 actuators which is the nominal configuration these days. Then we recovered the BS alignment by adjusting the top mass alignment biases. At the beginning we brought BS to roughly a good alignment by looking at the oplev trend and subtracting the offset introduced by the centering business. A fine alignment was done by maximizing H1:ALS-C_TRY_A_DC.
We were able to get H1:HPI-BS (in BSC2) running on Level 2, by - Running "ctrlDown BS" - Resetting all watchdogs - Turning on the master switch - Slowly ramping on the offsets using the master gain (which appears not to be controlled or used by the command scripts) - Hitting "isolate BS lvl2" The offsets buried in the V1 and V4 actuator filter banks, which are +2000 and -10000, respectively, were the major source of the H1 SUS BS misalignment. In case you missed it (like I did), Of the HEPIs involved in HIFO-Y, H1 HPI ETMY (in BSC6) H1 HPI BS (in BSC2) H1 HPI HAM1 are unlocked and floating, and controllable. H1 HPI ITMY (in BSC1) H1 HPI HAM2 H1 HPI HAM3 are locked.
I fixed a minor naming cut-n-paste error in h1iopsusex. I restarted all the SUS EX models to install the change. We will complete this modification tomorrow when we restart the DAQ (EDCU is purple partly due to this).
The EX software watchdog medm screen was created.
The daqd on x1dc0, x1nds1, and x1fw1 has been built from branch 2.7 and the data concentrator has been restarted to run the branch 2.7 versions.
JimW added another ~281 lbs to HAM6 and this got the lockers in the 'nearly loose' region. Temporary Viton was added under all masses. With it still locked, we then checked the Optical Table level and found it ~35mils runout. We loosened all the Horz HEPI set screws and then dropped the West-side corners ~1/32". This lowered the runout to <10mils and that is good enough to work on the ISI Lock/Unlock/Balancing. The HEPI Set Screws were resecured. Jim then worked on setting the Vertical CPS gaps/alignment. There may be a CPS Rack issue we need FClara to address tomorrow.
The x1work computer on the DTS is now running Ubuntu 12.04, updated from Ubuntu 10.04. A 1T hard drive was added as /data for database testing. Ubuntu 12.04 was installed on a separate 250G drive, the old Ubuntu 10.04 disk has been mounted as /usr1 in case there are files that need to be transferred to the new disk. Application software has been updated to the same software running in the LHO control room. The RSA fingerprint for x1work is now d5:ff:79:df:74:73:00:5e:89:06:ce:65:3d:8b:34:17
Daniel Halbe, Jess McIver
Daniel has shown a strong, persistent line at 6.8 Hz in all DOFs of the top stage BOSEMs of the ITMY since at least June 12.
As a follow up to his study, I looked for this line in the ITMY ISI and found it in stage 2: very sharply in RX, strongly in RY, somewhat fainter in Z, and much quieter in X, Y, and RZ.
The line is not seen in any DOF in stage 1, looking at the T240s.
Normalized spectrograms of representative DOFs are attached.
I have discovered a line very similar to this at Livingston and it occurs at 7 Hz. This line is found in Roll (very strongly) and not as strong in pitch. It appears to only show up in those two degrees of freedom and only in the top SUS mass. It does not show up in the ISIWIT channels or the top stage of the ISI. Also it does not show up in any of the other suspension stages.
I looked at spectrograms, time series, and ASDs for the CPS sensors on ST2 of the H1 ITMY ISI in all global degrees of freedom, but saw no evidence for a line at 6.8 Hz. An ASD of each CPS DOF during this time is attached in .fig form.
Alexa Sheila Stefan The I mon of the demod was not broken; I was using a bad cable to look at it. Now we are using the original demod again, using the I output, and the I mon and Q mon are on the scope visible from the ceiling camera (Imon is the x axis, Q mon is Y, both 500mV/div) We have the phase shifter still on external (remote controlled); the phase we are using now is 107.82 degrees and on the servo board IN1 polarity is negative. Right now we are locked with a gain of -8dB, and a screen shot of the IQ polar plot is attached. There is a lot of noise in I.
