Managed to get three of the Horizontal Actuators attached today.  Hopefully will be allowed to continue tomorrow.  Just the NE Horizontal Actuator remains to be connected.  Then we'll release all the actuators; they are locked in a mid-position during installation.  Hopefully (Yes I do lot of hoping), the system won't move too far from aligned position.

Most pressing:
ETMY screens modified in a way that left them with white boxes - broken!  Dave is currently working on fixing it.

Activities:
Vincent - running a measurement on BSC8 - done at 13:50
kyle - moved a cart from ham3 to ham6
Dave - restart H2 DAC, restarted H1 DAC
Forklift - work going on early afternoon at C&B
Douglas - retrieved items from HAM4 clean room
Keita and Bram to end station - worked on the table, and found that ETMY screen has white boxes
Tour in the LVEA: 2:40-3:30
Betsy - work on MC2 chamber side
Hugh - work on SEI

Today, the guys finished fully suspending the glass MC2 and took a preliminary look at it's height and pitch alignment.  With the optical autolevel and a height guage (standard HXTS alignment procedure), the height measured to be at nominal (214mm to better than +/- 1mm). 

The roll of the optic is out by 0.8mm over the distance from the left prism to the right. 

The pitch was measured via looking at the pitch of the side scribe line on the optic (which is known to be crooked by ~0.1mm over it's length) so is estimated at ~4.5mRad.  Independently, an optical lever was set up near the top edge of the optic (above the FC, so yes, high on the 27m ROC surface) and the pitch again measured to be 4.5mRad +/- 1mRad.

We're not sure what the IAS requirements are, so we'll need to find those before determining what errors to improve.

I installed an accelerometer to the table surface by epoxying the sensor to a metal cube, epoxying a layer of cling wrap to the bottom of the cube, then epoxying the whole thing to the table. The HEPA fan was turned on while the epoxy was curing, then turned off afterwards. A picture of the setup is included.

[covering morning part of shift for Cheryl]

This morning's primary activity is Reflective Memory work by Richard & Dave. (taking down the ITMy and also ETMy, as well as the DAQ), so this left the morning open for "loud" activities since there were no SEI or SUS measurements planned.  This work should be complete before 2pm.

Other Activities:

• Starting 1pm:  SUS Crew would like to start work outside of HAM3 (hang MC2)
• Most of day, starting at 10am:  SEI Crew continued Actuator work on HAM3.  There could be cabling work on HAM3 later.
• ~7am:  porta potty service on site
• ~845am:  Jonathan Hanks ran out to EY (non-laser area) for wireless work (ok-ed by Keita)
• 9:30am:  Unifirst on site
• 8:20-10am:  Praxair onsite to fill EX & MY (CP3) this morning
• 10-11:30:  Apollo taking forklift to MY and moing stuff inside
• 10:22:  Received a call from snobby telemarketer ((541)654-0612)

I'll leave the cavity locked and the ISCTEY HEPA fan off.  A thunderstorm brought strong wind between 5:20 and 5:30UTC (22:20 - 22:30 local), which made the lock rough.  It is currently raining hard with occassional thunder, but the lock has cleaned up and the spectrum looks decent.

The DC output of the PDH detector on ISCTEY seems low, so I went to measure the power on the PD.  The power meter says 2mW.  The detector gives 17mV at the output, and it seems that the PD has 10 Ohm transimpedance with a gain of 5 and a responsivity of 0.3A/W at 532nm.  17mV / (5 * 10 mV/mA * 0.3 mA/mW) = 1.1mW, which is in the ballpark.  The coupling efficiency is probably not good enough to achive 0.3A/W, so that might explain some of the discrepency... in any case, the real mystery is why we have only 2mW on the PD.

The SR785 reports coherence > 0.999 above 1Hz between the demod board Imon (output monitor) and the VCO monitor.  That signal passes through the CM board and the VCO filters, so they are not adding any visible noise.

