Final inspection was completed by 10:00 am and doors were back in place by 11:00 am. Tooling was prepared for transfer to Xend. FTIR kit will be sent off on Monday.
Image files have thumbnails, but PDFs do not. For multipage PDFs, the thumbnail could be just the first page.
This PDF shows that the RMS of the PD signals is dominated by 60 Hz + harmonics as we suspected. Unfortunately, it looks like we would have to notch out many, many harmonics to appreciably reduce the RMS. Perhaps we should use a low pass in combo with some comb filters?
In order to reduce the noise in the channel, I added a Comb filter into the CS_CHAN_NN filter banks to knock down the first 8 harmonics. Also added a 2nd order Butterworth low pass at 11 Hz to get rid of the HF harmonics. The RMS was reduced by 100x.
Restarted the rotating lissajous search pattern on the ALS table PZTs, but still now blips seen in the baffle PD times series...
Dust alarm levels at EY for location 1 were set to:
0.3: minor 20000 major 100000
0.5: minor 10000 major 50000
[Aidan, Thomas, Elli] Following some strange behavior in the Hartmann sensor signals, we checked the layout of the telescope on the ALS table and found that the lenses were out of position. The target and measured distances are show in the following table.
| Distance | Target | Measured |
| F0 to F1 | 614 mm | 675. mm |
| F1 to F2 | 1313 mm | 1232. mm |
| F2 to HWS | 1338 mm | 1530. mm |
We adjusted the positions of the lenses until they matched the target distances.
Separately, I calculated the tolerance of the conjugate plane of the ETM near the HWS to the position of these lenses. The ratio of the displacement of the conjugate plane to variation in the distances between optics is ~14x for F0-to-F1 and ~ 0.02x for F1-to-F2. As such, we placed lens F1 on a translation stage oriented along the optical axis. This will give us fine control over the position of the image plane of the ETM near the HWS.
The beam now looks much more uniform and Gaussian on the HWS. The beam size is 11% smaller than the expected beam size of 1.58mm (see attached plot).
We removed the Hartmann plate from the sensor last night and left a version of the code running that measured the beam position on the CCD. Watching this in real-time we could see the beam wandering around as Keita and Rana swung the TMS telescope around.
- 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.
Excellent Summary for your final Operator log. :) We'll miss 'em!
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:
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.
As a side note, 1/20 angle reduction only applies to the tilt upstream of TMS telescope (e.g. PZT on the ALS table).
For the rotatoin of TMS itself, it should be 19/20 or 21/20. However, we (Rana and I) felt as if TMS rotation is not producing enough beam rotation. We should calibrate the TMS angle to know how much we're actually tilting it by measuring the displacement of the retro reflected beam on the ALS table.
Also, we need to keep the optical axis fixed to the TMS even during the alignment, which (among other things) means that the TMS angle and the ALS beam angle on the ALS table should always be moved by the same amount. Elli and Thomas are working on the QPD servo for this.
Some details on the sensitivity of the search:
* For the ETMY camera, we are only a few meters from the TM. The iris is opened up as far as it can go and still stay nearly focused on the mirror (as seen w/ illuminator on).
* For the ITMY camera, we are ~30m away at the spool position. A large maglight flashlight injected from there can easily be seen on the baffle, the chamber, and the optic.
* The light from the flashlight shows up as ~10000 cts on the baffling photodiodes (mounted near the ITM). Wiggling the green beam from the end produces no signal as seen on the camera and if it produces any signal on the baffle PDs, it must be below the noise level of ~50 cts-rms. Given that the flashlight puts out ~500-1000 lumens, how big of a signal should the green beam make if its the right size?
* Assuming that we inject ~10 mW into the ETMY and that it has a transmission of ~1.5% for 532 nm, we should get ~100 uW of light at ITMY. By comparison, when we hunted for the iLIGO beams, we were injecting ~100 mW at the PRM and ~50-100 uW would get through to the ETM before lock (in the single arm config). The silicon CCDs should pick up the green light much better than the IR, so we should be seeing some beam on the chamber walls, etc. We were injecting non-integer frequency sine waves simultaneously into both pitch and yaw for the PZT, so I think its unlikely that we were unluckily sitting in some dark space.
* We need an SEI & SUS expert to inspect the HEPI/ISI & the ETMY angle biases to ensure that they are pointed in the right direction as determined by the IAS.
Video of the swinging beam on the ITM (left) and ETM (right)
Images of the ETMY as seen from the spool cam: illuminator on (left) and off (right)
I calculated roughly what the intensity of light should be on the baffle PDs. Rana's 500 lumen flashlight was emitting around 10W of light. I assumed this was filling an area roughly 1m in diameter - this yields an intensity of 13W/m^2. The corresponding intensity for the green beam at the ITM (assuming 100uW is transmitted through the ETM and the beam radius is ~5cm at the ITM) is about 12mW/m^2. So the response of the PDs to the green beam should be ~1000x less than the response to the flashlight.
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.
(GMoreno, DSellers, BBland, GMorenoJr.)
ITM08 ears were bonded succesfully, ears with SN 59 and SN 64 were used.
SN 59 was used for side S3, and SN 64 for side S4.
After setting the mass on the base of cake tin, a full inspection of ears and mass was performed, no problems found.
Attached are photos of ears on ITM08. Also a photo of the mass as I was putting it away in its cake tin, ready for shipping.
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...
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.
Signage was added this morning: DO NOT ENTER Sensitive measurements in progress. If access is needed, please contact Control Room at ext. 202. See photo below.
