WP 7222
FRS 4559
Continued with WP 7222, isolating the HWS cameras. Both end stations were completed today. Same steps taken as work done in LVEA, see alog 39532. All temporary power cables removed from enclosures and cameras connected to Hartmann Corner/End Station Breakout Power Chassis.
F. Clara, T. Shaffer
SamC and ConorML have designed some sensor correction filters using some matlab swarm optimization routines. Their designs are summarized in SEI log 1234 (yes, really) and a technical note in the DCC (https://dcc.ligo.org/DocDB/0147/T1700541/001/T1700541-V1.pdf ). I've installed these to test on ETMY and I'm leaving them running overnight. Microseism is pretty high right now so it's a good time to test. I've already collected some data, but the differences aren't dramatic, but I wasn't comparing very long stretches, I found a long window from last January with high microseism, that I'll try to use for comparison tomorrow.
First attached plot is the St1 Y motion measured by the T240 (thick lines), their RMS (dashed) and the ground motions (thin), red traces are for the swarm filters, blue are for the broadband filter we used during O2. Second plot shows the comparison of the CPS (SCSUM_CPS, thick lines), the cps RMS (dashed) and ground again (thin lines), again red traces are for the swarm filters, blue are for the O2 configuration. Last attached plot shows the two filter designs in displacement, and their complements, stolen from the DCC doc. Blends were not changed during these measurements.
Sam says that the filters were design when .1-.3 hz gnd blrms was around 450 nm/s. I've put ETMY back to damped to give them some time with higher microseism to design with.
K. Kawabe, J. Kissel, E. Merilh, C. Vorvick
Hoping not to have a repeat of yesterday's failed attempt at aligning the IFO by hand, we hit the whiteboard this morning to clearly outline our plan after Cheryl and Keita thought hard about what went wrong and what to do over night. Here's the game plan we're going forward with today:
Prep: misalign SRM, put face shield on ITMY
# Step Drive Optic(s) Alignment Metric
1 Input Align PSL PZT & (IM3 or IM4) PRM and PR2 irises, IR card
2 Check PR3 spot (if bad, move PR2) Target on PR3, camera viewer
3 Check ITMX Spot (if bad, move PR3) Face shield on ITMX, camera viewer
4 Retro Reflect back to PRM Walk PR2 and PR3 Return Beam overlap with forward beam @ PRM Iris, IR card
For walk,
move PR2 opposite of PR3 in Pitch
move PR2 same as PR3 in Yaw
For walk, move with a ratio of 9.7 : 1 in PR2 : PR3 step sizes
5 Check ITMX Spot (if bad, walk PR2 and PR3) Alternate between (face shield on ITMX, camera viewer) and (return beam Return Beam overlap with forward beam @ PRM Iris, IR card)
6 Check PR3 Spot Target on PR3, camera viewer
--------- PRM to ITMX is set. Do not touch Input and PR optics ---------
Prep: put face shield on ITMX, keep SRM misaligned
7 Check ITMY Spot (if bad, roughly adjust BS) Face Shield on ITMY
8 Retro Reflect IY back to PRM Walk ITMY & BS Return Beam overlap with forward beam @ PRM Iris
--------- PRM to ITMY is set. Do not touch Input, PR, ITMs, or BS optics until Step 11 ---------
Prep: remove ITMX face shield
9 Check SR3 spot Target on SR3, camera viewer
10 Check SR2 spot(s) IR card
11 Fine-tune ITMX and ITMX beam on SRM IR card
Walk (ITMY & BS) for differential spot change
Walk (SR2 & SR3) for common spot change / centering
For walk, move with ratio 5.8 : 1 in SR2 : SR3 step sizes
As we break for lunch, we're mid-way through step 5.
I attach a screenshot of our alignment offsets and OSEM values as we left it. #TouchWood
Sheila discovered an editing issue with ASC_COMMON.mdl using 2012b, which is not a problem with 2015b. Since we were planning on changing the default version of matlab for RCG model development to 2015b, I made the transition this morning.
I am seeing some warnings when starting 2015b, which I am working on removing.
Chandra noticed some strange dataviewer plots when asking for long look-back minute trends (see attached). After some investigation, I found:
The problem is with h1nds1's configuration of archived raw minute trends. The most recent archive spans the dates 5/26 to 10/18. The older archives are not being accessed, which I think is a result of my reordering the archived directories in the daqdrc file. After Dan and I had moved all the minute trends to their own RAID, I noticed that raw minute trends are ordered oldest-to-most-recent which would not be efficient since most data requests are for recent (within the last year). I reordered the list to most-recent-to-oldest and now only the most-recent directory is being read. When we are able to restart the NDS, I'll reverse the order to verify this. In the mean time, minute trends before 5/26/2017 are unavailable.
opened FRS9506 for this ticket.
