I went to HAM3 to see that the MC2 beam position wasn't crazy. See the first photo, the beam is to the left (+Y direction) relative to the baffle on the HR side but the baffle itself is offset in -Y direction relative to the cage.  Green lines are extension of the EQ stop screws to guide your eyes.

I also opened the ISCT1 and moved the mirror in front of the REFL BBPD out of the way and directed the beam to IFO REFL camera (because I couldn't see the beam at all without moting the mirror).

While manually aligning the IMC, we found that somehow things are in such a bad state that the MC2 TRANS SUM decreases when IM4 TRANS SUM increases, and vice versa. Improving the IMC alignment using IM4 TRANS as well as IFO REFL camera made the flashes stronger to the point that we can see 00 mode once in a while. I was also able to see the beam in the ISS path. But MC2 TRANS was nowhere near centered. Attempts to resolve this by incremental changes failed.

We wondered if something behind MC2 was bumped and changed the alignment into MC2 trans. I looked at the path and didn't see anything obvious. The beam transmitted through MC2 was visible using a card and a viewer, it was not clipped by the baffle behind MC2 nor the BS for the beam dump. I could not see the transmission of the BS, though, it was too weak, so I cannot confirm if the steering mirror in front of the QPD was bumped or not.

Elenna started making big changes for JM3 in PIT (to make big YAW changes in the beam injected into IMC, remember that YAW and PIT are flipped between JAC and IMC, IMC WFS takes care of this but that won't help when you're manually aligning JM3) and moving MC2 and MC1 so that the IMC follows the input beam. Repeating this in YAW anShe successfully centered the beam on MC2 trans. 

At this point I looked at the MC2 beam position again, see the second picture. Apparently the beam moved in YAW by a few mm to the right (i.e. -Y direction).

Elenna will post which optic was moved by how much in which direction.

Jenne is now trying to put IM4_TRANS and ISS QPD beam position back where they used to be using IM2 and 3.

Ibrahim, Betsy, Rahul

Today we glued two of the four AOSEM flag standoffs onto S2 of BBS01.

After gluing, we wanted to make sure we were contacted evenly so an hour and a half later, we used magnets to remove the flags from the glued-on mounts.

We discovered that some glue was touching the bottom of the magnet bushings, so we elected to use some foil as shims to create more space between S2 and the bottom interface of the bushings.

Otherwise, the mounts were flat on the surface. We put the bushings back on for the overnight cure. See pictures below.

TITLE: 05/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
SHIFT SUMMARY: The LVEA is still in laser hazard and will be for a few more days. The IMC alignment continues to prove difficult to get right. ITMY IAS finished up today. BBS work continues, CP1 regen, and more!
LOG:

• 1629 light pipe open                                                             

FAMIS 63898 (I think. With the new system there are duplicate tickets, so I picked the one that has a schedule assigned.)

No major events of note this week.

Micheal Ross showed up in the control room, so we spun up the NCAL.

It wouldn't spin at first because there was a current Latch reset button that needed to be pushed. Michael pushed System Reset and Latch Reset in rapid succession.
More documentation can be found here: LIGO iNCal Operating Procedures.pdf T2600149-v1. 

We ran it for 4 minutes 30 seconds starting at 21:25  UTC. 
H1:CAL-NCALX_MOVE_VELOCITY_VELOCITY_REQ was set to:  104 which translates to ~ 0.991 hz.
H1:CAL-NCALX_VELOCITY_KP_REQ: 0.0100 Mn/rad/s 
H1:CAL-NCALX_VELOCITY_FILTER_REQ: 5 ms

NCAL ran. 
Beckhoff I/O H1:CAL-NCALX_AXIS_ERROR_ID now has an Error status. 

Pressing the system reset button cleared this Beckhoff I/O error status indicator. 

