Laser Status:
Front End Power is 33.75W (should be around 30 W)
70W Output Power is 71.1W
Front End Watch is RED
70W Watch is GREEN

PMC:
It has been locked 0 days, 0 hr 9 minutes (should be days/weeks)
Reflected power = 10.57Watts
Transmitted power = 58.87Watts
PowerSum = 69.43Watts.

FSS:
It has been locked for 0 days 0 hr and 0 min (should be days/weeks)
TPD[V] = 0.05622V (min 0.9V)

ISS:
The diffracted power is around 0.15%
Last saturation event was 0 days 0 hours and 14 minutes ago (should be days/weeks)

Possible Issues:

Vent activities/PSL table work are the dominating feature in all plots this week, folks.

LVEA is LASER HAZARD - light pipe is currently CLOSED

HAM1 closeout tasks: Ground loop checks; measurements; labeling of L4C cables

HAM6 - TF's currently running          

We connected the 5-way coax to TNC adapter that Fil has made to the chamber. 5-way coax cable assignment is in D1300466.

We measured the TF from cable 2 to cable 4 while cable 5 was terminated (attachment 1), then from cable 2 to cable 4 while cable 4 was terminated (attachment 2) and both made sense.

The problem of this configuration is that shells of TNCs are touching with each other (attachment 3, note that cable 2 and cable 5 are terminated).  We put cable 1, 2, 3 and 5 inside different fingers in a glove to insulate things from each other (attachment 4).

For the moment 9MHz connector is exposed but it's not touching any surrounding metals.

For a short while we locked MC with 200mW and measured the coherence between REFL_A and REFL_B 9MHz, and it also made sense (see Georgia's comments).

TITLE: 11/19 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 3mph Gusts, 1mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.16 μm/s
QUICK SUMMARY:

Keita and Georgia working on REFL PD in HAM1

• 16:10 they are finished wih the beam and have closed the shutter

The last 24 hours of pre-modecleaner output is plotted.  The long stretch at the end of the plot is when alignment
work was finished yesterday.  The uptick at the end is an alignment tweak at the end.  The power drop due to the
alignment drift is ~0.5 W.  Most of the correction was in the horizontal plane.

Terry, TVo, Dan Brown

Today we tried to align the squeezer seed and PSL beams to the OMC to do some mode matching tests. The seed beam was far too weak to achieve anything in the end though.

Initially we aligned the squeezer beam to AS A, AS B, and the OMC QPDs by steering the beam with ZM1 and ZM2. This required some significant adjustments to the slider values, old and new values in picture attached. The sum on AS A and B maxed out about 8 counts. With the seed beam diverted we then aligned the IMC and did a single bounce from ITMX with the AS alignment loops closed. We then switched off the loops and unlocked the IMC, letting the integrators keep the alignment fixed towards the OMC.

We then realigned the seed using ZM1 and ZM2 again to center on all the QPDs for a SRM single bounce - the seed beam should be roughly aligned with the single bounce beam from ITMX now. However, when misaligning SRM and doing an ITMX single bounce the seed beam was no where to be seen. With SRM and ITMX aligned we could see misalignment fringes drifting over the seed beam on AS air camera, so the alignment couldn't of been that far off. We tried to align ITMX and SRM better to remove any misalignment fringes for the PSL beam and redid the zeroing of the see alignment on the QPDs, but we still couldn't see anything. No sign of the ITMX single bounce seed beam when doing an OMC can either.

Given we saw 8 counts with SRM single bounce we would expect to see about 0.25 counts off of the ITMX. We probably need an order of magnitude more seed power to see much. Terry seems cautiously optimistic we could achieve this, he thinks we have about 100uW of seed coming out of the OPO currently.

We also wanted to try and see how the astigmatism of the SRM single bounce beam depended on alignment. However the OMC scans weren't clean enough to resolve the astigmatic 2nd order peak due to being in air, so that will have to wait.

The ZM1 change has also shifted the beam on the SQZT6 camera position when closing the beam diverter.

We left the PSL shutter closed and turned the purge air back up in HAM6.

PeterK, RickS

Jason tweaked the alignment into the 70-W amp a bit late Friday afternoon.  It seemed that the pedestal in the 70-W output beam had been reduced and the beam didn't look too bad.

Today, we aligned into the PMC, adjusted the modematching lenses, adjusted the 70-W diode temperatures, and adjusted the pump currents.

