Robert, Sheila, Eric, Daniel D

Yesterday morning we were able to identify the source of the scatter in HAM7 as being SFI2, and notice that the beam is very off center on the polarizer on the ZM4 side of SFI2, B:P2.  

We locked the OMC on a single bounce beam with 50W input to the IMC, and turned on the ISS second loop, and got 67mA DCPD sum.  With the viewport on the HAM5 gate valve and a 1 Hz excitation of 1000 counts amplitude on ZM5 TEST, we could clearly see a fringe wrapping shelf at 140 Hz.  We used a piece of black glass to block the beam and could see the scatter shelf go away when the black glass was after B:P2 and reappear when the black glass was before the rotator.  

Robert got some photos of the location of the beam on B:P2, it is clearly off center and near the +Y edge of the polarizer aperture.  We attempted to steer the ZMs to bring it close to the center, but we clipped the beam on the aperature attached to B:L2 before we could bring the beam close to centered.  This indicates that this path was aligned with the beam poorly centered on the Faraday.  

TITLE: 12/19 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 5mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.45 μm/s 
QUICK SUMMARY:

• IOT2L table work, disconnecting and moving it
• More HAM7 chamber work
• HAM1 chamber work
• IAS HAM1 support tubes surveying if HAM1 work allows

M. Todd, G. Vajente, L. Dartez

Thursday 12/18

1. We compared the beam profile that we fit to the modeled beam in that region, as well as what both of these beams look like at the ITM. We were initially very confused so we went back and more carefully placed the optics, taking care of the of and between the lenses in the telescope.
2. It seemed that the astigmatism was much worse than anticipated so we thought about tilting one of the lenses and seeing if we could compensate for the astigmatism. This gave us pretty confusing results, and especially because the fit to the first dataset was yielding non-physical values. For reference, the fit is done by fitting a quadratic to the beam radius squared as a function of z (i.e. w² = a+bz+cz²).
3. After deliberating in the control room, and returning to corroborate the fintrace model with jammt, we came to the conclusion that the telescope model is sensible; however, the measurement that we were taking is not descriptive enough of the beam to understand how the active telescope performs.
4. We finally decided to go in and take out the pick off to get as close of beam profile measurements to the waist of the beam after L2. We then shifted L2 5cm back toward the laser which was closer to the nominal position in the modeled layout. Here are the two plots of those beam profiles with their fits (I used a quadratic allowing M2 to vary, Gabriele has plots of minimized error of a Gaussian beam). L2 5cm further from M1 than the model. L2 close to model nominal position.

TITLE: 12/19 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE for PLANNED ENGINEERING

Summary of activities today:

• HAM7 Scattered light investigation, IMC locked beam out of HAM5 - IN PROGRESS, scatter found
• HAM1 Continued investigation into JM1/3 OSEM/controls issues - DONE, both JMs working - alog 88599
• HAM2 Move IOT2L away from chamber - TMW
• HAM2 Lock HEPI - DONE
• HAM2 Removal of PEM Support tube plates - DONE
• HAM4 AIP work, pumps on and off - TMW
• South Bay crane pendant work - DONE
• BSC2 Prep work in West Bay cleanrooms and platform - IN PROGRESS, mostly done

LOG:

[Daniel, Kar Meng, Eric, Sheila]

This afternoon, we continued with the realignment of the VIP after the VOPO swap.  When we first started, we briefly lost the CLF input alignment between the fiber and the VOPO cavity.  It turned out that the collimator was loose in the mount.  We took out the collimator holder and noticed that the 2nd grub screw hadn't been tightened all the way.  After fixing, we realigned the cavity till we could see a reasonably strong beam in transmission while the cavity was scanning.  

We then began the painful process of aligning the weak transmitted beam through the various components in HAM 7.  Using only the first steering mirror between the VOPO and SFI1 on the VIP, we managed to get the beam roughly aligned up to FC1.  However, we couldn't quite figure out how to get the return beam from the filter cavity retroreflected through SFI1 again.  We eventually decided to move FC1 a bit to get the beam back through SFI1, through SFI2, and onto the iris right before ZM4.  We're thinking of doing the following to finish the alignment process:

