1. PMC monitor PD was T-ed and connected to PSL spare 7 cable.

Since bogus power reporting of PMC transmission monitor has bothered us more than once (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9300), and since this might be an oscillation of the PD electronics, we T-ed the output of the PD and connected it to "spare 7" cable which goes out to the PSL rack outside.

I connected the cable to Ch.4 of the scope in PSL R2 rack.

When the power (H1:PSL-PWR_PMC_TRANS_OUTPUT) is reported 11.2W, the PD output was measured to be 715mV DC on the scope, with AC RMS of 1.74mV without any noticable oscillation (attached is the scope screen with AC coupling).  Next time it is reporting bogus power you should go to the rack and see how it looks.

2. IO Kentec beam dump

We have found two IO Ketek beam dumps, both 0.75" aperture variety (ABD-3/4), in the cabinet in the PSL ante room. We took one that is to be installed in the HAM2 ceiling viewport in preparation of the 10W operation.

This beam dump is to replace a black glass that is in place now. Ultimately Kentek will be replaced by the final solution once it is manufactured.

We will NOT remove Lexan cover for this viewport until approved by John Worden.

A bigger Kentek (2" aperture, ABD-2) was already installed in IOT2L some time ago. This will be left in place as it's considerably bigger than 0.75" one and thus will run cooler. The final solution will come later than the HAM2 ceiling one, but it will come at some stage.

Mitchell & I departed the LVEA ~1650pst

With the model changes Hugo did for the ISI we were able to confirm all the sensors we have installed.  Haven't run Spectra but the look reasonable for now.  We dressed & secured cables, installed cable brackets and took a stab a preliminary balancing.

To do--Install Table extension (Or should we test w & w/o?)

Fine tune balance, float HEPI & level locked ISI--it already is pretty close, only 27mils tilt across the table.  Revisit balance, maybe adjust lockers.

Validate ISI.

IAS

We are investigating startup problems observed with the HWWD units under test. As part of the testing we power cycled the unit in the CER twice this afternoon. This unit is monitoring ITMY only.

Attached below are power spectra of ETMX main chain OSEM and optical lever signals from Monday January 13, 2014 through Thursday January 16, 2014. The magnitude of all signals has decreased by about a factor of 100 since Monday.

On the PUM stage of the ETMX, the upper left OSEM is noisier than its counterparts as can be seen from the ambient noise figures. It's possible that this OSEM signal is not being correctly filtered, or there may be a problem with the OSEM itself (cabling, led, or photodiode, etc). This isn't a huge problem that we have to fix but is worth noting while we are undergoing ER5. Also attached is a coherence plot between L2 stage OSEMs and optical lever pitch and yaw. The sensors are highly coherent near the suspension resonance peaks, but are pretty incoherent after about 2.5 Hz. The problematic upper left OSEM is less coherent with optical lever pitch and yaw, which again suggests that this sensor has some electronic issue.

:::  EX is Laser HAZARD  :::  LVEA is Laser SAFE  :::  EY is Laser SAFE  ::

EY:  Travis doing Welding clean-up & possible Quad work (probably most of the day)

Dust:  Dust #9:  Calibrate failure (notified Patrick)

PSL:  Went through PSL Checklist.  Have a "check diode chiller" WARNING & sent an email to the PSL group email.  Doug filled it up around 11:30am

Day's General Activities:

