These are working again. We needed to align things on the table, as it was previously done with some random alignment.
The filter gains are +500000 counts for WFSA PIT/YAW and WFSB PIT, but -500000counts for WFSB YAW.
UGF is 10-12Hz for WFSA and 8Hz-ish for WFSB with these gains.
EPICS settings of the auto-centering servos.
Eight minute trend of the control outputs.
We are using a significant amount of the available range (±16000).
Eight second dataviewer plot of outputs (WFS_A PIT is bipolar, all other unipolar).
DAQ was restarted. Two changes:
The Hartmann sensor on ITMX measured the RH thermal lens in ITMX when 6W was applied to the RH. I'm satisified that it is installed correctly.
We need to install a beam tube between the viewport and the HWS table so, currently, the LEXAN cover is installed over the viewport (it was removed for the RH test).
The attached plot shows the measured HWS spherical power when 6W of RH power is applied. A negative lens starts to form about 10 minutes after the heater is first turned on - as expected. I turned the heater off after 35 minutes or so as this was all that was necessary to confirm that the sensor is working. Just after I turned off the RH, I replaced the LEXAN cover on the viewport (this is why the signal goes haywire).

Summary: The hauling of Hanford's orange rubble containers along Stevens Drive, through the nearby Wye barricade and onto the Hanford site continues to produce lots of 1-3Hz seismic noise at LHO on day shift and swing shift. This circumstance might not change much during the remainder of 2014. The swing shift noise might decrease in 2015. History: Hanford site activities that LHO feels the most are expansions of ERDF (the enormous rubble depository ~11 miles from LHO), the hauling of ~20-30 ton waste containers to ERDF and the return of empty containers out of ERDF back to the remediation locations. Pit expansions only happen when an existing supercell (hole) becomes full every few years. The excavation of a new hole takes a few months. The hauling of containers through the nearby Wye barricade is continuous. See this elog entry for some S6 plots of truck traffic. Current status of hauling activities: On a typical day between Monday and Thursday, 200-300 container trucks will pass through the Wye barricade on Hanford's day shift. 300-400 trucks will pass through the barricade on swing shift. The empty/full ratio for these totals usually lies within 30% of 50/50. [NOTE: These totals represent the highest possible values. The actual totals might be lower because not all trucks in the total might travel on Stevens Drive. Some might travel to other Hanford remediation areas on the far side of the site. This is one of several possible uncertainties in the haul numbers that I've received]. There is occasional weekend activity, but it doesn't appear to be significant. Operations schedules and interruptions: The trucks haul containers on both day and swing shift, but ERDF only operates the pit during day shift. The baseline schedule for the pit is four ten-hour days, but the pit will operate and loads will travel on Fridays as needed to catch up from lost time. The pit will shut down during high-wind episodes, but there's not a hard mph threshold for shutdown; wind direction matters. Pit operations also might halt for unusual circumstances related to particular loads. Although the pit might close in high winds, it's possible that loaded trucks could continue to travel since the containers are covered. It appears from the load numbers I've received that reduced pit activity correlates with reduced travel activity. These reductions are most evident on intermittent Fridays. Future activity: Day and swing hauling through the Wye barricade apparently will continue through the fall as crews continue to remove material from Hanford's 300 area north of PNNL and from the 618-10 area that's on the south side of Stevens between 300 and Energy Northwest. Hauling projections in part appear to be based on funding projections, which tend to fluctuate. Current circumstances suggest that the total number of loads in the winter will drop to a couple hundred per day, and it's possible that swing shift hauling could cease in 2015. Long term: The 618-10 site will remain active for several more years, and the 618-11 site near Energy Northwest's facility will ramp up and become active over the next couple of years. Attached plots: The PDF contains a set of recent 24-hour plots that start at 6:00 PM local time each day. These show the X and Z channels at EX in the 1-3Hz band. The last two plots are Fridays. 9/19 seems to show that the trucks were traveling in groups. 8/15 shows a moderately busy day shift and a quiet swing shift.
Aidan. Greg.