Jenne reminded us that with the installation of the JAC, the process we use to offload the IMC WFS should be updated to use JM3's alignment instead of the PSL PZT since it's now the alignment mirror directly upstream of the IMC. I've done this in the IMC_LOCK Guardian node's code by essentially just doing a "find and replace" for the term "PZT" with "JM3" (and double-checking the result, of course), all of which happened in the OFFLOAD_MCWFS state. We'll test this state's functionality at a later date.

Changes have been committed to svn and loaded.

TITLE: 05/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 10mph Gusts, 6mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.12 μm/s 
QUICK SUMMARY: IPC errors on h1susMC2 and h1seiproc, dackill on h1iopseib2. All sus aligned and damped, SEI in state captured by the whiteboard. Temps look good and dust counts look good in the LVEA, the ends saw counts up into the 2000s during the last bout of wind 12 hours ago.

Laser hazard work in the LVEA continues today.

[Tom R, Oli]

Summary: QOSEM testing on the BSFM will require the tablecloth to be shifted OR SUSP to be raised, probably not worth the effort to do so given the BBSS will be ready for QOSEMs shortly.

Last Friday Oli and I attempted to install the QOSEMs onto the now removed from chamber and on test stand BSFM suspension, now that the IAS work was completed. The purpose of this test is to run and compare TFs taken with QOSEMs, providing a final functionality test before installation on the BBSS (which is not yet ready to accept QOSEMs). The full test and integration plan for the QOSEMs / BBSS can be found here T2600169.

We began by removing the SD BOSEM from M1 of the BSFM, and swapping the flag out for the QOSEM variety. We installed the QOSEM onto the cage, and used the existing DB25 in vac extensions and in air cables to run the QOSEM to its sat amp in SUS-R2. The QOSEM and its entire signal chain was functional, with readouts from this SD QOSEM appearing as expected in CDS. 

Unfortunately upon unlocking the suspension, to align this SD QOSEM, we found that its y axis could not be brought into range with the cams (at its best was ~1mm off). This is a similar issues we faced when setting up the BBSS at LLO. As the SD BOSEM does not have a readout in this 'y' or vertical direction, misplacement of the tablecloth by ~1mm is unnoticeable, and does not impede function of the BOSEMs, but as we are activity trying to readout this axis it does matter for the QOSEM.

As such, to setup the QOSEMs on the BSFM, we would need to raise the tablecloth, or SUSP via the blade spring angle. While this certainly could be done, at the moment this feels like an unnecessary amount of work to do for a quick test of the QOSEMs, given the BBSS will be ready shortly. For now we have abandoned this test, and removed the SD QOSEM from the BSFM, reinstalling the original BOSEM.

In order to search for retroreflections of scattered light that might recombine and cause scattered light noise, I take pictures from the point of view of the beam spot on important optics. The flash on the camera is right next to its aperture so, when the camera is held close to the location of the beam spot, the path of the light from the flash is similar to that of light scattered from the beam spot during observation, and glints in the photograph are indicative of potentiial retroreflections of scattered light. The distribution of light from the flash is, by design, more uniform than that of most scattered light, so more off-axis retroreflections in the photos tend to be less important.

An old photo taken from near the beam spot on PR3 showed a glint from an optic on the POP path so I re-took beam spot photos last week since we are baffling HAM3. The figure shows that I did not find a retroreflection in beam spot photos from PR3, but I did in photos from MC1 and from close to the center of PRM. I took beam spot photos with both my IR camera and cell phone – the figure shows cell phone photos as they are eaisier to interpret, but photos from both cameras show the same issues. I could verify these retroreflections and track them to their source by eye using a head lamp near my eyes. The PRM retroreflection is from the last optic on the POP path and the MC1 retroreflection is from the second to the last optic on the POP path (see diagram on the second page of the figure).

Im a little surprised that there are two of these random alignments, but I guess it is due to how small the angular differences between the paths from HAM3 to HAM2 are and the number of mirrors on the tables. I am also concerned that my beam spot photo technique only picks up retroreflections and not reflections of scattered light from one optic to a different optic. I would also like to make us more aware of these cross talk issues in planning optic paths and suggest that it might be worthwhile to develop code that checked for this.