• Before 8am:  Balers continue:  at LVEA, may continue with X-arm
• 8:30-1000:  EX Dressing of ISC cables (Filbertro/Aaron)
• 8:50-9:30:  Jeff/Andres in LVEA looking for stuff
• 10:05:  Joe D (& possibly Chris S & Rick S) working in H2 PSL room on Periscope Assy
• 10:10-10:50:  Andres working on SR Suspension
• 10:15:  Apollo scoping out Nitrogen piping
• 10:20-11:30:  EY RF ISC cabling (Filiberto/Aaron)
• 10:25:  Adjust ADC Channel Numbers feds to HAM4/5 models (Hugo)
• 11:20:  Praxair filling CP6 (MX)
• 1:18 - 1:51:  Call for 100Area Take Cover Drill
• Afternoon:  Apollo removing piping under the H2 Output
• 1:30:  HAM4 work:  connecting/check out sensors, balancing, cable dressing, etc. (Hugh, Mitch)
• 1:45:  Jeff/Andres searching for SUS tooling at LVEA, EX, EY
• 1:58-3:12:  Powering Seismometer (Filiberto)
• 3-4pm:  Rick & Keita searching for beam dump in H1 PSL

We reattached the ETMy upper structure to the ISI on the cartridge test stand this afternoon.  We have a few more dog clamps to attach but can do those anytime.  SEI can get to work there tomorrow if they see fit.  We'll work elsewhere.

Kiwamu with remote help from Cheryl

As a part of the high power prep, I did three things this morning:

• Scan with an IR viewer to make sure there is no stray light on IOT2L and ISCT1.
• Power budget of IOT2L and ISCT1 to check the power level at various place.
• Attempt to search for the PRM parking beam.

Stray light:

I looked around the inside of the IOT2L and ISCT1 enclosures with an IR viewer to look for a stray light which needs to be properly dumped. I did not find a stray beam and therefore I didn't have to newly install a dump.

Power budget:

See the attached. When I made the measurement on IOT2L, I intentionally misaligned MC2 in order to have high and stable laser power on the IOT2L. As for ISCT1, I misaligned PR2 to avoid a fringe while maintaining the PRM reflection. Note that the IMC incident has been 1 W (see alog 9306) these days and during these measurements. Because the POP beam was so dark, I didn't even attempt to measure the power. Instead, I made a back-of-envelope estimation of the maximum power in the POP path with an assumption that the power recycled Michelson is locked.

Power at POPAIR_A (or POPAIR_B) = (1 W incident on PRM ) x (60 power recycling gain)  x (250 ppm PR2's transmissivity) x (90% BS in HAM1)  x (50% BS on ISCT1) = 6.75 mW

Of course, in reality, it must be smaller than this due to losses and etc.

Search for PRM parking beam:

Because we didn't check the parking beam during the last vent and also readjusted the alignment of the input optics recently, we need to find a good alignment for PRM again which gives us a parking beam coming out through the top view port of HAM2. Since a CCD camera was already mounted on the viewport, I used it to see if I can find the beam. I tried the good PRM biases (P=-330 and Y=-6100) that was established back in April (see alog 6168). Also, I enabled AWG and shook PRM in both pitch and yaw in order to somewhat expand the parameter region that I am scanning. However, I didn't find a beam or any sign of beam on the monitor. Also I turned the illuminator on and off to see if the CCD camera is actually looking at something useful, but the CCD kept showing a dark background regardless of the illuminator.

I am concluding that we need to remove the camera canister to see how the camera is doing and directly check the parking beam with a laser card or IR viewer.

Input filters were loaded and installed on HEPI-ITMX yesterday at 12:45pm

Matrices were updated on HEPI-ITMX from the 'X' direction convention to the 'Y' direction convention, yesterday at 12:54pm.

Position loops are not installed on this unit yet. Previous transfer functions were measured in the local basis, before the input filters. Hence, those changes, which were needed, should not impact commissioning activities.

(Corey, Doug, Sheila)

While doing the PSL Checklist today, I noticed that we were getting intermittant "Check Diode Chiller" WARNINGS on the SYSSTAT.adl window.  Sheila and I went to the Diode Room to check.  There's a spout on there with Min/Max lines on it (it was closer to Min, so we topped it off).  Peter King actually mentioned that this is spout is for the Crystal Chiller.

The lower LCD Display still was flashing with "level warnings", and Sheila said it was probably for the lower resevoir which has a big cap (this one is the Diode Chiller). 

