- One Arm Test Begins: Gate valves opened, and the laser has been sent down the arm. If you find the beam, let Keita or Rana know ASAP.
- Safety discussion: If the work involves manipulating components in the beam path, including viewport covers and gate valves, the LSO must be notified. In addition, all viewport covers must bare a warning that removal requires approval by the LSO.
- BSC8: Transfer functions today. Discussions at morning meeting about coordinating cleaning with measurements. Decision was to hold off on cleaning until this is resolved. Also, GV-6 was opened. In addition to Illuminator lights, Rana and Keita were using a flashlight to locate the green laser beam.
- BSC6: HEPI transfer functions. Richard installed cameras yesterday and set up the Illuminator lights. The cameras are still being worked on, as the analog feed from EndY is not great.GV-17 was opened.
- HAM5: ICC ongoing.
- HAM2: ISI - Electronics work.
- HAM3: ISI - Richard doing cable-pulling prior to entry
- ISCT4 is cleaned and ready to be moved to Betsy's spot.
- H1 PSL: Michael worked on the software and network connections.
- MidX everything out, grout beginning next week.
- EndX prep beginning.
- Craning: Moving doors in the LVEA (HAM5 and HAM6), crane in staging building (Corey).
- LSB HVAC work to begin Friday morning.
- Pickup+Delivery of cardboard recycling.
- Riverside High School visited in the morning.

We set up a CCD camera looking at ITMY and the entire baffle and some more, sent a green beam from EY, modulated its angle by using PZTs, and found nothing on the camera. No luck with the baffle diode, either.

It seems like the beam is not getting to the corner station at all.

One (or more) of three things should be true:

1. The ETMY is not pointing to the ITMY. The beam from ALS table is very close to retro-reflection by the ETM when TMS and MCL PZTs are in a neutral position.
2. Because of a factor of 20 reduction in angle in the telescope, we're not wiggling the angle enough (however I doubt this).
3. Mode matching is so bad that, by the time the beam reaches the corner, the beam diameter is 4m or something.

Tomorrow we should use HEPI and/or ISI to move everything by a milli radian or so in YAW.

The reason why I think we're already wiggling enough is because, when we wiggle MCL PZTs, I can see on the CCD camera monitoring ETMY that the motion is so big the beam falls off of the primary.  It's not impossible that this is all in translation and not in angle, but we used both PZTs that are placed at different Gouy phase positions and we didn't see anything at IY.

Attached are plots of dust counts > .5 microns. I have also attached plots of the modes for dust monitor 1 at end Y, dust monitor 1 in the LVEA and dust monitor 1 in the optics lab to show when they were disconnected. The disconnection at end Y appears to have occurred before the LVEA and labs, indicating that something happened there before the accidental power down of h0epics2.

On behalf of Gerardo and Danny:

Both ears were silicate bonded to the LLO ITM (ITM-08) this week.  The mass has been stowed back in it's cake tin and await shipment out to LLO. 

h0epics2 was accidentally powered down. This affected the following IOCs: h0dustlvea, h0dustlab, h0dustey, h0fmcs, h0weatherex, h0weatherey, h0weathermx, h0weathermy. h0epics1 has been powered down and its power cables moved to h0epics2. The only IOC running on h0epics1 was h0time. This has not been restarted. There seems to be a problem with the mouse on the KVM for h0epics2. A usb mouse can be used until this is fixed.

Earlier in the day we had a hard time locking refcav, and I've found that the voltage supply for the RF amplifier was current limited.
 I set it to maximum and the problem was gone.

Rick S, Michael R

After some work to optimize gain settings the FSS_FAST_GAIN has been set to 0.2 and FSS_COMMON_GAIN to 0.8. The gain slider on the MEDM screens is not accurate - a change of 0.1 dB on the slider is actually a change of 3 dB.

A new DBB measurement was created and is attached. A snapshot of the open loop transfer function and the error signal are attached as well.

Installed one watec 902H with a 300x zoom lens on the Y beam manifold looking at the baffle for ITMy.  Installed an illuminator on a BSC8 port in the vertex with remote controllable power supply for access from EY.

Installed a Sony camera on BSC 6 spool looking at the ETM.  And an illuminator on a spool port that is powered from the old DC power rack in the LVEA.  

Ported the video signal from the LVEA to the End station and From the end station to the MSR but have a problem with the MSR as we can not get sync. so lines are rolling through the frames.

Will work on getting video into the control room later.