I don’t know how bad these retroreflections are, but, in my photos, they are brighter than the reflections from ballast masses and the table that we are trying to baffle, so I may try to baffle the PRM retroreflection when we return to baffling. Im not sure how I could baffle the MC1 retroreflection without blocking the POP path.

No issues seen on CDS.

Jennie W, Madi S, Sheila  D,

Summary: JAC REFL A PD and WFS A and B are well-aligned and the beam is centred on the steering mirrors, but still some sign confusion on the readout for the WFS A quadrants and the WFS B DC readout (the QPD).

Earlier Madi and I went and re-centred the beam on the IOT1 steering mirrors JACR-BS3, BS4, M8, M9, M10. We then re-aligned the REFL PD and both WFS QPDs.

While centering we realised the degrees of freedom were switched.

After checking in the QPD input matrix for both WFS A and B, I found these were the wrong sign.

These matrix parts were copied from the IMC model and I didn't realise the IMC QPDs have a switch between pitch and yaw due to the periscopes that carry IMC REFL beam from MC1 to the in-air IOT2L.

I have switched both JAC QPD input matrixes to the values shown here.

I also checked the WFS I input matrix vales for A and B and these appear the have the correct signs for each quadrant.

Then I went to the table to do some sign checks on the QPD RF readouts to confirm these are hooked up correctly.

First I locked the JAC and then detuned it so the WFS signals are dominated by length noise. An offset of 0.4 in JAC-L_SERVO_OFFSET can be used to detune the cavity without unlocking.

Then I checked that the motion of the across the QPDs matches what we measure.

Moving anti-clockwise on pitch adustment knob for WFS A is down on QPD and on JAC-WFS_A_DC_PIT.

Moving left on QPD is down on  JAC-WFS_A_DC_YAW.

QPD A seems to have the correct matrix.

As I was doing these adjustments I looked at the four demodulated I-quadrature signals for WFS A.

Whent the beam moves down in pitch quadrant 2 and 4 go down and quadrant 1 and 3 go up - this is confusing as 1 and 3 should be diagonal from each other. See ndscope.

When the beam goes down in yaw quadrant 1 and 4 go up and quadrant 2 and 3 go down - the opposite way to what we expect from the motion on the QPD. See ndscope.

I did the same series of checks for WFS B

Moving anti-clockwise with the pico mirror pitch adjustment knob is up on the QPD itself but down on the WFS-B_DC_PIT channel, this is wrong.

Moving anti-clockwise with the pico mirror yaw adjustment knob moves right on the QPD itself and up on WFS_B_DC_YAW channel - this makes sense.

So maybe we need to change the input matrix for this or fix some wiring.

Still need to check the four demodulated I-quadrature signals for WFS B.

NB: Two months ago we started commissioning the JAC WFS and discovered that the X and Y on the A picomotor are swapped somewhere in the chain, see alog #89437. This probably needs the control wires swapped at the pico signal distribution box on the table itself but the picos are not hooked up at the moment as the controlled is shared with IOT2L which is unplugged for vent work in HAM2.

PSL power into JAC 200mW. Jennie was able to lock JAC without much problem.

Jenne put MC2 back to march 2026 (in-lock) alignment in PIT and YAW using osem (not the slider) taking into account ISI (HAM3) Rz. 

To see the fringes, we injected 600 counts 0.2Hz into H1:SUS-MC2_M1_DRIVEALIGN_L2L_EXC. IMC flashed right away but the transmisison fringe looked like a weak horizontal line. Moving MC2 alone did not make the fringe converge.

Jenne moved MC3 and MC2 (and MC3). Improved some but not drastic. Tried JM3, again improved, but not drastic. Jenne was able to see the MC2 TRANS SUM but it was awkward and slow. At this point, at least the beam was not a straight horizontal line any more, we saw HOMs both in PIT and YAW, sometimes even 10 and 01 and what might have been a dim 00 spot. According to Jenne, the maximum MC2_TRANS number observed (about 3 after subtracting DC offset with 200mW input) is about 10% of what we expect with a good alignment (300 counts with nominal 2W).