Summary: The HIFO-Y feature at 70 Hz is produced by both ALS periscopes on ISCT1. The features below 1 Hz are coherent with ground motion and OSEM sensors. We did not identify the dominant source of noise between 0.8 and 2 Hz, though this band contributes little to the HIFO-Y RMS. We may be able to reduce the RMS by using cylindrical periscopes that have resonant frequencies closer to 250 Hz, but we will also likely get a free factor of about two reduction in RMS (in the 60-80 Hz band) after noisy installation activities cease.
Vibration coupling to HIFO-Y was reduced by establishing a science mode and a commissioning mode for PSL air handling (Link). There remain two frequency bands that contribute significantly to the HIFO-Y RMS, 60-80 Hz, and 0.3-0.7 Hz.
Figure 1 shows spectra for the PEM sensors that we recently installed whose signals have the highest coherence with the HIFO-Y signal above 1 Hz. The PSL was operating in science mode. The accelerometer that we mounted temporarily on one of the two similar ALS telescopes on ISCT1 (red trace), the one that carries infrared light, has high coherence with and similar shape to the 50-100 Hz band noise in HIFO-Y (red and black traces). Further excitation tests on the ISCT1 table confirmed that the 70 Hz feature is associated with the lowest resonant frequencies of both ALS periscopes. Neither the green nor the infrared periscope appears to dominate, and I could find no particular source of, e.g., backscattering noise. It may be that the noise is associated with the differential motion of the two periscopes in the locked path.
The other coherence features in the spectrum are, at about 180 Hz, one of the higher-Q resonances of the PSL periscope – perhaps driven by vibrations at the 60 Hz harmonic. These 180 Hz vibrations may be smaller after installation, and if they are not suffieciently smaller, we may be able to damp at this frequency. The 12 and 13 Hz coherence regions are produced by table sway resonances of ISCT1. I am less certain about the feature between 5 and 6 Hz, but there is a building resonance at that frequency excited by wind. The seismometers, some distance from the PSL and ISCT1, also show strong coherence with HIFO-Y at 5.5 Hz, supporting the building resonance interpretation.
Coherences with features in the low frequency region are shown in Figure 2. Seismometer and OSEM signals have high coherence with the HIFO-Y signal, except in the band between 0.8 and 2 Hz. We did not find the source of noise in this region.
It may be useful for the DetChar group to look for coherence in this 0.8-2 Hz band (I only guessed the most important channels) and, if none is found, search for upconversion between the 0.1-0.7 Hz band and, say, the 1.2-1.8 Hz band.
It may be possible to reduce the ALS RMS by replacing the periscopes with periscopes that have higher resonant frequencies. We can probably get from 70 Hz to about 250 Hz by using the cylindrical periscopes from iLIGO. Stefan also suggested that we use a single periscope for both the red and green beams, reducing differential motion. I placed an accelerometer on the double periscope, also on ISCT1, and found the lowest resonance to be about 60 Hz. It is not clear to me whether putting both beams on a 60 Hz periscope or keeping them separate on 250 Hz periscopes, would result in the better RMS.
We may get a free factor of about 2 reduction in RMS contribution from the periscope motion after installation activities cease, because Figure 3 shows that ground motion in this band was about a factor of 2 lower during S6. After installation we would expect the ground motion to drop back down to the S6 level, reducing the need to change periscopes.
Figure 4 is a photo of the cylindrical periscopes from iLIGO that we gathered together near the squeezer bay with Corey’s help. None of them are complete, some parts would probably have to be remade.
Robert Schofield, Stefan Ballmer, Emily Maaske, Terra Hardwick, Vincent Roma, Brian Dawes, Tristan Shoemaker
I have computed the coherence between H1_ASC-Y_TR_A_NSUM_OUT_DQ and many seismic and suspension channels in the 0.1-2 Hz band. As Robert noted, there is significant coherence between many of the seismic channels and the output channel. There are also a few suspension channels that also indicate high coherence in the 0.6-0.8 Hz band. I can also broaden my scope if there is interest. This is a slightly random channel list, and if there are channels that people would think could be interesting, I am happy to include them.
