Keita, Cheryl, Jenne, TVo

- After getting the beam onto HAM6, Keita suggested optimizing the beam position on SR2 and SR3.  The difficulty with trying to use the cameras to align the beam to the center of SR2 is the key hole scraper baffle makes it difficult to figure out which beam (input or reflection) you're actually seeing scatter off the edges.  Not only that, the bright spots that we do see scatter don't seem to move linearly with SR3 pitch/yaw, this is very odd.

- Cheryl found a good pointing of BS and PR3 to center on SR3, but that changes the input beam into the Michelson. Also, by changing the SR2 alignment, she was able to sweep the SRM reflection across SR2.

- I found a better alignment through the Faraday that gives us approximately 10 mW single bounce onto AS_C (somewhat calibrated?), which approximately matches our back of the envelope power budget with input power of 5.9 Watts from the PSL, by sweeping SRM around, I was able to get a small SRCX and SRCY flash.

Rough plan for tomorrow:

Somehow we have to make the three points above converge to a decently aligned DRMI.

Since we've already done a lot of work aligning PRC and Mich in the past week or so, it might be worth it to preserve the PRC alignment by walking the beam around SR3 to find its center point.  This could possibly be done by changing the beamsplitter and ITM alignments to sweep the face of SR3, while maintain the LSC_POP relatively steady in value.  Mich will be flashing so it might be a little tedious to tell if you're improving but it's doable.  

At the same time, since we've got a AS_C signal, we can try to maintain a signal by changing SR3+SR2 alignment, so we don't have to try to find the beam when going into HAM6.

Then, per Keita's suggestion, we can enter HAM6 sweep around the combination of SR3 and SR2 pointing so that we find the edges of the baffles+Faraday and find the middle of the clipping, this might be as good as we can get with SR2 centering.

J. Kissel, M. Pirello

After SUS'ing out the OMs and the OFI, and while still trouble shooting ZM2, I wanted to post redlines to D1002876-v4 which hasn't been updated to include new squeezer suspensions. Granted, we still haven't confirmed ZM2's functionality (see LHO aLOG 40207).

Continued with field cabling in the LVEA.

1. Illuminator cables for HAM4/HAM5/HAM6 were terminated and connected to chassis power. This completes illuminator cabling for the corner station. New modules need to be added/scanned to beckhoff to control on/off functionality.
2. Ran cables for VOPO and ZM1 from field rack to top of HAM 6.
3. Ran cables for TCS SR3 Heater (CER to HAM5).

F. Clara, E. Merilh

TITLE: 01/22 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
LOG:
 

17:45 Sheila to  optics lab

18:15 Ed to output arm, terminating cables

18:15 Kyle to MY

18:30 Peter & Gerardo to optics lab

18:30 Travis & Danny to EY, back 20:30

18:45 Jason to EY

19:00 TJ to optics lab

19:30 Marc to LVEA

19:30 Cheryl to IOT2

19:30 JeffB to ITMX camera, back 20:30

21:30 Welding crew to EY

21:30 Marc to HAM5 done 22:15

22:00 JeffK to HAM5 done 22:15

22:00 Kyle to LVEA

22:00 JeffB to ITMX camera

22:15 Corey to optics lab

22:15 Nutsinee to sqz

22:45 Tvo to HAM4

[Kyle, Chandra]

Note:  this activity caused expected Y-arm pressure alarms.

Verified we have an outer o-ring leak on GV-11 gate that needs to be addressed before CP4 bake. We back filled the gate annulus with dry N2 and allowed pressure to rise for 7 minutes to see if it would flatten out (it did not as it approached 1e-7 Torr). Once we're back on its AIP, we will re-seat the gate and retest. If that doesn't fix the o-ring we will install a valve at the 1-1/3" gate port so we have the ability to pump on it during bake. If need be, we can soft close GV-10 (which will isolate mid-Y's large ion pump from Y1 arm) and valve in the small ion pump attached to CP1.

Then we repeat for GV-12.

[Keita, Gerardo, Jenne, Cheryl]

With the new input alignment from after the vent, we checked the PRM's parking spot and have found the misaligned location that puts the beam on the steering mirror above the viewport above HAM2.  Keita made some small adjustments on that steering mirror to center the beam on the beam dump.

This was WP 7305.  It turns out there is no insert for a lexan cover, but Gerardo had (from a previous time doing this) a thick piece of plexiglass that was cut to size to fit over the viewport while these checks and adjustments were made.  The plexiglass was removed, and the cover reinstalled.

Laser Status:
SysStat is good
Front End Power is 35.34W (should be around 30 W)
HPO Output Power is 140.9W
Front End Watch is GRE
HPO Watch is GREEN

PMC:
It has been locked 3 days, 23 h/weeks)
Reflected power = 28.09Watts
Transmitted power = 38.88Watts
PowerSum = 66.97Watts.

FSS:
It has been locked for 3 days 21 TPD[V] = 1.627V (min 0.9V)

ISS:
The diffracted power is around 2.8% (s
Last saturation event was 3 days 21o (should be days/weeks)

Possible Issues:
PMC reflected power is high

Plots show the last two trips. All  other plots look normal.

Last week we added the OPO and some of the optics to the VIP.  

• Fil and TJ got the lens translation stage connected to the DB15 connector for the DC diodes.  
• Fil also made us a pigtail cable that we can use to drive the piezos through our class B  pin D sub.  
• We placed the thin film polarizers for cleaning up the polarization for both the IR (CLF) and green pump paths.  We adjusted their angles to maximize transmission. 
• For IR, we placed a diode on the reflected beam (off the platform), and we were able to add one for the transmitted beam using the leakage beam.  
• For green, we have placed a third diode for the reflection, and should be able to use the CLF reflected diode to measure transmission. 
• While we have the beams roughly aligned, our alignment is not yet good enough to see cavity flashes.  