We need a better alignment to be able to see the beam in the ISS path, though, I couldn't see anything.

I wanted to see the PRM reflection on the ISCT1 REFL camera as it will make the alignment easier (because we can see the IMC transmission beam shape).

Inside ISCT1, the beam was making it to the BS for the 1F diode but was hitting the mirror holder of the mirror for the BBPD. I touched up the common steering mirror for 1F and BB (just downstream of the shutter) so the beam goes to the direction of BBPD (and of course 1F PD) but could not see the transmission of the mirror for the BBPD using a card and a viewer, probably because the power was too small. (We're injecting 200mW, MC2 transmission is a small fraction of that as of now, and the REFL path is supposed to handle 60W.) No beam was seen on the camera either.

On Monday we might temporarilly move the BS for the BBPD out of the way so we can see the beam on the camera.

I had a look at some of the data from Leo Schrader's SURF project, in particular the measured overlaps of the sqz beam with the OMC posted 86485 and the measured q parameters on SQZT7 posted in 86365.  

I first took the measured q parameters, and using finesse propagated them to the OMC and calculated overlaps, which are plotted as sqrt(vertical overlap * horizontal overlap).  The attached scatter plot shows the predicted overlaps compared to the measured overlaps as the ZM4 + ZM5 strain guage voltages vary.  You can see that for the nominal O4 settings of -0.4V ZM5, 6.2V ZM4, the measured q agrees pretty well with the measured overlap.  Moving away from the nominal values, some of the measured qs do not seem very compatible with nearby measured overlaps.  (note, these measurements cover the whole PZT range of 0-200V for both psams, the strain gauges just have different ranges.)

I then tried to use the overlap data to take a gues at what this means for the actuation range of ZM4 + ZM5 psams.  I used the following information from Camille to estimate the ROC of ZM4 and ZM5.  

• ZM4 is SN1, characterization data in E2100289 indicates that before the preloading was changed in chamber, with 0V on the PZT the optical power was -106mD.  In 75677 the pre-load was increased by 29 in lbs, T2300426 says the preload should increase the optical power by 2.4 mD/ in lb of preloading, so after preloading the optical power with 0 V on the PZT should have been -36mD, or an ROC of -55.5 meters.  0V on the PZT now corresponds to 2V on the strain guage.  
• ZM5 is SN4, E2100291 says with 0V on the PZT the optical power was 667mD with 20 in lbs of preload.  75709 says the preload was increased to 47 in lbs, so 27 in lbs of preload was added.  I assumed that the optical power change with pre-load is the same for ZM4 as ZM5, and estimate that the optical power after the pre-load change the optical power with 0V on the PZT should be 729 mD, or an ROC of 2.737 meters.  0V on the PZT now corresponds to -5.2V.  

I used these estimates for optical power with 0V on the PZT and varied a linear slope of optical power per strain guage voltage.  Assuming a slope of mD/V for each psams, I estimated the ROCs of each mirror.  For any set of psams slopes, I estimated the q before ZM4 by using the measured q for the nominal strain guage values of 6.2 and -0.4V. I flipped the sign of the real part and propagated it back to before reflection off ZM4 using the estimated ROCs for that slope, then flipped the sign of the real part again to reverse propagation direction. (Thanks Keita and Disha for help understanding how to flip the qs).  I then propagated that estimated q back through the ZMs allowing the strain gauge voltage to vary and calculated overlap with the OMC.  This approach garantees that the nominal strain gage of 6.2V -0.4V the contour will match the 2.3% mismatch estimated from the measured q there. It would be nice to do an actual fit, and also allow the ROCs at 0V on the PZTs to vary, to see if we can get a better match to the dataset that way.  

In the example contour plot I've put ZM4 at -10mD/V strain gage, which means -0.36mD/V PZT, and the O4 nominal ROC would be -25.6meters.  ZM5 is at -13mD/V strain gage, which means -.47 mD/V pzt and nominal ROC of 2.99 during O4.  