The daqd process assumes that the list is from oldest to newest. This is how it has been since Alex Ivanov implemented it. Yes, likely need to improve documentation but usage has been limited to LLO and LHO.
Terry, Sheila, Nutsinee
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Yesterday we were able to get the SHG ~99% mode matched. After we tilted the first lens to avoid the back reflection into the laser we ended up with ~98% mode matched.
Given that we can find all the optics, we should be able to finish the rest of the table within a week or two.
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Other notes:
High power oscillator diode box current adjustment(s) [FAMIS 8449] With the ISS off, the diode box currents were adjusted. A screen dump of the laser main screen is attached.
| Diode Box [#] | Old [A] | New [A] |
| 1 | 52.3 | 53.0 |
| 2 | 54.5 | 54.8 |
| 3 | 54.5 | 54.8 |
| 4 | 54.5 | 54.8 |
Posted are the 30 day particle count trends for the LVEA. Mostly all good. The normal pattern of a few sharp spikes that clear quickly in random cleanrooms is repeated in these trends. The cleaning crew (Christina, Karen, and Vanessa) continue to do a fantastic job of keeping the LVEA clean and the cleanrooms are working well at cleaning up the air inside the cleanroom.
Betsy, Keita, Kissel, Cheryl
We spent all morning aligning the PSL beam from the IMs through the MC bypass, PR3, PR2, PRM, BS, ITMs, and back reflections from the ITMs reverse to PRM. We broke for a late lunch only to come back and find things misaligned again for unknown reasons. We spent a few more afternoon hours on this but will have to restart again tomorrow, since it seems we need to align the entire chain of 12+ suspensions in one foul swoop and we ran out of steam today.
Also to note, PR3 was fussy to use today - we couldn't get it to damp in all 6 DOFs and think we tracked it down to strange BIO settings which may or may not be stuck. Didn't have time to diagnose...
D. Barker, J. Kissel, R. McCarthy, V. Sandberg Problem with PR3 is confirmed to be a stuck relay switch on the T3 OSEM of PR3. See 39527 and/or FRS ticket 9497. Richard confirms that this requires a swap of the coil driver, so we've elected to punt the fix until later, since we have a functional solution.
During the installation of the OFI table into the cage some time ago, the table slid and came to rest against one of the corners of the cage cracking the beam dump, today I replaced the broken input baffle beam dump D1001920-v4 SN001, with SN003.
Since the reflection of IR beam on septum window AR is so small, we shot a red laser pointer beam from HAM5 through septum so the beam clears the HAM6 iris closer to HAM5, and falls on the second iris closer to VOPO within a mm from the center. Sheila calculated the deflection difference between IR and red, and it's so small it doesn't make much difference over the lever arm (a meter or two) in this case.
There were two beams coming through the septum, we took the first one (brighter, and towards +X) as the main beam.
There were three beams reflected off of the septum into HAM5. We took the first two towards +X as the main beams to dump.
We also confirmed that the scribe mark showing the thickest side of the septum is -X for the ZM path and +X for the OMC path.
Pictures will be added later.
1. Looking at the zm path septum window from HAM6. Laser pointer is in HAM5, already aligned. The beam spot on the septum is all inch or so away from the +X edge.
2. How the two AR reflections are on the beam dump but the third beam which should be AR of AR is not caught. This should be ok.
3. ZM path in HAM5.
4. ZM path septum scribe mark, -X.
5. OMC path septum scribe mark, +X.
SYSTEMS alert:
Potentially, the location of the HAM5 septum baffle needs to be adjusted accordingly because the septum window for the main OMC path is rotated 180 degrees WRT the design.
The first reflection by the septum window is not affected but the second reflection (i.e. reflection by the surface on the HAM6 side) will move from -X side to +X side of the first reflection.
TJ is contacting systems to figure that one out.
F. Clara, R. McCarthy, T. Shaffer
Work corresponding to FRS4559.
Summary: While we did manage to isolate the cameras from their base, the grounding problem still exists.