I emailed the PSL group and Doug ended up going out to fill the Diode Chiller resevoir at around 11:30am.  He said it took 4 gallons to top it off! 
 

And Operator Note:  He used distilled water (NOT deionized water from lab---because it is corrosive).

(Alexa, Daniel)

With the cavity unlocked, i.e. only the straight-shot green beam, the power at the bottom of the periscope was ~12uW. The power at the green trans PD was ~2uW (after an 80-20 BS).

We also determined that the trans PD cables inside the table to the feedthrough were swapped between X and Y. That has now been fixed.

Attached is a coherence plot.  Basically all X motions on the ISI on the two platforms have similar coherence with their Optical Lever Pitch.  Interesting though, the ITM with a 0.56Hz notch has much broader coherence below this frequency whereas the ETM has no notches and much less coherence elements below 1Hz.  Maybe there is area here to improve.

Starting at 12:01pm.

We connected the following cables in EX:

• ADC readback of DC PD (previosuly only in slow controls)
• ADC readback of the D-sub breakout (used for RT link)
• DAC output to the D-sub breakout (used for RT link)

The RT link is now working and can be used to engage the boost filters for the arm cavity feedback to HEPI/SUS. The PD readbacks of th red path are now in the online system.

Stefan, Kiwamu

We did the following things tonight:

- We measured the BS, PRM and PR2 actuator transfer functions again and convinced ourself that they are not crazy. The BS actuator was found to have the opposite sign and 10 times bigger gain at 20 Hz.

- As a preparation for PRMI locking, we started using RELAIR_A_RF45. We found that it is 5 times smaller than RF9 in terms of the PRX optical gain. We could easily close the PRX/Y loop with RF45_I.

- Because we were not sure if we could close the MICH loop with BS, we went back to PRY to verify the behavior of the BS actuator in action. The idea is to optimize the LSC filters for MICH loop beforehand using PRY.

-We discovered that there was a length to pitch coupling in BS which caused 5-10 urad excursion in its angle. This was big enough to unlock the PRY loop.

- POPAIR_B_RF18 demod phase = 80 deg

Our message is that we need to put some more efforts on the BS actuator.

We used the new prism protection shield on the PUM prisms during the welding of the ETMy monolithic in Dec and again this last week.  We used the shield during the welding steps but not always during the lower power annealing steps, as was assumed by the users.  We think the shield caused more stray beams from the welding laser than when we weld without it.  We found more stray beam damage to curtains and garb than in any previous welding session, all of which we tried to mitigate.  Possibly we could consider making the shield out of a different material than copper.

We also found that one of the prism glue joints suffered some heating, and subsequent charring, at the exterior of the prism when the shield was not in place during annealing.  This occurred on only 1 prism.  The other prism had the shield in place for all of the welding (as is standard) and for the annealing in Jan which is why we didn't see the charring.  (We did not observe any stress fractures in the glass as was seem in the ETMx PUM!)  So, the new shield has the following:

PRO
Prism joint is better isolated from heating/burning during welding.

CON
Shield causes more CO2 beam reflections which are difficult to manage.

Below are some pictures of the shield and the prism charring when the shield was not in place.  Note, we had to cut a half circle view hole on each side of the prism for better visibility of the horn welding.  Also, as shown in the pictures, it was difficult to get the shield positioned against the optic.

ISC length control offload path was added to HEPI-ETMX's model: h1hpietmx.mdl - See attached screenshot of the model.

The model was re-compiled and re-started - log attached.

DAC restart was required and performed by Dave.

Isolation and alignment offsets were turned back on, per the latest preferred configuration, and the ISC2CART matrix was updated. The outputs of the ISCMON block will be left off until ISC decides to try them.

Note: The signal offloaded to HEPI is the same as the one offloaded to SUS.

The new version of h1hpietmx.mdl was commited under the SVN -r6869

Work was performed under work permit # 4394 which is now closed.