FYI - The EY wind channel died ~2 hours ago. Richard reports that "someone was working out there and it's probably related."
While poking around looking at screens in the control room this morning, I noticed the ETMx OL sum is was low. Some trends reveal that there was a drastic drop of the laser power on the QPD on Sat morning. A trend of ETMx signals, as well as some ISI and HEPI signals (not shown), indicate those systems are ~healthy. So, it does not seem that the physical pointing of the ETMx via SUS or SEI has changed the pointing on the OL. Note, this happened a day after the Fri EQ which caused all the ISIs to trip. Likely we should investigate the OL itself to see what's going on with the laser beam/QPD.
Arnaud reports that at ~midnight last Friday night, all of the ISI tripped due to an earthquake. There was a magnitude 6 EQ in Mexico May 10 07:36 UTC which correlates to the ISI's tripping at 07:50 UTC.
cf alog for ISI plots
Gerardo says there is an earth quake on the oregon coast, so far end X is the only one tripped.
Here is the last 30 days of YEND temperatures. Shown is the LVEA average and two of the four zones from which the average is derived.
The large positive spike is experimentation with chilled water flow - (Robert and John on 4/20).
The smaller negative going spikes are not explained but may be related to human actions as I have stopped and started chillers several times in this period for diagnostic purposes.
It's not clear what caused the trips from this morning. The ones from Friday night seem to be related to earthquakes.
It's not a problem for now, even if we use oplev damping, because the oscillation leaking to the oplev error signal (attached, a tiny bump at 0.32Hz for green curve) is small enough.
Anyway, it seems like this has been going on for the past four weeks (second attachment), and even if it doesn't get worse, oplev people should look at it after the integration test.
Oplev SUM peak-peak was a factor of 10 worse before it settled down to the current state (beginning of the second attachment), but I cannot see the raw data so we cannot say what was going on then.
no restarts reported.
model restarts logged for Sat 10/May/2014
2014_05_10 05:02 h1fw1
2014_05_10 18:42 h1fw0
both unexpected restarts, not simultaneous so no data lost.
No restarts reported.
(Daniel, Alexa)
Over the past few days we have been working on ISCT1 in order to measure the noise produced by the difference in path lengths between the POP beam and the PSL reference beam. See alog 11748 and alog 11737.
To complete the installtion, we aligned the BBPD and borrowed 15V power supply used for REFLAIR B BBPD on the table. We measured the power of the PSL reference beam to be 95mW before the SHG, 90mW after the SHG and dichrioc, and 12mW after the ND06A and 50/50BS. With the BBPD responsivity of 0.1A/W and 2kOhm trans at DC and RF, this amounts to 2.4V at DC. We measured about 2.5V at DC. Meanwhile for the POP beam with PRMI locked, we measured about 50uV (consistent with the 172nW --> 35uV we measured with PRX locked previously). With these values we expected a beatnote signal of about 10uV or -30dBm. Looking at an RF spectrum analyzer at both 9.1Mhz, and 45MHz, we found the beatnote maximum to be about -45dBm; this was consistent enough with our estimate since our alignment on the PD was not very good.
We borrowed POP_A_RF9 to look at the signal and added an RF amplifier of +30dB, and +30dB whitening gain. It was unclear to us whether we were seeing turn-arounds or fringes. We tried splitting the signal between RF9 and RF45; however, these appeared to be in phase, so this did not help us. Since we had PRMI locked during this measurement; its likely we lose some of the macroscopic length difference that arises when the cavity is moving freely during ALS. We repeated the above measurement with PRM misaligned and only using the straight shot. I have attached the time series and power spectrum displaying the result. Using the rms of the time series, we calibrated the power spectrum into rad/sqrtz for red. The ALS beam to ISCT1 is green. Since the fringe speed will be twice as fast, we must also shift the frequency to 2f (not shown in DTT image).
In the second plot I have attached, the green trace is the out of loop infrared noise for ALS COMM we have been using ( in particular from alog 11106). Meanwhile, the blue trace is the power spectrum calibrated back into red. From 1 to 10Hz we see that the noise produced from this path difference is very consistent with the 1/f noise we have been hunting. The measurement probably does not hold above ~20Hz.
Switched all Guardian medm calls on the main Guardian screen, the IFO align screen and the ALS screen to a standard medm display call. This fixes the long-standing issue of Guardian not popping up. For this I made modified copies of two guardian screens: sys/common/medm/SYS_CUST_GUARD.adl (a copy of the GUARD.adl screen in the guardian distribution" sys/common/medm/SYS_CUST_GUARD_OVERVIEW.adl (a copy of the GUARD_OVERVIEW.adl) These screens now point directly to the medm screen, instead of calling guardmedm. I also updated the IFO_ALIGN.adl screen and the ALS_CUST_MAIN.adl screen.
ETMX tripped @ 1083716829 because the IOP dackill tripped because of a suspension measurement.
Today I updated by as-built drawing for the RFM networks down the X and Y arms (DCC D1200562). I found that the order of nodes in the X and Y arm loops are not the same (see figure below). This may explain why the LSC receiving error rate of data from h1iscey is greater than that from h1iscex. In the Y arm loop, there is the maximum number of nodes between the iscey and the lsc, while on the X arm loop the two other nodes at the end station and not "in the way".
We will work next tuesday to make the two loops the same.
SR3 needs to be pushed to the east to correct the longitudinal error, and if we correct some of the lateral error in the process I won't complain. We will commence with the pushing of the suspension on Monday.
