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.

Dave and Kiwamu

Kiwamu installed a new gigabit ethernet camera (cam03) today but its image was not opening on the workstations. I tracked this down to a typo in the overview MEDM adl file and the image is now viewable.

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.

17:07 I restarted the DAQ to resync it with the new h1isietmx INI file. Unfortunately some other front ends were MX glitched by this and required a /etc/start_streamers.sh MX resync. The front ends which needed this were: h1sush56, h1susauxh56, h1susey, h1pemmx, h1susauxex.

The frame data gap due to the DAQ restart is

Jan 15 17:07 H-H1_R-1073869632-32.gwf

Jan 15 17:10 H-H1_R-1073869792-32.gwf

We noticed when the HEPI was untilted, some of the ISI target locations were more different than we'd like.  Mainly the Stage1 X (~70um) & RY (5urads) and Stage2 X (5um) & RY (<2urads.)  The others were less than this.  With Keita's OK we reset the ISI targets.  This will translate the tilt of HEPI more completely to the ISI (TMS) and keep the ISI stages parallel.  This may be the better place to operate the ISI rather than having the stages tilted to each other.

The attached snap shows the ISI locations with the untilted HEPI before we updated the Targets.

We have gotten back the ISI performance, at least to a tolerable state for the moment.  Hugo doggedly compared all the filters between the ITMx & the ETMx to get the ETM in the same state.  It ends up being exactly as we had it last Wednesday when Fabrice worked with us.  Stefan has also 'greened'  up the 'State' so that may be helpful.

The state is:  Both ISIs use lvl1 control.  Both ISI Stage1s use 100mHz blends on X Y & RZ (horizontal dofs) and 750mHz on Z RX & RY (verticals.)  Additionally the ITMx has .45Hz notches engaged on X & Y.  For Stage2, the blend is 750mHz for both ISIs.  Both ISIs have been brought to this state with one click "! isolate iTMX lvl1" from the command medm.  It is possible that depending on how long the HEPI at the ETMX has been tilted, the T240 may be too rung up and they may trip the ISI as it attempts to isolate.  We aren't using the T240s in these blends and I'm pretty sure they won't be bothered so the WD trip level can be taken higher temporarily to stop the isolation interruption.

Attached is a plot of the ETM & ITM spectra.  The green ETM spectrum shows the more aggressive things we were attempting and the red trace for the ETM and the dashed trace for the ITM shows the state we are now in and last Wednesday.  We don't isolate as well below .1Hz but between .1 and .4 it is better and that seems most important.

Kiwamu with remote help from Rodica

I completed two missions as a part of the high power prep:

• I have installed the motorized rotational stage in the main path on the PSL table.
• I increased the laser power of the ALS doubling path by a factor of 10 while maintaining 1W incident on IMC.

Some pictures are available in ResourceSpace: https://ligoimages.mit.edu/?c=1434

Installation of the rotational stage:

The stage had been ready and sitting on the table for a long time (see alog 8731). First of all, I took the fixed-manual stage out of the main path. Then I removed the wave plate out of it and put it in the motorized stage together with a pair of the white rings which were also the stuff I took out from the manual stage. The motorized stage was then moved to the same place as the old wave plate had been. The position was fine-adjusted such that the beam goes through the center of the wave plate.

Power increment:

I rotated the wave plate which resides between PMC and the EOM to increase the laser power to 10 W. The idea is to give some more power into the ALS doubling path (see alog 9287) while mantaining the incident power of IMC to be 1 W. This means the new rotational stage is the one which decreases the laser power from 10 to 1 W.

In order to set the angle of the rotational stage right, I measured the laser power which would be incident on IMC as a function of the rotational angle. The result is shown below and also the raw data is attached.

According to this measurement, I set the request angle to be 56.1 deg in the medm screen. Plus, to always keep this angle until we are fully ready for 10 W, I physically locked the interlock switch of the rotational stage, so that the power can not change by accident.

