Following up on the earlier post 4327 concerning H2 OAT line studies, I am attaching additional slides
containing plots and tables that compare the OAT spectrum from August 28 (focus of last report)
with spectra on Sept 7 (generally quieter with fewer combs) and on Sept 13 when the aLIGO PSL
was being used for the ALS reference. The spectrum on Sept 13 has a higher noise floor, more lines
and stronger lines in many cases. In addition, a number of combs observed on August 28 moved
slightly in fundamental frequency by Sept 7 and moved again by Sept 14. See slides for details.

Looked at MC1 (Bottom stage) UL channel, which showed low counts ~9000 compared to the expected 24,000 counts. Traced problem to IO Chassis (h1sush2a). Replaced ADC card SN110201-04 with SN110203-20. Problem still persisted, replaced ADC Adapter Board (D0902006 SN S1102390) and cabling inside IO chassis with a spare (no SN number). Have requested a replacement from CIT. Will replace sometime next week, but SUS is able to continue transfer functions on MC3.

Filiberto Clara

-SEI Ham1 waiting on hardware.
-SEI HAM3 Float ISI
-Craning doors To HAM1 AND GARBING STAGING ROOMS.
-Ski to change out valves at X-End.
-Cheryl and Rodica working on the PSL doing isolation measurements on the Faraday
-Vincent and Robert reboot NDS0

Doors locked at 16:17:00 PT

Andres R. & Jeff B.

   We released the EQ stops on the MC2 & PR2 Bottom Masses for the weekend. Both Intermediate Masses are still in light stops.  

JimW, MitchR, HugoP,

The horizontal position of the lockers was adjusted.
The 0 of the horizontal CPS was set on the new locked position. 
The shift on the CPS between the locked and unlocked configurations is within +/-600cts on each sensor.

Since this preparatory work just ended, we did not have the time to run a full-range transfer function measurement while attending it. Hence, no actuation will be performed over the weekend.

The ISI was left locked so JeffB could get in and release the optics of MC2 and PR2 before the weekend, as he requested.

We will look at the level of the ISI on Monday. 

Mark B and Jeff B.

After today's electronics and computer issues, we restored settings on MC3 and started running Matlab TFs at around 13:20 PDT. We started with damping on and will repeat with damping off this evening.

Restarted h1seih23, h1sush2a, h1sush2b, and h1sush34 models, due to glitching the dolphin network while troubleshooting a bad ADC channel on h1sush2a.  DID NOT DO ANY BURT RESTORE, other than what's done automatically.

Silenced these alarms at 7:35 AM -- H2CDS_IOP_ETMY_WATCHDOG, H2SUSITMBS, H1:PSL-MIS_FLOW_OK

Cheryl, Rodica

Today we concluded our thermal lens measurements of the H1 Faraday isolator for optical powers up to 140 W. In an attempt to correct for distortions in the beam shape observed with the beam scan, we repeated the measurements for several alignments and DKDP orientations. No significant diffence was found. Similar beam distortion could also be seen before the Faraday isolator, indicating vertical clipping after the EOM (possibly caused by a slightly eliptical beam coming out of the PMC?). More investigation needs to be done on the IO beam path to clarify this. For the thermal lens analysis only the data from the least distorted axis was used.

We also measured the thermal lensing of the Faraday with the eLIGO 3 mm thick DKDP piece, which has the same thickness as the aLIGO crystal, and it is considered as spare for Advanced LIGO.

The measured focal length of the FI with the aLIGO DKDP is +26 m, and with the eLIGO DKDP is +32m, the Faraday isolator being slightly undercompensated in both cases. This translates into a mode matching of 95% with the aLIGO DKDP, and 97% with the eLIGO one. Both values meet the IO requirements. M2 data and fit results are attached.

We changed the setup for isolation measurements and will do this tomorrow.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot. The data was taken from approximately 6 AM to 7 PM.

We've installed a minimum set of optics that are absolutely necessary for HIFO in HAM1. The list of installed optics will be alog-ed by Lisa.

We haven't payed any attention whatsoever to align them, as we don't have any beam for now. Things are just put in place, and we'll need to go back when the beam will be available.

Nothing could have been as smooth and as quick as this. One professor did all in-vac placement and bolt tightening. Don't know if these two things are correlated.

If we have time, we might install other stuff that are not necessary for HIFO in HAM1.

We finally got those Actuators attached.  A primary problem was the greater than expected compression of the Viton Cork Spring.  This required an unusual lift of the HEPIs to bring the Optical Table to elevation.  This ran the Horizontal Angle Mount to the limit of its slots and made attachment painful. In two cases we had to remove some material to allow bolt up.
After the Actuators we had the Cleaning Crew give things a good wipe down--thanks Cris & Karen!

Jason was at the ready then and measured position as reported below.

We followed that with an level/elevation check: -200.4mm Gz(0.4mm low) and level +-0.1mm

Keita Lisa & Matt then went in to add ISC things.

After they are done, before we do anything else, we'll need to check the level/elevation and adjust the payload accordingly.

JimW, HugoP,

We started adjusting lockers on HAM3-ISI today. The iterative process starts with unlocking the ISI and adjusting the balancing. When we did so, Jim and I noticed the optics of MC2 and PR2 were swinging. We stopped while still having two of the four lockers (C and D) locked.

JeffB went in with AndresR and locked M2 and PR2. 

Jim and I went back in the afternoon. We adjusted the vertical position of the lockers. We ended up swapping the shims of locker D: initially 122, now 129.

We adjusted the zero of the vertical CPSs on the new locked position.

We plan on adjusting the lockers horizontally, and the horizontal CPSs tomorrow.

   MC3 - Filiberto checked the system cables from the BOSEMs back through the chassis, etc. and found no problems. I have swapped in a new D1000234-96 connected to T3 - SD and re-centered the BOSEMs. MC3 should be ready to test. 

   MC1 - I swapped the M2 and M3 cables at the mock feed through and M3 UL still shows -4000 plus counts with no OSEM is connected, (should show 100 counts or less). Filiberto is going to look at his end of the cabling, amps, etc tomorrow.

Observed that the dew point of the X-end purge air has risen to -15C (should be <-25C) -> Found that the left drying tower isn't depressurizing completely during its regeneration cycle -> suspect components not in stock -> will repair when replacement parts arrive

After lunch, the forklift was craned across the beam tube in preparation for the doors going back on.

Early this week, the work platform was moved from BSC8 to BSC1 and a regular BSC cleanroom was moved into place over the work platform. Today, the cleanroom was modified to better accommodate the existing equipment. The E-module and spiral staircase were craned into the "beer garden". (NOTE: The E-module covers the lower portion of the regular stairway: please be careful of your head. The area of concern has been covered in foam and caution tape.) The bridge from the E-module to the work platform was installed (no modification needed). An aLIGO garbing/staging cleanroom was moved from BSC8 to the top of the E-module. The green iLIGO cleanroom was disassembled so that it can be used along the in-put arm for HAM2 work since we are stealing an aLIGO garbing/staging cleanroom for the floor level at BSC1.

• X-axis Position: 0.0 mm
• Y-axis Position: 3.1 mm West
• Rotation: 246 µrad CW