Beam aligned to ITMX, ITMX aligned.

[Sheila, TVo, Jenne]

Today was an exercise in trying to get PRX aligned, so that we trusted our input beam and were on our way to being ready to align the HAM6 table.  So far, we think that we have the beam aligned to ITMX, and that ITMX is aligned well enough to retroreflect the beam.  We have not, however, been able to see flashes for PRX.  We are seeing fringing on the REFL camera, and on REFL_RF9_I.  Hoooray!  (This is a little bit stream-of-consciousness...we were definitely totally absolutely going home several hours ago)

• Moved IM4 such that we're hitting the ASC_POP A&B QPDs.  These are in the forward-going POP path.
• Moved PRM such that we're getting beam at the IFO REFL PDs and the camera on ISCT1.
• Moved PR2 such that we think we're centered on the aperture in front of PR3 (by looking at PR3 camera, which was refocused today).
• Moved PR3 such that the reflection from ITMX seemed centered in the PR3 aperture.  Note that this was done with the non-final ITMX position, but it's pretty close.
• Moved ITMX such that we see light on the LSC_POP_A_LF channel, the DC of the RFPD.  This PD is in the backwards POP path, so hitting it means that ITMX is retroreflecting the beam incident on it. Attached is a screenshot of the alignments in this situation (beam_on_LSC_POP_and_REFL_ITMX.png).
• Scanned PRM, looking at POP and some REFL signals in hopes of seeing flashing of PRX (peaks in POP diodes, dips in REFL).  So far, we're not seeing anything flashing.  So, pretty confusing, but if we're happy with the beam going to the ITMs, and can set the BS, maybe we don't care about the PRM right now, as we prepare to align HAM6?
• Noticed that it was possible to move ITMX such that there was more power on the ASC_POP, but we lost the power we were seeing on LSC_POP.  Sheila and TVo were able to walk ITMX and PRM such that they got light on both LSC and ASC POP diodes, which means that both the forward-doing and backward-going POP beams are hitting their PDs.  However, in this situation the beam is not going to the REFL port.  Attached is a screenshot of the alignments in this situation (Return_beam_on_ASC_POP_A_LSC_POP_from_ITMX.png).
• We'd like to see if there is a way to move the input beam, and then have the PRM and ITMX follow, such that we have beam on REFL, LSC_POP and ASC_POP all at the same time.  Hopefully this puts us in a place where we see PRX flashes.
  • Currently trying this, using IM4 to keep the beam on LSC_POP, PR2 to keep the beam on ASC_POP, and moving the PRM to get back to the REFL port.  When IM4 can't recover LSC_POP all the way, we moved ITMX a little bit (A thought - maybe moving IM4 was the wrong thing.  If we are no longer hitting the ASC_POP diodes when the ITM is misaligned, then we should undo the IM4 move and compensate with ITMX).
  • [some time later....] It's working!  We are seeing fringing on the REFL camera, and on REFL_RF9_I.  (screenshot attached: ITMX_beam_on_LSC_POP_ASC_POP_REFL.png)
  • I moved the RMs a bit to get centered on the REFL WFS, but maybe that wasn't needed.  We can undo as we like.
• We're getting some real fringes! We lost some of our power on LSC_POP.  Some of that was aligning for better fringes, but we also had a step that we don't know why we lost power.  Sheila had been touching PRM pit, but went back to where she started and the power didn't come back.  So, a little confused there, but very encouraged by our good fringes.  Screenshot attached showing alignment, and some fringes on dataviewer:  PRX_fringes_lost_LSC_POP_a_little.png.
• Currently adjusting ITMX to get back on LSC_POP, and using PR2 to recover fringes.  We got a little better, so we're attaching a screenshot: PRX_fringes_LSC_POP_recovered_a_little.png
• Heading home.

Plan for going forward:

• We also want to set BS + ITMY such that we get beam retroreflected to the LSC and ASC POP diodes.  We'll likely do this with ITMX misaligned, but once we restore ITMX we should be seeing MICH fringes. 
• It will help a lot to have the BS camera back online as soon as possible.
• Once the BS camera is back, it would also be helpful if someone had a chance to check other cameras on the output arm (SR optics).

Note from Cheryl:  There is some scattered light somewhere near the output of the Faraday.  She has a photo looking in one of the viewports, and it's clear that there's light in places where we don't want light.  Her suggestion was that perhaps the input beam is too close to a mirror near the output of the Faraday, and we're clipping.  Her proposed check was moving IM1 to see if that scattered light glow (as seen on the PRM camera view that she set up) changed.  Moving by a few thousand counts on IM1 didn't change the PRM camera image, so I'm not sure that it's the Faraday or the input beam we're having a problem with.  We'll continue checking on this in parallel with the main alignment work.