Common parts:
=============
ALS_END.mdl
Added REFL_SLOW and REFL_B_LF routing for arm dither alignment.
SVN revision 6865

H1 only models:
===============
h1iscex.mdl
h1iscey.mdl
Added REFL_SLOW and REFL_B_LF routing for arm dither alignment. This routes the signal through the dewhitening whitening filters.
SVN revision 6866

h1asc.mdl:
Added ADC card 3, channel 17-20 (16-19) to h1asc model.  The last two (channel 19,20) go to green arm transmitted power, X and Y
SVN revision 6863 

Towsen Electric on site for lightning protection inspection
Snow King working on LSB water system
Tumbleweed bailing on X-Arm and at OSB

08:00 Sheila - LVEA working at HAM1/HAM2 area
09:00 Betsy - LVEA hunting for parts
09:27 Kiwamu -Installing rotational stage in H1-PSL enclosure
09:30 John, Richard, & Towsen Electric - LVEA roof lightning protection inspection 
10:20 Richard - H1-PSL enclosure on rotational stage
12:30 Vern & Patrick - CER and at HAM1; power recycle EtherCAT chassis #1 in H1-PSL
13:02 Dave – Working in CER 
13:17 Kiwamu – Installing rotational stage in H1-PSL enclosure
13:40 Filiberto & Frank – Pulling cable at End-X
13:44 Andres – Installing new EQ stops on H1-SR2
15:00 Safety meeting

Sheila reported an issue with the PMC transmission monitor which had shown a bogus low power readout (see alog 9120).  Since I happened to be in the PSL room this morning, I unplugged and plugged the lemo cable of the PD to see what was going on. For some reason, it fixed after I plugged it back. It now reads the correct power of about 11 W. Also, I could not reproduce the low power state by wiggling or unplugging/plugging the lemo cable. This is exactly the same situation as before (see alog 8622).

13:44 Andres installing new EQ stops on H1-SR2 M3 stage
14:20 Work completed

13:40 Filiberto & Frank pulling cables at End-X

12:30 Vern and Patrick in CER and around the HAM1 chamber. Power recycle of the chassis #1 E-Cat
13:07 Work completed  

09:27 Kiwamu in H1-PSL enclosure installing rotational stage (WP #4395)
11:49 Out for lunch
13:17 Kiwamu continuing rotational stage work in H1-PSL enclosure
14:30 Finished in H1-PSL enclosure  

After spending all day measuring the library of fiber modes on the ETMy monolithic, the saved data from the spectrum analyzer was corrupted.  Giles hunted down the cryptic hint which was apparently needed in order to not loose the data and we remeasured (and resaved) all of the data today.  He'll process the data and post a more detailed entry, but in a nutshell all 4 of the fiber violin modes fell within 1.5Hz of each other.  The tol is ~+/- 2.5 Hz.

Fiber Guards were added and it was left hanging as a single pendulum.

Meanwhile, we're working towards reattaching the rebuilt upper structure on the ISI/cartridge.

*  Interesting note - we've found 3 dead flies on the floor in the welding cleanroom (1 very near the monolithic yesterday morning, 1 a few feet away from the mono, and the other in the cartridge cleanroom adjascent).

Giles Hammond and I revisited the pulling machine alignments including the coaxial "red" and CO2 beam alignment. We tweaked the substrate mechanical alignment a bit as well as the CO2 beam pointing to the substrate. Alastair H. will travel in Feb. to pull fibers. We need to glue up some more substrates, enough to cover both ITMs.

Jeff B. and Andres R.

   The last set of transfer functions (aLOG #9235), although reduced, still show L to Y cross coupling. To address this we removed the LF, RT, and SD BOSEMs and adjusted their flags to improve the horizontal alignment. The BOSEMS were reinstalled, centered, and set to 50% light. The transfer functions taken last night show an improvement in the L to Y cross coupling. The plots are attached below.

   The scripts and results files have been committed to the SVN repository. 

13:20 restart of epics alarms email service after a configuration change.

Kiwamu, Patrick, Richard, Vern

We power-cycled this chassis in an attempt to clear a warning preventing Kiwamu from operating the H1 PSL rotation stage. This seems to have fixed the issue for now.