• Walk the alignment a bit more to get to the beam diverter and onto the 1064 trans PD on SQZT7
• Optimize the alignment of the seed to the VOPO using the PD
• Dither lock the seed and finish aligning the SQZ path on HAM 7 with the brighter beam.  We will need to revert the FC1 alignment at some point.  Initial settings before we started tweaking things:  
  • H1:SUS-FC1_M1_OPTICALIGN_Y_OFFSET = - 153
  • H1:SUS-FC1_M1_OPTICALIGN_P_OFFSET = 232 

Betsy, Rahul

We found that SUS JM1 had a faulty quadrupus cable, which we replaced it today. Next, I took OLC for both JM1 and JM3 in HAM1 chamber. I applied the offsets, gains and then centered the BOSEMs - and they look good. Next, I will start checking the health of the electronics chain and the suspension itself (i.e. by taking the transfer function measurements).

The offsets and gain for JM1 is recorded in this screenshot - accepted in the SDF (safe).

The offsets and gain for JM3 is recorded in this screenshot - accepted in the SDF (safe).

For the upcoming ISS array swap, we plan to bypass the IMC, which is known to be a pain, but we need a stable beam for the array alignment.

Once the corner volume is vent, we use the QPD on the old array and IMC-IM4_TRANS as the initial reference for bypassing the IMC. Once IMC is bypassed, we will center REFL WFS BEFORE removing the old array and record the RM1/RM2 PIT and YAW. This way, even if we somehow suspect e.g. the pointing of the beam going to the IM4 moved after removing the old array, we can still restore the pointing by looking at the REFL WFSs in addition to IM4.

We measured the beam positions on these QPDs today even though we'll repeat this later.

IFO configuration:

• IMC was locked with 2W.
• REFL beam diverter was closed so no light comes out. (POP bdv was also closed just because.) 
• The cover on the REFL septum window was removed.
• PRM, all IMs and RMs are aligned. (Watchdog of RMs were reset.) ITMs are misaligned.

Arrow ("->") means before and after the REFL centering servo (DC1 and DC2) was turned ON:

Septum cover is left OFF but the PSL light pipe was closed after this. REFL centering was turned off but I didn't bother to offload the ASC output to RM sliders.

REFL WFS nubmers as of now are not super meaningful as we'll still have to lock HAM2 down, which potentially change the relative alignment between HAM1 and HAM2. (But it's good that the beam is still hitting REFL WFSs after HAM1 was locked down even though Jim noted that the ISI position of HAM1 is not good. )

I'll open the light pipe tomorrow and quickly repeat the measurement after Jim locks down HAM2 HEPI.

Closes FAMIS 27648, last checked in alog 88314

Trends look fine!

Betsy, Fil, Rahul

Today we kicked started the installation activities in HAM1 chamber for the Jitter Attenuation Cavity (JAC). Given below are the things we placed on the ISI table - they are all roughly positioned and dog clamped. 

1. Tip Tilt JM1 - now connected to electronics chain, having some issues with the bosem adc counts etc, will continue looking into it.

2. Tip Tilt JM3 - now connected to the electronics chain, bosem centered, will proceed for health checks once the chassis and electronics chain looks okay.

3. The two periscopes for the JAC, Type 121 and 132 - assembly report posted by Jennie - 88574.

4. Some optics on Siskiyou mount were also added to the table.

I am attaching pictures which shows the above mentioned things added to the table - and for comparison a picture showing before any addition was (here) made.

Fil also performed group loop checks on JM1 and JM3 and did not find any issues with them.

[Jason, Betsy, Masayuki]

Two arises are installed into HAM1 chamber. They will be used as the alignment reference for new PSL modematching lens installation.

• Assembled a Thorlabs ID12 iris mounted on a 0.5-inch post with a post holder and BA2 base.
• The assembled iris was temporarily placed inside the chamber and secured with a dog clamp.
• Transitioned to laser hazard.
• Performed rough alignment using a sensor card, followed by fine alignment with an IR viewer, to center the beam through the iris.
• The beam path is offset by ~+5 mm in the +y direction from the ISI design center; this is not considered a significant issue.
• The iris location is marked with a blue circle in the attached figure.

Next step: move to the PSL and install the new mode-matching lens, likely tomorrow. This will break the IMC mode matching; IMC relocking will not be possible until the JAC installation is completed.

(Jordan, Travis, Gerardo)

The relay tube connecting HAM5 and HAM7 was removed.  We had a few snags while removing it, for some reason the space between bellows is tight, perhaps due to the difference between pressure states, one chamber is under vacuum the other is not.