IO beam: suspected clipping on a IFO REFL steering mirror

• pictured shows the steering mirror for IFO REFL when PRM is misaligned
• in this picture the 2" optic is quite bright
• I suspect the main beam from IM2 to IM3 is clipped on the steering mirror
• I described the situation I believe we have to Jenne, and described how to test and correct the clipping
• snapshots show the steering mirror and the beam when it's clipping on the mirror, and the beam when it's well aligned and missing the mirror
• I did not see any other signs of clipping in the IO Faraday
• clipping on the IFO REFL steering mirror should be corrected, since that's a place where there's a power loss

Sqz Fiber Trans PD

The gain selection doesn't seem to work for the Sqz Fiber Trans PD.

BS oplev damping off

TVo noticed a moment ago, while we're trying to align the central part of the IFO, that the BS suspension was moving a lot.   A quick look showed that the oplev is quite far off the center of the QPD, and it looks like the servo is kicking the BS around a bunch.  For now, I've turned off the oplev damping on the BS suspension, but we should look into this in the near future (maybe we just need to center the oplev - are we still holding off on this for any known reason?).

Opened FRS Ticket 9737.

Field cabling for SQZ TTFSS High Voltage completed

WP 7295

Two PCX 200V power supplies were installed in VDD-C2 power rack and are being used to provide ±180V to the TTFSS unit on ISCT6 enclosure. New junction box was installed on top of SQZ-R1 rack and output ran to squeezer bay.

F. Clara, P. King, R. McCarthy, E. Merilh

Ops Day Shift Summary

ETMY SUS extraction Status

Between yesterday and today, Travis and I finished staging the weld room at EY:

- Finalized "furniture" layout

- Wiped all equipment down

- Worked through some power issues - need something from Richard, working on it

- Discovered the wrong blue duct jack Genie SUS lift was brought down - correct one brought down by Bubba this am

---

We also got the suspension to the point where we are really ready to put it on the install repair arm tomorrow morning first thing and bring it out for further disassembly:

- Staged in-chamber tools and pans

- Installed temp catch trays, face shields and added fiber guarding parts

- Pulled off all top mass BOSEMS and dropped the top mass down to make slack in wire segment below, used top stage to do this

- Pulled suspended lower cables up the reaction chain

- Removed a few large panels of flooring in the chamber in order to remove the sus structure sleeve, replaced the floor panels (note, found a bolt and nut under the flooring - also wiped the chamber bowl flooring many times to remove lots of particulate that looked mostly shiny, or PEEK, or viton)

- Adjusted all masses so that there was slack and removed the wire segment joint to the top of the UIMs

- Locked down all masses

- Laced up cables to arm elevator and tested functionality

 

We should be ready to start the extraction tomorrow morning, barring telecons, etc.

 

Power-cycling ETMX T240 chassis fixed 85mhz noise?

Following the work I did in alog 40109 , this morning I tried a couple of other things. I put the ISI in damped state, and turned off the suspension damping loops, this didn't change anything. After, that, I restored the suspensions, recentered the T240s (with the buttons on the BIO screen) then drove to the end station and power cycled the 3 T240 chassis for the ISI (I left the box for the ground sensor alone). This seems to have fixed the 85mhz line in Z3. Looking at the coherence between the 3 sensors seems to be the easiest way to see if the line is still there, see attached plot. Red (Z2-Z1) and blue(Z3-Z2) are a measurement taken after the chassis power cycle, green (Z2-Z1) and brown (Z3-Z2) are from before. The dip at 85mhz in the brown line (caused by, I assume, the excess noise in Z3) is gone in the blue. I'll monitor, but I hope to never see this again...

Added Command Line Functionality to cdslib.py

I was tired of getting a DCUID and trying to figure out the model name or vice versa, so I added some argument parsing to /opt/rtcds/userapps/release/sys/common/guardian/cdslib.py

---

Example usage after aliasing cdslib='python /opt/rtcds/userapps/release/sys/common/guardian/cdslib.py': 

thomas.shaffer@zotws8:~$ cdslib -h
usage: cdslib.py [-h] [-p] [model]

positional arguments:
  model              Give the model name or dcuid # and it will return the
                     compliment.

optional arguments:
  -h, --help         show this help message and exit
  -p, --printmodels  Print the total list of the all models and their dcuids.
thomas.shaffer@zotws8:~$ cdslib 117
h1calcs
thomas.shaffer@zotws8:~$ cdslib h1calcs
117

Added X & Y to RZ decoupling to the HEPI Cartesian IPS Align on ETMX HEPI

Look forward to having a locked IFO with ASC signals to further confirm but this has reduced the length to angle coupling by a factor of 5 for X and a factor of 10 for Y (assuming the Len2Ang coupling coefficients in E1200836  are correct!)  This difference is only because the coupling was worse for Y.  The residual with a 200um stroke is now ~0.1urad for both X & Y drive.

See the first attachment for the before picture--this is a repeat from aLog 40106.  That log details the production of the residual Optic motion due to the X & Y stroke shown in the upper right two graph with the black trace being the residual after the length to angle coupling is removed.