Lastly, I made a plot of propagation of the measured qs to the output of the AR side of SRM, that we can compare to Evan Hall's much nicer plots of SEC and arm cavity modes at SRM.  

The script used to make these plots can be found in the commissoning-modeling-repo here.

TITLE: 05/08 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

MC2 was fixed (cabling issue---see their alog).  ISS team went out to HAM2 late this afternoon.
LOG:

• 1513-1542 LVEA garb checks (kim.dawn)
• 1528-1536 MC2 work fixes continue w/ work at racks (Rahul)  
• 1549-1558 restoring mc2/pr2 cables (rahul)
• 1622-1628 reboot coil driver for mc2  (rahul.marc)
• 1655-1704 Dust monitor being power cycled, since it's been down (ryanC)
• 1645-1800 LVEA technical cleaning (kim)
• 1700-1830 Back to HAM3 for more checks (rahul.marc)
• 1703-1818 open light pipe, working on iot1, no locking for jac (jennie, madi)
• 1711-1945 BS/BBSS OSEM swaps (thomas.oli)
• 1745-2001 SQZT7 back panel off for table work (sheila)
• 1834-1852 Back to HAM3 area for another round of checks (rahul.marc)
• 1851-2000 Continuing JAC work at IOT7 & closed light pipe when out(madi.jennie)
• 1900-1947 EX grounding studies (robert)
• 2016-2110 Going into HAM3 for cable checks (rahul.marc)
• 2036-2300 FARO-ing ITMy @BSC1 (jasaon.ryanC.)
  • 2054-2300 Stephen joining
• 2110 Fixed MC2!  Mix up in the cable due to install and/or drawing (rahul, marc)
• 2125-2150 Woodland High School (Maggie)
• 2110 Continue ISS Array work at HAM2 (kieta,elenna,jennie)
  • 2255 elenna out
  • 2300 jennie out
  • 2305 jenne in
• 2110-2300 Checking IOT1 JAC stuff (jennie)
  • 2311 back out
• 2234-2305 PCal checks at EX (marc)
  • 2250 Marc plugged in cables and we have data for channels he was looking at
• 2239 EX grounding checks (robert)
• 2245 Checking on ISS work (rahul)
• 2315-2323 TCS chiller famis check (corey)
• 2327 Grabbing headsets for ISS array group (oli)

Marc, Oli, Jeff, Jenne, Richard, Betsy, Fil, Keita, Rahul

Yesterday afternoon, Jenne pointed it to us that she was struggling to point (move in pitch or yaw) MC2 suspension in HAM3 chamber - she was applying bias on Pitch dof and was not seeing optic move accordingly (this was to get the beam in HAM2 for ISS PD work). We then started troubleshooting  MC2. We started with the usual health checks (trying to damp the sus, TF measurements, M1 osem spectra) and it clearly looked that something was off - though we were not able to pin point on anything. Fil and I then swapped the cable 01 with cable 02 (basically trying to run MC2 using PR2 electronic chain for T1, T2, T2 and LF bosem - for ref. see wiring diagram D2300383, page 01 for MC2). When we (Oli and I) tried controlling MC2 using this, the results were all the more confusing.

This morning I restored the MC2 and PR2 cables back to its nominal state. Marc and I then started looking into the electronics chain of MC2 - poking each stage one by one. We started at Satamps (in the LVEA near HAM3 chamber) where I applied some offset at the CD on the medm screen and Marc measured the output voltage. For bosems T1, T2, T3, LF we measured 230mV and for RT and SD (these two bosems on MC2 share the electronics chain with PR2) we measured 350mV. We then moved to CER and repeated the same measurement at the MC2 coil driver and the result was no different. To check the DAC card and AI chassis we routed MC2 through another Coil driver (used by PR2) and yet there was no change in the output voltage. We swapped out the satamps and coil drivers to look for any change - found none. This meant that the electronics chain for MC2 was  healthy, hence we restored everything.