The ITMX HWS probe beam is now aligned to the test mass. Or rather, it is misaligned just enough to prevent a return beam from the ETM getting back to the HWS.
The conjugate plane of the sensor is within approximately 5m of the ITM HR surface (details of this measurement to follow).
The Hartmann plate is installed on the sensor and it is now running the HWS code. The code is broadcasting EPICS channels but is throwing up a warning about not being able to write the centroid data to file (I'll need to fix this).
I've now set the ITMX RH to 6W for a 45 minute test to confirm that the sensor is actually measuring something from the ITM and not some other spurious signal.
I did turn the table HEPA filter back on just before this measurement, so the temperature is dropping significantly on the sensor (which looks like a small change in the thermal lens)
Peter K, Sudarshan, Gabriele
With 160 W of power at the input of the IMC we expect 125 W at the IFO input. The beam sampler in transmission of the IMC collects 300 mW, of which 250 mW goes into the ISS array.
Therefore, with the present 10 W at the IMC input, we should have 15.6 mW into the ISS array. Of this, 1% of 50% goes to the QPD, corresponding to 78 uW on the QPD, and 1.95 mW on each photodiode.
The signal on the QPD should be 75 uW x 0.75 A/W x 100e3 V/A = 5.5 V or 9100 counts
The signal on each photodiode should be 1.95 mW x 0.75 A/W * 1600 V/A = 2.4 V or 3900 counts
SEI- Hugh running TFs on HAM6. Jim working on isolation filters on HAM5
SUS - work on quads for 3IFIO; last assembly almost complete. TMONS left to build.
TCS - X arm aligned. Viewport covers will be removed for more accurate alignment. Y-arm: wrong lens installed in vacuum - no point in trying to align at this time
CDS- cabling for aux systems continues. building RF box for 3IFO.
Commish - cont. alignment of DRMI this weekend.
I found the laser status screen indicating the "WARNINGS" had triggered. Went to the diode room to investigate. Found "NPRO switchoff during run" illuminated. I reset the laser, everything returned to normal. I have to look up what the error message means as I do not recall what it was for. There is no evidence of the NPRO dropping out over the past 48 hours. Attached is the trend data for the past month. No signs of the NPRO tripping out. Maybe a glitch set it off, or either the insertion of the reference cavity heater card or the outer loop power stabilisation card. Will check again on Tuesday to see if the condition crops up again.
no restarts reported
As preparation for automating the initial alignment, I did some things associated with the X arm locking.
(LSC-TRX_A_LF path was realgined at ISCTEX)
After the PSL light was locked to the X arm, I realigned TRX_A_LF path in order for LSC to be able to do triggered lock acquisition. The beam was already hitting the center of the bottom periscope mirror from the beginning. I steered the bottom periscope mirror and some optics in the down stream. I found that a lens had been taken out presumably due to the previous QPD work in this past July (see alog 12672). There was a post holder and a base plate secured on the table in front of the bottom periscope mirror. Looking around, I found a 2 inch lens (PLCX-50.8-515.1-UV-1064) with a post laid on the table. So I inserted it to the post holder and looked this was the right lens as the beam nicely converged towards the photo-diode (Thorlabs PDA100A).
Also, I put a temporary steering mirror aside. This is one of the mirrors that Sheila placed in this past July (alog 12672) and has been blocking the PDA100A. The DC voltage coming out from the PDA100A was about 300 mV with a 00-mode transmitted light on it. I did not check the gain setting of the PDA100A. The ADC count reached 1x104 cnts when the arm was locked on a 00 mode. Probably we will need to decrease the gain of the PD or that of the interface box at some point in the future in order to aviod saturation.
In addition, I adjusted the trans camera. I needed to move a black-place beam dump closer to a beam splitter which is the one before the PDA100A. Then I steered the beam splitter and the angle of the camera to coarsely center the beam in the view. I could not identify the channel number for this signal at the video matrix in MSR. Looks like channel #53 is it, but it keeps flickering for some reason and therefore hard to tell. Though, a 00-mode beam was visbile ocasionally. We need to fix this in the day time tomorrow.