We now have about 60 W (59.9 W) in transmission with about 10 W (9.7 W) reflected from the PMC.  This is about 86% visibility using the power monitors.  The visibility measured with the DC out of the RFPD (using the no-light level when the PD is blocked, about 14 mV) is (238-26)/238 = 89% (see attached scope image).  An improvement over what we had last week.

The ~60 W in transmission is close to what we need for O3.

The FSS is locked, but the ISS AOM is still removed from the beam path so the ISS is inoperable.

Purge air and turbo stations all running well.

EY & vertex pressure trends attached.

Sheila, Terry, Haocun, Daniel, Nutsinee

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Summary: Dichroic flipped, measured some red losses (roughly 96% transmission from first dichroic to the bottom periscope on SQZT6), fixed the polarization issue (rotated in-vac half-waveplate by 7deg), aligned pump to OPO better (91% mode matched), and measured some distances from OM3 to AS_A and B. Ready for closeout ceremony

------------------------------------------------------------------------------------------------

Details:

Dichroic flipped and red losses

We flipped the first dichroic BS that was mounted backward (alog45288) and corrected the beam translation with the first and second dichroic steering. That went well. After that we locked the OPO on duel resonance at non-nlg temperature (51.2C), then measured red power just after the first dichroic and just before the bottom periscope on SQZT6. We took two sets of measurement:

Each measurement has +-3uW uncertainty. Note that before we still have green reflected after the first dichroic we had to block seed and measured green so we can subtracted that out from the transmission calculation. Green didn't make it all the way to the periscope. We just took the average of the two transmission measurements and called it 95.7%

Fixed Polarization Issue

For quite some time we were not able to get rid of the wrong polarization of the OPO refl (green) with just a half waveplate and the beam splitter cube on the SQZT6 alone but was able to get it down to <1% with a combination of half and quarter (alog43443). So we concluded that whatever came out of the vacuum was not linearly polarized. We turned the in-vac half waveplate by 7 deg and that solved the problem. I think the wrong polarization is now <1% of the total reflected power when OPO is unlocked, it jumped up by ~50% (of the OPO unlocked, wrong polarization power) when the cavity is locked. I'll have to get these number later. But it's all better that it used to be.

Pump alignment

Better than ever. The new fiber works so far. The data here has been darknoise subtracted. 88% total mode matched (all visible peaks taken into account) with the misalignment (10 mode) being just 4% of the 00. The forth peak on the far right (0.04) is likely mode mismatched and I'm not sure what 0.024 was, higher order mode wrapped around? The 80MHz modulation was unplugged when the scan was taken so there's no sidebands here. The wrong polarization peak exists between the 3rd and the 4th peak and it's ~1% of the 00 mode (visible when you zoom way in on StripTool, barely visible here). We only knew it's there because the Hansch-coullaud locking signal was visible on the OPO refl rejected.

OM3 to AS_A, B distances

Here I posted the number I was given as Haocun and Sheila did the measurement. Yes it's a mix of inches and mm. I'll let the conversion up to the user.

Still need to dump the close-out photos from the SD card. Will post that later.

K. Kawabe, J. Kissel, G. Mansell, D. Sigg

We've achieved the following in HAM1 today:
    - Measured beam profile on LSC side (reflection side) of LSC/ASC REFL Beam Splitter (M6 on D1000313) down stream of the lens L1 (without LSC REFL A or LSC REFL B, or LSC A/B beam splitter in place)

    - Re-installed LSC REFL A/B beam splitter, and LSC REFL A PD 

    - Installed new LSC REFL B PD

    - Aligned beams on to LSC REFL A and B using LSC/ASC beam splitter, LSC A/B beam splitter

    - Aligned LSC REFL A and B PD such that their reflections are dumped appropriately

    - Verified the distances between LSC A/B beam splitter and each PD which we believe will result in a beam radius of ~240 um (details to be posted later)

    - WFS B beam dump black glass** has been replaced, as discussed in LHO aLOG 45279

    - We found that physical ASC REFL B was read out in the digital system as ASC REFL A (both DC and RF), and vice versa

    - Attempted to figure out what was wrong with ASC REFL A segment 4 DC, tried many things including various cable swaps, ended up reverting to the original configuration as we found it. DB25 for physical ASC REFL B (digital ASC REFL A) was not secured at all. This was reseated and secured. This somehow repaired the faulty segment, but we can't really identify exactly what fixed it.

    - We measured the laser power at various points in HAM1 with a dodgy OPHIR power meter:
        IMC_PWR_IN reports 250 mW.