DetChar noticed a noisy source that turned out to be a grounding issue with the HWS cameras. The above FRS was filed and then T1600449 was created as a solution that LLO had found to isolate the camera. Just as T1600449 outlines, the camera base position was marked with some spare clamps, I then disconnected and removed the camera from the base, and then I laid the Kapton on the base. Reassembling this assembly required the use of a nylon 1/4"x20 0.5" screw to hold it from the bottom, and a removal of all other metal hardware. While I worked on this, Fil connected the shield to the Hirose connector. Once we were done, we plugged everything back in and tested it. No good. We double checked our work and couldn't find a source that might cause the grounding, so we unplugged the camera and made sure that it was actually isolated. It was. The LLO alog30372 said that they only checked it was isolated while it was unplugged. So we went hunting.
Fil poked around some more and then called in some backup from Richard. The three of us taped up the bottom of the power supplies where they contact the metal bars that hold them up inside the table enclosure (see attachments). This also did not work. Some more hunting from Richard found that the photo detectors were also grounding to the table, and possibly other sources. We could choose to find all of these sources and find a way to isolate them all, but for today this was where we ended. Tomorrow we will head to the ends to continue T1600449.
Attachments are: HWSY shown with position clamped and Kapton on, a taped base, and HWSX final.
Pictures of the power supplies taped up.
FRS9496
Jeff K, Richard, Dave:
At 07:30 PST Thursday 23rd November (Thanksgiving Day) PR3 rang up over two minutes. The T3 top OSEM shadow sensor RMS exceeded the 110mV threshold for 20 minutes continually, which caused the IOP Software Watchdog (SWWD) to DACKILL the h1sush2a DACs, at which time the oscillation stopped. The h1sush2a system remained in this state for the rest of the holiday weekend until the SWWD was reset this morning. Within an hour the ring-up occurred again. This cycle has repeated itself several times today. Investigation is continuing and an FRS has been opened.
Attached plot shows a 30 minute second trend plot of the Thursday morning event. Data shown is: T3's shadow sensor ADC channel (Ch 3), the h1suspr3 T3 DAC drive (Ch 9) and the h1susauxh2 M1 T3 Voltmon. As can be seen, the OSEM shadow sensor and the model drive ring up in Unisom, driving the coil driver. After the SWWD trips the DACs at the 20 minute mark, the coil driver is quickly zeroed, which causes a bumpy ring-down of the shadow sensor (which the model's output mimics).
Open FRS Ticket 9497.
PR3 Damping goes unstable because the Top Mass (M1) T3 binary IO switch for its analog low pass is stuck with the filter ON, implying the relay has became suddenly de-energized at 15:30 UTC (07:30 PST) on 2017-11-23. It has remained stuck there since. Logic thread that got me there: (1) The L, T, and Y damping loops (composed of LF, RT, and SD sensor/actuators) work just fine. Turn any one of the V, R, or P loops on, and they eventually (over the course of 1 to 2 minutes) ring up and cause the software watchdog to trip. (2) Had the binary IO screen open, just to show Siddhesh how they work. Noticed T3 was in the wrong state. (3) Toggling the state request (H1:SUS-PR3_BIO_M1_STATEREQ) from 1 (analog low pass OFF) to 2 (analog low pass ON), changes all the 6 OSEMs to be in the low-pass ON state. In this state, the digital compensation matches the analog configuration, so all is normal w.r.t. the damping loop plant. This is the configuration we ran in for the rest of the afternoon without problem. (4) Now, having a little time to think, I realize: when in state 1, the T3 OSEM's analog filtering is still stuck with its low pass ON, but the digital compensation compensates for the low pass OFF state. This changes the damping plant for *one* of the OSEMs, which is involved in all three, V, R, and P loops, and causes the loop to be unstable. Concluding theory as to what happened: The triple-top circuit diagram D0902747 (pg2, a zoom of the relevant portion of the circuit is attached for convenience) shows the energized (+5V to the relay, a binary, digital 1 sent through the BIO card) configuration, which is the low-pass OFF condition. When power is lost, the switch flipped to the de-energized (0V to the relay, a binary, digital 0 sent through the BIO card) configuration, which is the low-pass ON. This is what I think happened Thanksgiving morning: the relay (due to analog electronics failure) failed, switching the analog circuit to low-pass ON with the digital compensation still compensating for the low pass OFF condition, V, R, and P damping loops when unstable, rings up the suspension, eventually tripping the Software Watchdog. I'll update the FRS ticket and let the analog CDS team to put it on their "to-fix" list. However, because we can happily run in state 2, I don't suggest we take the time to fix it until we're done with IFO alignment, unless it can be fixed some morning quickly before the team gets started. For now, I've left PR3 in STATE 2, with the damping loops ON.