(IM4/PR2 alignment with REFL9 WFS)
Instead of aligning IM4 and PR2 by hand, I started doing it using the REFL WFSs. I used REFL_RF9_A and _B and they worked well. Once I zero-ed the electronics offsets in the RF9 demodulated signals,they started looking reasonable. I closed two loops by feeding the A_RF9_I signal to IM4 and the other to PR2. IM4 turned out to be a well-diagonalized actuator in the sense that it was able to actuate mostly on the WFS_A signals. On the other hand, PR2 had some cross-coupling which is not surprising at all. I need to work on this a bit more in order to have more diagonalized servos. I did not precisely adjust the gains. So these are the remaining tasks.
Anyway, closing the loops increased the transmitted light and reduced first-order coupling from angular fluctuation of some optics. Note that I had the DC centering servo running in order to keep the spot centered on both WFS_A and _B.
Fil looked at the situation of the X arm trans camera. The bad flickering view went away after we power-cycled the video receiver/transmitter. He thinks that the AC adaptor maybe the one causing the issue. We will keep eye on it.
By the way, now we are confident that video channel #53 is the X arm trans.
Baffle PDs, now with the correct labels:
| TMSY | ITMY | ETMY | |
|---|---|---|---|
| PD1 | (-69 PIT, -71 Yaw) | (165, -105.3) | (62, -77) |
| PD4 | (-149.5 PIT, -2 Yaw) | (197, -139) | (91, -40) |
| centered | (-109.25, -36.5) | (181, -122) | (76.5, -58.5) |
Especially in pitch, these are rather different from what we found yesterday, which is not too suprising since we were hitting the ITM somewhere far from the center yesterday. There is a beam at the end station coming back from the ITM, and some fringing at ISCT1. To be continued....
The Y arm is locked on green. This morning I tried to focus all the ITM cameras, I still had some difficulty but the images are much better than before kiwmau adjusted the gains. We also changed the sign on the TMSY alingment slider gain, it is now -158.
This means that the PIT values in all of our past alogs will now be wrong by a minus sign. It also means that TMSY now has the same sign convention as all the other suspensions for pitch.
The atached screen shot shows the camera images, alignement biases, and beckhoff settings with green locked in the Y arm (although there is still a significant amount of power in higher order modes).
Note:
We only changed the slider sign because it was convenient.
However, if the BOSEM output should be consistent with Euler coordianate system, TMSY BOSEM input matrix and output matrix should be changed and the slider sign should be brought back.
Sheila, Kiwamu
We reconfigured most of the GigE cameras such that the analog gain is set to a high value in order to make the process of finding green light easier.
Now green beams as well as objects are quite visible on the cameras. For example, see the attached images below:
The camera image on ITMX looks similar to what Livingston has and therefore I am satisfied with the high gain setting.
(some details)
Sheila and I were having difficulty finding green light in most of the GigE cameras and therefore we had been wondering why they were not as sensitive as those in Livingston.
Looking at the camera initialization files in /ligo/cds/lho/h1/camera/ , we found a type which had been preventing the camera servers from changing the analog gain in its initialization process. In order to set the analog gain, the line should start from 'Analog Gain', but the line in all the files started from 'Default Analog Gain'. So we took out the 'Default' and reconfigured the servers by pressing the 'reload config' button in the medm screens. Due to this typo, all the cameras had been set to a default low gain regardless of what gain were requested in the file. According to the camera code (see camera_server.py in svn), the default analog gain is 100. We increased most of the camera gains to 1023 which is almost 10 times higher than they used to be. I am not sure if this is the highest, but certainly this was the largest number I saw among those files. In addition, changing the gain to some other higher value did not apparently make it brighter. So I guess that it should be already at the highest or close to the highest value.
Additionally, we found another typo in the initialization file: 'Default Exposure' should be 'exposure' according to camera_server.py. We fixed both typos in all the existing files.
Peter K, Sudarshan, Gabriele
As stated in the previous alog entry, we finally understood the cabling of the picomotors, and we checked that we can move all the four axis of the two ISS motorized mirrors.