        Inside HAM1, that same input beam as it flies through HAM1: 234 mW
        IFO REFL beam coming back into HAM1: 227 +/- 50 mW
        REFL AIR path: 4.1 +/- 0.5 mW
        In front of LSC REFL A: 1 +/- 0.5 mW
        In front of LSC REFL B: 0.87 +/- 0.5 mW

        LSC-REFL_A_LF_OUT16 reports 0.8 +/- 0.01 mW
        LSC-REFL_A_LF_OUT16 reports 0.735 +/- 0.01 mW

    - We checked all new components for being bolted to the table, and we cleared the table of all tools we used today.

**The existing black glass stock all appear to have water marks of some sort, so Keita took the best he could find, and used a pre-soaked wipe to clean off what fogginess he found.

We have left the IFO with both the main PSL input light pipe and the ALS light pipe shuttered.

What's left to be done:
- Verify that LSC REFL A and B's RF signals are functional (we only verified that DC signals are functional). Currently the cable that connects the TNC to 5-way coax piece is missing at the chamber feedthrough.
- The chamber-closeout ground loop check

Detailed blow-by-blow log is attached. Also attached are some relevant screen captures of the state of things after we'd finished with the IMC locked on 250 mW input power, the IMs, RMs, and PRM aligned, and with the REFL DC centering loops engaged.



Pictures, and plot of LSC REFL path beam radius evolution to come in a bit.

Danny V., Dan Brown, TVo

During one of the lock losses last week, we paused the CO2 compensation on both ITMs in order to get an absorption measurement with just IFO cooling.  Also during this time, Dan did some post processing on the Hartmann data in order to better fit the spherical power to the wavefront distortion. Previously, the HWS code provided did not take into account for an offset in the IFO beam relative to the center of the Hartmann camera and Dan was able to add the ability to re-fit using the IFO beam as the center and this has cleaned up our data a lot.  With this new data we use the exponential decay from a COMSOL model from this  ALOG-14634 and provides a pretty good fit for both ITMs ( Figure 1 and 2), the largest uncertainty is estimated by varying the starting time for our fits from when the lock loss actually occurred because the optics swinging around caused a lot of noise in the Hartmann sensor.  It should be noted that we haven't subtracted any point absorbers from the ITMY data which will over-estimate the amount of ring heater compensation, this means that we could have some CO2 left over at 50 watts for CO2Y. 

ITMX absorption: 304 +/- 38 ppb

ITMY absorption: 804+/- 42 ppb

Figure 3 and 4 provide the pre-loading settings estimates for 50 Watts using this absorption data and some actuator calibrated numbers which we fine-tuned during this quiet vent break (while the corner is under vacuum but HAM1&6 are open) , interestingly, the amount of spherical power for ITMX-CO2 differs ITMY-CO2 by a factor of two according to the HWSs, we're still trying to track this down. 

Parameters used to work out the TCS settings for O3 (diopters/watt):

#factor of 2 for the double pass
RH_SUBdef = -2*9e-6

#factor of 2 for the double pass
ITMX_CO2_SUBdef = 2*1.5e-5
ITMY_CO2_SUBdef = 2*2.5e-5

SelfSUBdef = 4.87e-4

# Parameters for surface deformation 
RH_SURFdef = 9.91e-7
SelfSURFdef = -3.60e-5

Calculated O3 Actuator:

ITMX:

Self Lensing is 41.2594 uDiopters
Required RH Lensing is -0.0 uDiopters
RH Power required is 1.1811 Watts
CO2 Lensing required 42.9709 uDiopters
CO2 Power required 1.4324 Watts

ITMY:

Self Lensing is 101.4137 uDiopters
Required RH Lensing is -100.0 uDiopters
RH Power required is 4.523 Watts
CO2 Lensing required 100.4321 uDiopters
CO2 Power required 2.0086 Watts

We can dial in the CO2 laser power now and when we have reached the Paschen limit, we will turn on the ring heaters and use the HWS to track the wavefront through this process.

After quick peeks at the TFs at closeout yesterday showed healthy suspensions, the door to the chamber was closed and pump downs started.  Today, Travis and I ran the full set of Transfer functions for ETMY MAIN, REACTION, and TMSY suspensions (18 measurements).  All plots look good and can be found at 2018-11-14* Files in the appropriate directories.  Between Travis and I, we're a few hours into this today (running, exporting, troubleshooting matlab, etc) and I need to move on to other things, so pretty plots aren't going to be posted today, especially without the auto-renumbering scrip at my fingertips for the master plotting script.  See the files if you want to look at them yourself although I still need to commit them to the svn.