Note, to get here, Jeff, Andres, and a little bit of I, connected up the remaining OSEM connections in and out of vacuum. Jeff and Andres then suspended the masses and verified damping works. They installed the corner cube assembly (with a minor hiccup). Then, I ran quick L, T, and V TFs - all of which looked clean, so the numbers Jason states above are true.
I'm covering for Jeff B from 8:00am-2:15pm
Day's Activities
14:40 Dave - Back from end stations and going to SB to work on test stand 14:58 Gerardo - Working in H2-Laser enclosure 15:05 Mitch & Travis - Out of the LVEA 15:46 Gerardo - Out of H2-Laser enclosure NOTE: Sheila is running a long test on ETM-X. If the watchdogs trip she asked they NOT be reset
Yesterday night, I tried to run SR2 M2-M2 and M3-M3 (lower stages) in chamber transfer functions after the osems were centered on wednesday. Although both M2 and M3 watchdogs tripped during the measurement, so I am running it again tonight. (This time, I decreased the drive and increased the watchdog threshold).
Decreasing the drive didn't help either since I ended up with measurements without coherence. This morning I tried to drive M2 stage with high amplitude sinewaves at the resonant frequencies of the suspension for each DOF (L P and Y) to see if the osems would saturate. They don't. So a drive of 500 000 (cts) for L and 20 000 (cts) for P and Y (which is the limit before saturating the DAC) should be optimum at all frequencies. Started a new measurement which will run today.
This time, phase 3a M2-M2 and M3-M3 measurements of SR2, in air, with the HAM-ISI locked were succesful. The actuation is functioning, and the transfer functions for the three degrees of freedom are similar to the model.
There is one interesting feature to note for M2 stage. From 10Hz, the measured tf rolls up, as if some extra zeros were added to the tf. I checked the osem output filters, and they seem to compensate correctly for the coil driver (looking at the state diagram in state 1).
Attached are some SR2 phase 3a spectra for future reference
(David H, Thomas V, Greg G, Alasitair H, Matt H)
Well if yesterday was "The Empire strikes back", today was "Return of the Jedi" and the good guys had a win.
You may remember from this mornings alog that we had been having a few troubles with the alignment of TCSx.
After a brainstorming meeting with Aidan the decision was made to ignore the path defined by the flipper mirrors having problems with (what is supposed to be the central heating path) and align what is the annular heating path (which only uses mirrors) to the output beam splitter and through the irises defining the beam path up the periscope, into the chamber and onto the CP. We will then use the central heating mask instead of the annular heating mask (in the location the annular heating mask would be ), and thus temporarily turn the annular heating beam path into the central heating beam path.
The first step we did was to use a HeNe beam to adjust the output beam splitter and the beamsplitter just before the on table power meter so that the front and back reflections were in the same plane (they werent installed that way). We then went all the way back to the first large gold mirror after the polarisers (which are after the beckhoff controlled HWP) and mirror by mirror in the annular (now temporary central heating) beam path made sure that they were set so that the beam was in a plane with the table at a height of 4 inches.
Once the beam got to the output beamsplittler, the beamsplitter and the last gold mirror before the periscope was used to align the beam to the irises that we had defined to put the beam correctly into the chamber. I roughly made sure that the beam transmitted through the output beam splitter was going to the on table power meter, and the beam path that would go to the FLIR camera was beam blocked as I no longer no that the beam path is correct (I removed the lens there so that needs to be reinstalled).
A HeNe beam was setup to trace through the irises (heading in direction of going towards the periscope). Once the optic beam path had been re-established I swapped out the 1" irises we had (which had clipping on the beam occuring) for 2" irises. We then inserted a 2 inch gold mirror into the path between the 2 irises and sent the HeNe beam down towards HAM5 and the target that we had set up at a distance that mimicks where the CP would be. An "X" was marked on the card and the HeNe aligned to this "X' and the FLIR camera setup so that this spot was centered on the camera.
HeNe beam removed and the CO2 beam projected onto the target. Good to see that the CO2 beam appears to hit exaclty where the HeNe indicated it should (lets out sigh of relief)....so this should mean that the CO2 beam should go into the chamber and onto the CP correctly. Whilst doing the projection we also placed in the central heating mask (it has been rotated 90 degrees so that the rejected beam is directed towards the edge of the table not the center of the table as indicated in the drawing because the beam dump would not fit) and used the projection to help center the mask. Worked well...and success was declared. I dont have the pics of the projection, but pics were taken.
All beams have beam blocked so that if wanted to run the laser around the clock we can (we wont be until given the go ahead by the local LSO). A bugzilla list (Bug 868...https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=868) has been made of the tasks that can think of that are still outstanding/need to be done for this table.
One concern: A couple times today we had further issues with the HWP. We would dial up an angle for it to go to, the MEDM screens would indicae that the HWP was at the angle we had requested yet it physically was at a different angle. I have asked Thomas to look into tomorrow as this is a concern.
Pic:
TCScurrentalignmentstanding shows a quick summary of whats aligned and what still needs to be done
Awesome work. Great job doing a difficult operation in a safe manner--thanks. I think we can start running TCSx unattended starting Monday.
Some pictures from the FLIR of the projection in action. These pictures show the projection and the projection through the heating mask onto our paper target. The heating seen was about 2° C above ambient and the ruler in the picture is 12"
Pics of projection setup and also the table as it stood when I left thursday night