There is good coherence between the ISI stage 2 signals and the cavity length.  I used the nominal calibration for the GS13s to nm (3 poles at zero, 2 zeros at 1Hz Q ~ 0.7, 1 nm / (2 pi f) above 1Hz), and it appears to match the VCO calibration for the cavity length quite well below the SUS resonances.

I also include a couple of driven measurements.  The current motion of the optics is at the limit of our ability to keep the lock (due to alignment flucutuations and dominated by ITMY), so it is hard to drive hard enough to get a good measurement without breaking the lock, but I was able to get some coherence.  I wonder if the drop-off below 200mHz in the driven measuements is due to some tilt-horizontal coupling in the drive, or possibly due to pickup in the GS13s.  The suspension resonances seem to amplify the motion by a reasonable amount, given that we can't expect to achieve very low Qs with the damping all at the top stage.

Attached are plots of dust counts > .5 microns in particles per cubic foot.

I measured the power going into the AOM to be 32.6mW but only got 5.8mW into the EOM. After adjusting M24 to improve the pointing into the AOM we now get 18.4mW at the EOM. However, the rest of the FSS path is now misaligned and will have to be worked on. The ref cav still flashes so it's fortunately not too far off.

HughR, GregG, JimW,

Today, finally, all vertical HEPI actuators were attached at HAM3. We will need verification from IAS, but at this point the position does not seem too terribly disturbed. Only a few thousands here and there based on what our dial indicators tell us. Most of the piers have very little room between the "back" side of the actuator and the pier (< 1mm), which will make things very, very messy if we need to re-locate the ground side of the actuators in the future (i.e. off-load the springs, shift the housings and then redo the alignment). Tomorrow, or whenever is convenient for One Arm people, we'll attempt to attach the horizontal actuators.

Andres R, Betsy B, and Jeff B took the transfer function for Phase 1b testing of the HSTS MC1 suspension. This data has been plotted and is ready for review.

With septum-separated VE volumes vented, the ion pump controller achieves mid-scale current (with HAM3 East and West doors removed and with their annulus ports plugged with rubber stoppers).  

M. Evan, J. Betzwieser, (J. Kissel)

See LLO aLOG 3850, for details, but this may be why we've been having so much trouble with driving from the L2 Stage.

This bug fix has not been implement yet on the LHO system, as we're waiting for the incoming updates from J. Kissel.

The ETM optical lever shows interference fringes when the TM is subject to a large longitudinal drive.  I guess this will go away when the front surface beam is found, but it is something to look for on all the optical levers to be sure that we don't add noise from longitudinal motion.

Due to an apparent increase in noise when the cavity was well aligned, we (Bram and Matt) suspected that some of the 532nm light retro-reflected from the cavity was getting into the laser and causing problems.  To test this, we added a second faraday after the laser on the ALS table (ISCTEY) and realigned the beam.  This appears to have had the desired effect (see plots), but in the process we discovered that some work will be needed to understand the REFL RF photodector, as it seems to be overfilled and its alignment may change our noise floor.

We also found clear fringes in the cavity error signal (PDH_IMON) even with the ITM misaligned.  The fringe velocity is senstive to motion of the ASL table, and to the state of the HEPA fan on the table.  These fringes are only a few mV, but they may be a noise source and will need to be investigated further.

The cavity is locked and operating normally as of 3:00 UTC (20:00 local).  The ISCTEY HEPA fan is off.

The addition of a Faraday in the green laser path has reduced the operating power by about 20%, so REFL_PWR_MON_OUT between 5000 and 8000 indicates that the cavity is locked and reasonably aligned.

More detail will follow, but we determined how to get the length to pitch decoupling filter (jsut a confirmation), and using the Quad models we generated the length-to-pitch decoupling filter, for placement in the 'DriveAlign Matrix' in the M0 path.

The frequency dependent response is -Length-to-Pitch / Pitch-to-Pitch (with a gain factor).

Using plotallquad_dtttfs.m and quad_l2p.m in /ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools, I generated Dl2p_2012_07_13.mat. Is has a frequency vector and the coupling vector.