Running a couple strokes of sufficient amplitude gave enough info to compute a zero coupling coefficient for the HEPI X & Y to RZ.

The 2nd attachment shows some tests with various IPSALIGN values for Y motion.  There is no oplev len2ang coupling in this DOF.  Final value of -0.0055 reduces the Y to RZ fairly completely.

The 3rd attachment has just the final result using 0.0031 for the X to RZ IPSALIGN value.  The red traces are the X drive and the OpLev outputs.  The blue traces are after the OpLev len2ang coupling removed.  Can't do anything about Pitch but the YAW is pretty much gone.

These values have been accepted into SDF.  Will do ETMY when possible.

Some changes to seismon code, troubleshooting added to wiki

Our local copy of the Seismon code has been running pretty well for the last several months, but one of the python epics scripts has been crashing ~ once a week. Typically, it's pretty easy to recover : ssh in to the hwinj2 machine and restart the crashed code. This week, more of the seismon earthquake code had crashed, which is new, but I'm assuming this had something to do with the computer restarts yesterday. When I was fixing this, I finally got smart enough to ask for some help on the more routine crash, and Michael Coughlin suggested add some try-except loops to the epics code. So, before the lines 209 & 239 were both:

 (eq_file, eq_gps, eq_mag, p_arr, s_arr, r20_arr, r35_arr, r50_arr, rvel, gps0, gps1, lat, lng, dist, depth, azimuth, dum, location, ifo) =  line.split()

These lines are now:

try:
     (eq_file, eq_gps, eq_mag, p_arr, s_arr, r20_arr, r35_arr, r50_arr, rvel, gps0, gps1, lat, lng, dist, depth, azimuth, dum, location, ifo)
 =  line.split()
except:
    continue

Still running so far. I'll keep an eye on it.

I've also added a troubleshooting section to Dave's seismon wiki page, https://cdswiki.ligo-wa.caltech.edu/wiki/seismon . I think these instructions I added under LHO Troubleshooting should be enough to recover the code from most of the failures I've seen so far. 

ISI CPA Spectra Checks (FAMIS #6933)

   Posted are the results from the HAM and BSC CPS Spectra noise checks. There are a couple of signals above the reference but nothing to bee concerned about. Closing FAMIS task # 6933

EndY HEPI System fluid filters changed--back to local recirculation

Jim and I changed the filters yesterday and are running the system manually recirculating just at the pump station.  The recirc return valve is choked down to increase back pressure to expose leaks.  Please do not operate any of the HEPI system valves and be cautious in the neighborhood if you have activities there.  We'll run in this mode for at least a week.

Weekly PSL Chiller Check (FAMIS #6558)

   Peter noticed the Crystal chiller was signaling a low water condition. He added 250ml to the Crystal chiller. The Diode chiller and the filters are all OK. Closing FAMIS #6558. 

a first look at alignment downstream of the IMC

Since we have the mode cleaner back, and Jenne has done a little maximizing of the cavity build up, I had a first look at alingment downstream.  I found that IM3 PIT was at +11000 pitch in slider units (which are not urad for the IMs), and that the beam was low on IM4 trans QPD.  By moving IM3 pitch to -7000 cnts, IM4 trans sum was increased from 26uW to 42 uW.  During O2 it was about 45 uW with 2W into the mode cleaner. 

I moved on to looking for the REFL beam by setting PRM to the nominal "aligned" guardian state.  There was nothing on the camera; I went to ISCT1 and I see no beam coming onto the table.  I tried turning the power down to 1 W into the mode cleaner and putting excitations on PRM pit and yaw for a few minutes, but saw nothing on any of the refl diodes.  The mode cleaner had difficulty staying locked at 1 W.  

It seems like the next step is to look in some viewports on HAM1/2 to see if we can see a beam.  

Wrong cable connection. IMC length RF and WFSA 1st quedrant RF were swapped. (Jenne, Sheila, Cheryl, Daniel, Keita)

After Jenne changed the IMC alignment, some serious optical gain was still missing for IMC locking, but the power of the MC2 transmission was decent, IM4 trans was decent,  alignment was decent, LO level at demod was decent, and finally I got suspicious about the cables.

See attached, the first one shows the IOT2L feedthrough panel for IMC length diode. Connector for RF4-IB actually goes to RF8-1B, which is WFSA quadrant 1. The second picture shows that the connector for RF8-1B accepts RF4-1B.

So, all two weeks we've been locking the IMC with one quadrant of IMC WFSA, and we've been moaning that WFS doesn't work.

The connection was corrected, phase shifter was set back to the old setting (6.375ns delay) and the optical gain was back to where it should be.

RF readbacks

Some strange readbacks in ASC-AS_B_RF42_DEMOD_LOMONCHANNLE_3/4 and LSC-REFLAIR_A_RF45_DEMOD_RFMON.

Readback error on AS B 36 whitening

Keita noticed just now that there is a readback error on AS B 36 whitening gain.  We should fix this before we start needing AS WFS.