We mounted the second green Faraday on a 4-axes mount and reworked the Green injection path to make the beam shape less clipped. We needed to go close to the edge of the EOM and Faraday aperture to get the best beam quality.

As for the EOM, the best beam shape was achieved when the beam is very close to the top edge of the output aperture, maybe it was already touching the hole. We backed off the height adjustment screw (closer to the output) of the EOM mount by half turns so there's no apparent clipping but it's still very close. With this backed off position the beam shape was not as good but we called it good anyway as we couldn't do anything about it.

Anyway, since the center of the aperture for Faraday as well as EOM is NOT the best position as far as the beam quality is concerned, Faraday and EOM should be on adjustable mount. The first Faraday is still fixed, and this means that the beam is not horizontal along the beam path through the first Faraday, which is OK but not ideal (e.g. the beam is not completely centered on the first lens).

We still don't know if this new beam path arrangement is any better  or worse than before.

We took some beam profile measurements, which Sheila will post later. Quality of the injected beam is better, the beam coming back to WFSA looked better than before, WFSB was worse.

PUM P injection to OL Y transfer function, green is old and brown is now. Also shown in blue is the Y to Y transfer function so that you can tell if the coupling is large or small.

The peaks were reduced by 10 to 12dB and I guess this is good enough.

Craig Conley, Doug Cook, Travis Sadecki, Rick Savage

Today we used a 1047 nm alignment laser to assess the as-installed alignment of the Pcal periscope optics for the Pcal paths.

We didn't yet verify the alignment of the ETM camera  view optics because the viewports for those paths have not yet been installed.  This will hopefully be completed next week.

The alignment looks very good.  One mirror on the upper beam path required a slight adjustment, but otherwise everything was well-aligned as found.

Note that the first contact has been removed from both sides of both Pcal windows on the A1 adapter (thank you Margot).

We transitioned back to Laser Safe.

We removed the YLF alignment laser and we are closing the work permit.

The four pairs of special 1 micron-only laser glasses are being returned to the LSB Optics Lab.

The work permit for this task has been closed (signed off).

Thanks to JustinB for all the assistance with the temporary SOP.

Please log excursions to Y end.  If you look on OPWS0 you can see if it is still running.  It will likely be done fairly early SaturdayAM so you'll mostly be in the clear.  Call me-619-3304.

J. Kissel, A. Pele

We had a huge wind storm (30 mph average, 50+ mph gusts) this afternoon that was taking down HEPIs and ISI left and right. Moving the blend UP didn't help. We decided to just leaving the ISIs off for a bit just to gather environmental data and watch the storm roll by, since no interferometry could be done. 

For 1 hour, starting at GPS 1078868350, Mar 14 2014 21:38:54 UTC,
For ITMX and ITMY
HEPI - isolation level 1, 'pos' blends
ISIs - Damping Only
QUADs - Damped

After an hour or so, HEPI ITMX tripped.

As of Mar 15 2014 00:40:00 UTC, all 4 BSC chambers have been left at their believed to be best performance during low-wind times:
HEPI - isolation level 1, 'pos' blends
ISIs - isolation level 3, 'TCrappy' Blends
QUADs - Damped

Got the CPS racks grounded and wired up.  Fine tuned the Dial Indicators.  Still need to do some cable strain relief but I'm out of hardware and this is not the only place that is needed.

Ready for chamber cleaning to prep for opening.

I ran a few static tests yesterday on ETMY HEPI.  Things like linearity & range of motion etc.  Attached is a two plot of trends on the HEPI Cartesian basis IPS.  X & Y have moved a few ums while Z and Rx & Ry are pretty steady.  Rz has rotated a little more now out to 22urads.  Again this is good for the alignment now as long as it doesn't go further.

Dave, Stefan

We tried a PRX length measurement, but had to conclude that
- REFL is swamped with the direct reflection signal - the expected broad bump is not visible.
- POP has too much attenuation - he do not see a beat note at all.

The interferometer is thus available for the rest of the night.

All actuator sub assemblies have been completed. Time with Jim is required to add these sub assemblies to the ISI. All of the flexure sub assemblies 0-1, and 1-2 have been completed. The granite table has been cleared in preparation for monolithic plates, which were brought over to the staging building this afternoon by Apollo. 

Clean-up of RGA is slow at the reduced temperatures used -> RGA is isolated from the BT via (2) series-connected closed 1 1/2" valves

6:20 -> Working at End X – Jodi
7:20-8:10 -> Heading to End Y – Jodi
8:45-9:10 Going to End Y to work on dust monitor – Jeff.B
9:01-11:54 HEPI work on HAM5 - Hugh
9:15-9:30 Dust monitor work by HAM5 (LVEA) – Jeff.B
9:24-     Going to End Y – Travis
9:30-10:00 End Y cleaning - Karen
9:35 -> PSL Check List (OK)
10:16-13:39 H2 Laser enclosure work – Gerardo
10:38-11:04 Working on SR3 (LVEA) – Jeff B.
10:43-11:30 Searching for cables at Mid Y – Filiberto
10:45-12:35 Going to End X (cleaning) - Cris  
11:20 -> Laser turned ON at End Y – Rick S.
11:30 -> LVEA transitioned to Laser Hazard - Justin    
13:20-14:30 Back to HAM 5 – Hugh
13:30-  Working at End X – Keita
13:58-  Joining Keita at End X – Sheila
14:08-  In LVEA working on nitrogen piping - Apollo 

Travis, Margot, and Kate

Removed the horizontal 4" wafer from the beamtube (between the purge air port and ACB). The 1" optic that was placed with the wafer couldn't be removed (no PETG containers available), so it was moved to the opposite tube for the time being. When possible, it should be moved back to its original location or removed. A new 1" optic (s/n 1195) was mounted vertically to the QUAD.

Refer to Betsy's earlier alogs on contamination in BSC10 (10522, 10675 & 10686). There is still a lot of particulate contamination, even after cleaning. The first photo shows a wipe used to clean the tube on Monday. Dust, metal, a few red fibers, and white fuzzies were observed on the tube floor from the ACB all the way to the PCAL periscope. The iphone photos and videos don't really do it justice. There was a much higher concentration of white fuzzies along one half of the tube (on the right side, if you have your back to the ACB and are facing the periscope). Travis took an FBI sample, and then vacuumed the area.

We've had at least 6 times this morning that HEPIs have tripped on the L4Cs, and there isn't a clear reason looking at the seismic conditions why today should be worse than other days.  The chambers that have tripped are (at least ) IMTX twice, ITMY once, HAM2 once, BS twice.  Attached are plots of the two most recent BS trips. 

No one on site really has the time to sort through the data and figure out what is happening, is there anyone from SEI or DetChar that can take a look?

Thank you,

Sheila

Dust monitor #2 at End-Y (next to the BSC10 chamber) and dust monitor #1 in the HMA5 cleanroom are both online and functional. 

It didn't seem like there was much seismic noise based on the PEM FOMs, but they both triped around the same time.  Plots for ITMX attached

Offending Y2P peak between 1 and 2Hz (pink) was removed after a new decoupling filter was put in place (green).

In the H1:SUS-ETMX_L2_DRIVEALIGN_Y2P filter, I put the same invP2P filter in FM1 as in the P2P path, then added a diagonalization filter ("Y2Pdiag") in FM2, and another filter that is a 3rd order elliptic BP in FM3. I didn't try to remove 0.4-0.5Hz Y2P peak, it's not great but probably good enough.