[Sheila, Terry, TVo, Jenne]

Beam go through hole, all the way to HAM6!

Attached are 3 screenshots, with titles indicating what they mean.  The important one is the last, BeamOn_AS_C.png, which is the slider locations where we see some beam on AS_C.  That means that we're making it through the output Faraday!

(The 2nd screenshot is where we think we're roughly centered through the OFI).

In Friday, Travis finished cleaning up the ETMY PUM horns by filing them to the proper length and then cleaning up the debris in the flats. I then thoroughly cleaned the lower main structure using a tiger vacuum and wipes. Gerardo aided us in weighing the new ETM test mass (ETM16) and installing it in the structure using the ergo arm.

Jason also worked on setting up IAS equipment to look at the suspension in the afternoon. His equipment is parked in the far side of the weld cleanroom away from the man-door entrance into the VEA and he has caution tape around some of it. Please limit activities around this equipment and watch your step near it if you need to get to the other side. We anticipate the equipment to be removed after next week.

We are in good shape to start the fiber welding process on this suspension next week.

Jenne, Sheila, TVo

We spent most of Friday using cameras to get the pointing of SR3 onto SR2 and back down to SRM correctly but it was much more difficult without a sensor to tell if you're actually getting the center of the baffle aperture.  We think we were able to eventually get the right beam down to the SRM but it's not obvious how well centered you are on any of the optics (except SR3 since we have the input chain well aligned).   We were hoping to get the optics close enough so that an excitation on all three optics would show up all the way back at LSC-POP but unfortunately this didn't work.

The next hopeful resolution is to get into HAM6 and try to align through the Faraday with an IR card.

J. Kissel, M. Pirello

After finishing out the OFI, I moved on to H1SUSZM2. It doesn't yet work.

Symptoms:
- The OSEM sensor readbacks (the ADC inputs on the MEDM screen) are showing little-to-no signal (only ~1000 cts), however transfer functions still have plenty of coherence.
- Although ZM2 is driven with an ISC configuration HAM-A driver, which supposedly has all binary control jumpered such that the low-pass filter is engaged, the pitch and yaw transfer functions show excess response at high frequency, which can be "calibrated out" by using exactly the same poles and zeros as the low pass filter (zpk(zeros,poles,gain,normalization) = zpk([0.9;211.883],[10;21],1,"n")). So it's as though the filter *has not* been jumpered. However, because there's plenty of coherence with the TFs, the Test/Coil enable jumper must be good.
- In a quiescent state (damping loops OFF, but no excitation), the BOSEMs ASD shows noise elevated way above the noise floor.
- Earlier in the day, when the external OFI's signal chain was unknowingly hooked up to the ZM2 in-vacuum chain, we saw lots of signal (i.e. the typical ~15000 cts), and transfer functions showed a normal frequency response (except for the poor basis conversion; see MAGENTA comments below).

Attached are 
- Transfer Functions. BLACK is an old OM1 result, RED is as it stands now, MAGENTA is driven and readout with the OFI chain. Regarding MAGENTA -- Unfortunately, when driving a 4-OSEM tip tilt through the 3 OSEM OFI chain with the wrong coordinate transformation matrices means that all three "long" "pitch" and "yaw" drives were some wonky combination of only UL, LL, and UR. That's why you see a poorly diagonalized result, and you see all three DOF's modes in each TF.
- Some MEDM screen shots relevant to the discussion
- The DTT and Foton comparison for the "calibration" of the Pitch and Yaw TFs. Note, the TFs are *not* shown with the calibration, but trust me, when it's applied it makes the high frequency response of the RED match BLACK
- The OSEMs ASD compared against the target / spec BOSEM noise.

Because of the incorrect frequency response, I suspect the coil driver either hasn't been jumpered or it's just a bad board. Note, also, as is standard on the HAM-A driver, US field sat-amp systems, the sensor signals are plugged directly from the sat-amp into the AA chassis towards the ADC / IO chassis. That means that the sensor signals, which are polluted with noise are *not* being polluted by the coil driver. So maybe both are problematic?
We know the in-vac suspension and electronics are OK, because they tested well with the OFI signal chain.

We'll investigate further on Monday.

Sheila, Nutsinee

Here I attached the SHG conversion efficiency measurement as a function of 1064 input power (red dots) plotted against theoretical prediction (the equation came from Polzik and Kimble 1991 paper on frequency doubling) . ~75% conversion efficiency at 400mW input, 48% conversion efficiency at 100mW input. For the fit I tweaked a couple parameters, intracavity losses (L) and the single-pass nonlinear conversion efficiency (Enl).

Here's everything I wrote down.

The common mode board common path gain was adjusted to keep the UGF at 3kHz.

The responsivity was adjusted to match the photodiode readback to the power meter.

P in and P out was measured with a 1W Thorlabs power meter. P trans was read out of the photodiode.

The optimized crystal temperature for green output was the same for all input power, at 35.9 C

[Kyle, Chandra]

We leak checked the gate of this valve after suspecting a leak. Kyle cycled it five times on leak detector and four out of the five times it leaked (e-6 mbar-L/s range leak). Then we sprayed the gate with IPA to clean it and re-tested with three cycles. No more leaks! It could be that particulate fell on the gate gasket during rough down when it was installed on OMC NEG housing. 

We have since received six more of this valve model and decided to leak check all at once right out of packaging. All six are leak tight to a level of 5e-8 mbar-L/s background. I cycled each valve once while on leak detector.

https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=9593