Richard then suggested to measure the resistance of the coils on the BOSEMs at the satamps. For T1, T2, T3 and LF it was found to be around 16 ohms (much lower than what we expect) and for RT and SD 40ohms (which is the correct value). Around lunch time Marc and I talked to Jeff kissel and everything at this point was pointing towards the suspension (either the bosems or their connection at the new feed through) in Ham3 chamber. After lunch time Marc and I headed to HAM3 chamber. After looking at the dust count (measured in lower 10s), I opened the curtains on the +Y side near MC2. I then identified the M1, M2 and M3 stage cable on MC2 and followed it to the connector on the ISI table. I then followed the table cable to the feedthrough connection (in vacuum side). Marc was standing outside the chamber near the feedthrough side (in air). I then started unplugging the cables on each stage one by one and initially it was very confusing but very quickly we realized (to cut the long story short) that - the M1 and M2 stage cables were not correctly connected at the feedthrough (in vacuum side - see D1002874). To confirm this we measured the resistance of the bosem coils at the D6 feedthrough in HAM3 chamber. The top F1 and Bottom F3 connection were showing out 16 ohms and the middle F2 was showing 40ohms. This told us that the middle F2 connection belongs to the M1 stage and the top F2 belongs to M2 stage - see below for clarity.

Given below the flange layout in HAM3 chamber (D1002874)- D6 F1 and F2 were incorrectly connected. Marc and I changed that on in-air side.
Old connection - D6-F1 F DB25 SUS MC2 M1 T1T2T3LF OSEMs. New connection D6-F1 F DB25 SUS MC2 M2 OSEMs
Old connection - D6-F2 F DB25 SUS MC2 M2 OSEMs. New connection D6-F2 F DB25 SUS MC2 M1 T1T2T3LF OSEMs
Did not touch - D6-F3 F DB25 SUS MC2 M3 OSEMs

 Oli took transfer function measurements and will post the results below. In the meanwhile we can say that MC2 is healthy and back in action.

Ryan Short, Tony Sanchez, Sheila

We took beam profiles of the sqz beam in the homodyne path using the Thorlabs M2Ms beamprofiler extension.  It made collecting data for a variety of psams settings much faster than using a scanning slit profiler alone.  

Tips for using this very nice extender kit:

• The visible alignment laser made alignment easy.
• We used the lens LA1461-C for 1064nm, the list of lenses and wavelengths is here: lens list
• make sure that the unit is plugged in, powered on with the power button, and connected to the laptop before you start the software.  Close and re-open the software if "translation stage control" and "M2 set" don't show up for you at the bottom of the "beam settings" window.  Once they show up you just have to go to the M^2 button and hit play to make a measurement.  
• You can get the fit beam parameters by saving a pdf by clicking the button that says "Save test Protokol", you have to hit save twice on the screen where you type a file name and again on the next screen.  "Save Measurement Data and results" gives you all the data, but not the fit beam parameters.  You again have to hit save twice.  
• Sivananda Reddy contacted Thorlabs and posted a diagram of where the reference plane is in the dcc: T2500077

We spent some time refinding the IR beam on the SQZT7 IR PD, documented this in it's own alog so it's easy to search: 90183

We set the profiler as shown in the attached photo.   The flipper mirror is 50.75" from the bottom persicope mirror, a steering mirror is 225mm from that, and the reference plane is 260mm from the steering mirror, so the reference plane is 1.774 meters from the bottom periscope mirror.  Leo Schrader has a helpful list of distances in the google document linked to T2500228.

• In 85282 Leo measured the beam distance from the top to bottom periscope mirrors to be 574mm. 
• The distance from the top of the persicope to the beam diverter was measured to be 84.5" in 61755.   
• In 75749 the distance from the beam diverter to ZM5 is listed as 1183.54mm based on a CAD drawing from Don Griffith. 
• This means the total distance from the reference plane to ZM5 is 5.678 meters.  We have left the profiler and temporary mirrors in place so that we can use them during the upcoming HAM7 vent.