We managed to get a beam on the QPD, with a total sum signal of about 12000 counts. Since the transimpedance should be 100k, this corresponds to something like 100 uW, which is even more that what we expect from 10 mW in input of the ISS array. So we are quite confident that we have the real beam on the QPD.
However, we still don't see much power on any of the eight photodiodes. The signal is something of the order of 5-6 counts at maximum for some of the diodes. Moving the picomotors while trying to keep the beam on the QPD didn't help much.
Searching for the maximum power on the photodiode is made difficult by the lack of a real DC output: the present board has a -20 dB gain at DC, rises with a first zero at 6 mHz, to about 60 dB at 10 Hz. This means that any transient in the power impinging on the photodiodes will easily mask the improvement we should get if the beam pass over the photodiode too fast.
So we modified the signal acquisition: using a DB9 break box we directly wired the test points after the transimpedance to the ADC, skipping the whitening. This modification has been implemented for PD1,2,3,4.
Moving around the picomotors we could finally get a beam on two photodiodes: PD1 sees something like 0.2 mW and PD3 something like 0.15 mW. This is still much lower than the expected ~1 mW per diode. PD2 and PD4 see some signal, but much smaller. We don't know what's happening to PD5-8, since they're still acquired with the whitening.
In this position, the beam is not hitting the QPD.
Aidan. Greg.
I fine-tuned the alignment of the ITMX HWS probe beam this afternoon. Actually, I'm now getting a return beam from ETMX, which I don't want, so I'm a little too close to a perfect retro-reflection. I'll detweak it tomorrow.
The camera has also been moved close to the conjugate plane of the ITM HR surface.
All of this was done with the LEXAN cover on the viewport. Further refinement will be necessary when this is removed. It should also clean up the return beam image.
The ITMX return beam is shown here. You can see the normal shadow from the baffles and the earthquake stops. There are no noticable stray beams coming from anywhere else.

I also misaligned ITMX to prevent the return beam getting back. Here's the return beam from ETMX. I know this is from ETMX because it swings back and forth when I put an injection into ETMX YAW.

LVEA is Laser Hazard 08:21 Hugh – Running transfer functions on HAM6 HEPI 08:52 S. Sachder – Going to End-Y to check PEM microphones 08:54 Danny – LVEA west bay to work on 3IFO Quads 09:06 Filiberto – Cabling ISS Array Picomotor (PM5) to HAM2 feed-through 09:15 Travis – LVEA west bay to work on 3IFO Quads 09:33 Karen – Cleaning at Mid-Y 09:42 Richard – Working on cabling for PM5 at HAM2 10:00 Adian – Going into the LVEA 10:15 Cyrus – Going to all outbuildings to property tag equipment 10:15 Betsy – LVEA west bay for 3IFO Quad work 10:51 Richard – Going to LVEA to work on cameras with Filiberto 12:58 Danny – LVEA west bay to work on 3IFO Quads 13:15 Travis – LVEA west bay to work on 3IFO Quads 14:15 Greg – Attaching flex tubing between HWF and HAM4 viewport 15:17 Sheila – Focusing cameras on both X & Y arms 15:42 Adian – Working on flex tubing installation at HAM4
All auto running under guardian, watchdogs if you please--H
Gabriele, Peter K., Daniel, Sudarshan
From our capacitance measurments (LHO: alog 14148), and the cable specification drawings: D1000581 and D1101515, we concluded that the picomotor on HAM2 are connected to the following channels:
Channel Picomotor
1 ISS (PM1-closer to the array)
2 IM4 Transmission QPD
3 Faraday Half Wave Plate
4 IMC Input Pointing
8 ISS (Before the telescope)
5, 6, 7 Empty
This is consistent with the channel assignment at LLO alog 12174
During the process we moved the Faraday HWP (Channel 3) and IMC Input Pointing (Channel 4) quite a bit, but we brought it back to its original position, atleast on theory. We moved these the same number of steps back as we moved forward and viceversa. :)
Picomotor code and wiki updated to reflect the revised motor assignment.