After the tube was out, the viewport was installed on a short assembly, the viewport and the entire assembly was leak checked and no leaks were found.  He background a the leak detector remained at 1.0x10^-10 torr*l/sec during the leak testing.

System is currently being pumped down via a small turbo plus an aux cart.

[Eric, Daniel, Karmeng]

We transferred the OPO from LVEA to optics lab, uncovered the lids and everything looks good.

Touch the mirror mounts and mirrors, no failure except for M3, which swivels off the mount, only part of the glue holding the mirror on the mount.

TITLE: 12/04 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

After CDS & H1-Locking work of yesterday, today we transitioned to starting prep work for the upcoming vent of HAM7.

However, there was more CDS work today which was related to ISC Slow Controls....but in the middle of this...

There was a 90min power outage on site!!
 

LOG:

• early-1615 Randy was at the FCES putting stickers on items
• 1539-1900 pre-vent technical cleaning begins (kim.nellie)
  • 1716 SR3 + HAM5 tripped; gave it some time, untripped/redamped @1805
• 1545 SEI_ENV transitioned to MAINTENANCE for vent
• 1609 TCSx Laser off (TJ contacted; prob due to cleaning near the rack)
• 1624-1745 BSC2 platform & then sorting parts (randy)
  • Tripped BS, ISI, HEPI---leaving tripped until randy finishes in about an hr
  • Once he was done, BS was taken to ALIGNED & SEI_BS taken to DAMPED_HEPI_OFFLINE
  • 1745-1845 Sorting through rail parts in North Bay
• 1626 quick assistance for cleaning (chris)
• 1628-1635 lvea walkthru (richard)
• 1630 cer to pull slow control chassis for ISC (fil)
  • This affects a PZT for the IMC, so it lost lock.  Keeping IMC_LOCK at OFFLINE during this beckhoff work.
• 1718-1810 Unboxing the JAC in the optics lab (jennie, jason)
• 1728 Taking Integrating sphere (had been at KAGRA) into PCal Lab (tony)
• 1730-1855 Grabbing parts at offsite vendor (mitch)
• 1751-1900 Building 2nd CHETA enclsure in the CHETA/JAC Lab (matt)   
• 1803-2012 OPO Testing cont (KarMeng.Eric)
  • 1812 Shiela joining but will be in/out with them + looking for parts
• 1813-1820 chamber measurements for JAC (jason)
• 1814 Kobelco (purge air compressor) being turned on (travis,jordan)
• 1848-2000 Inventory work at EX + EY (randy)
• 2005 Grabbing wipes in Cleaning Room (ibrahim)
• 2023 CHETA Viewport part search (gerardo)
• 2025 Power Outage ON Site!
  • Ended up down for over 90min
• See oli's alog for a summary of recovery.

[Joan-Rene Merou, Alicia Calafat, Sheila Dwyer, Jenne Driggers]

We have entered the LVEA and went to the Beer garden. There, we first turned off the Low Voltage ITM ESD Driver D1600092, first the 15V switch and then the medium voltage switch. In order to turn it on again, it should be reconnected in the opposite order. With the voltage request set to 0 and chassis powered off, we have unplugged the SHV cables going to the chamber and plugged into Robert's ground boxes, which we used to ground to the rack which is grounded to the chamber. This has been done at both drivers (See attached photos).

Afterwards, we have changed the code at /opt/rtcds/userapps/release/isc/h1/guardian/ISC_LOCK.py in order that the LOWNOISE_COIL_DRIVERS will go to LOWNOISE_ESD_ETMY instead of TRANSITION_FROM_ETMX. This has been done by changing lines 6670 and 6674, moving the ", 15" step from line 6670 to 6674. Finally, we communicated the change to the operator and loaded the guardian.

Related: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=87729

We disconnected everything from the ISS array installation spare unit S1202965 and stored it in the ISS array cabinet in the vac prep area next to the OSB optics lab. See the first 8 pictures.

The  incomplete spare ISS array assy originally removed from LLO HAM2 (S1202966) was moved to a shelf under the work table right next to the clean loom in the optics lab (see the 9th picture). Note that one PD was pulled from that and was transplanted to our installation spare S1202965.

Metadata for both 2965 and 2966 were updated.

ISS second array parts inventory https://dcc.ligo.org/E2500191 is being updated.