GregG, MitchR, CoreyG, JimW

Today Stage1 was completed and flown to the test stand where it was connected to Stage0 on our seventh assembly. This means that MOST of the mechanical superstructure on LHO's last HAM ISI is completed. Still a lot to do (spring pull-down, actuator and sensor installs, optical table, etc.) but most of the remaining sub-assemblies are put together and are just waiting to be attached. The finish line has never been closer...

(Betsy, Danny)

The first secondary prism was glued to MC2 yesterday. It witnessed a 12-16 hour room temperature cure followed by 6 hours of heat lamp curing.  The optic was stowed in its cake tin for HVAC work planned in the lab tomorrow.  The second primary and secondary prisms will be glued on to the optic next week.

I applied lots of caution tape to the bottom of the spiral staircase to prevent folks from accessing the stairs, E-module, or work platforms around the chamber. I will apply appropriate signage tomorrow.

I spent some time today clearing paraphernalia from ISCT10 and then consulted with Keita as to disposition of said items. Keita will follow-up on getting items put away appropriately. He also asked for the table to be craned into the Squeezer Enclosure so Bubba and crew will take care of that tomorrow.

First thing this morning, the doors were returned to HAM6 and the south door was removed from HAM5. Brushing was completed in HAM5 before lunch.(The condition of this chamber is much better than what we saw in HAM6 and cleaned up nicely.) After lunch, the crew did first vacuum, unwrapped the support tubes, vacuumed the bellows, and started wipe down. By the end of the day, about 1/2 the chamber had been wiped down: that is much closer to the rate of progress that we are used to instead of the VERY SLOW pace we saw in HAM6. We hope to close out tomorrow.

 

Kyle- 
Soft-closed GV6, roughed-out GV1 annulus, valved-out BSC8 annulus aux. pump cart, opened GV5, GV6 and GV17

One of the GS13s of HAM-ISI unit #6 (Pod #94) appeared to be defective this week (see aLog 3183).

Greg and I opened it this morning. Two flexures were broken.

• D0901318-v3, s/n 124 (Pic. 1)
• D0901319-v4, s/n 199 (Pic. 2)

One can see wear on the non-broken side of D0901319-v4, s/n199  (Pic. 3,4). The pattern is very similar to what Jim reported in the SEI Log a few months ago.

We also found a small flexure debris. This debris was identified as being part of D0901318-v3 s/n 124 (see black line on pic. 5).

The pod was tested at reception on a leveled surface. Nothing abnormal could be seen on its response at that time. It was then installed in the ISI. No major event was reported (drop/shock/…). Spectra were taken with the ISI tilted and the pod appeared defective. Any spectra, even with the ISI leveled showed it defective after that.

As it already happened, it is possible that the shocks, endured by the instrument during its shipment, damaged the flexures. In these conditions, tilting the pod back and forth to install it, and/or tilting the ISI for testing purposes, could have lead to the breakage.

We have shockwatch data for this shipment. Greg will post it later on.

[Thomas, Aidan]

Thomas and I tracked the source of clipping on the Hartmann sensor beam. The return beam from the ETM was hitting the edge of one of the mirrors in the back corner of the ALS table (see attached diagram). We tweaked the alignment so that the beam was centered on that optic.

The new beam profile on the HWS is attached. There is no sign of clipping now, but the beam quality is a poor Gaussian. There also appears to be horizontal fringes on the beam.

Max F., Keita K., Daniel S.

We had a hard time finding the beat node by adjusting the crystal temperature. Once we came close to the correct frequency the line would simply vanish. This seems to be related to mode hopping. The diode current was about 1.43A. We noticed that increasing the diode current by simultaneously adjusting the temperature to keep the beat frequency close to 40MHz allowed us to widen the acceptable temperature range and improved the beat node strength. Around 1.9A there was another mode hope, so we backed off the diode current to 1.666A. This re-adjustment of the diode current seemed to have increased the gain in the PLL. We had to reduce the common gain to -23dB (down by 3dB) to make it stable again.

We also found that the gain in the digital temperature stabilization servo only has a small range where it would work. Adding 10dB would make it unstable, whereas subtracting 10dB made it go to the rails. Even with the correct gain, we noticed that the PZT voltage would often go beyond +/-1V. Our readback has a gain of 10 and saturates just above 1V. (This readback is used as the error point of the temperature stabilization servo.) The following changes were made to the ASL common mode board, S/N S1102638 (H2 EY): 
R272 removed (from 374), 
R271 replaced by 0 Ohm (from 3.32K). 
The readback now has a gain of 1 and the temperature servo should work over the full PZT range.