Ground loops for HAM6 suspensions completed. Looked at OMC, ZM1, and VOPO. Found short on ZM1 pin 2 shorted to chamber ground.
Slawek, Sebastien, Travis
After the usual fussing (care) by a perfectionist team, the last AMDs were successfully glued to the flats of the ETMX test mass! Well done guys!
The tooling will be removed tomorrow mid-afternoon.
All 4 H1 test masses now have AMDs installed (4 each).
I'll state again that I'm impressed by how easy the tooling is for this in-situ install and how issue-free the process was.
Replaced worn out relief valve on air compressor #4 for the purge air skid at X-End station.
Replaced burned out indicator lights on the purge air skid at the X-End station.
(Corey, Daniel) 3:00 - 3:40pm
Installed (qty2) light piping for the two beam paths coming out of HAM6. The Viewport Cover/Guillotine was in place for both and the plastic Guillotine is also in place & will need to be removed when people want to work on beams for this table. This completes WP#7571.
We are declaring victory on CP4 bake at MY! Rai Weiss and Dennis Coyne gave it their blessing. :)
Attached is a spreadsheet with RGA scans showing partial pressures of residual gases. Total pressure = 2.4e-9 Torr for the post bake scan. LLO’s CP4 scan at their EX serves as a reference/baseline (coincidentally we’re both changing states of our #4 CPs). I also included a scan of our CP4 before the bake, but after the LN2 was boiled away and ice pumped away (total pressure 2e-7 Torr) in Faraday mode. Not very useful, but it’s data. We baked our newly installed RGA in situ with the CP bake so we never captured a baseline.
Comparing LLO’s reference to our post-bake, the peaks relative to each other look good, expect maybe for AMUs 50-60. Note that LLO’s scan is from an SRS unit and ours is from a Pfeiffer unit. I don’t have Torr/A conversions for these units specifically. Based on VBO scans, we know that the Pfeiffer ion current correlates closer to pressure than the SRS:
Pfeiffer = 1.3 Torr/A of Ar
SRS = 367 Torr/A of Ar
I used these values to convert to Torr and included that plot as well.
We have a new peak at AMU 7. Probably from baking the old 10” CETEC valve with o-ring gate seal.
After the annulus piping is installed and GV electrical connected, we will open GV 11 first to expose the bake volume to CP3 and IP9 and collect an RGA scan and finally open GV12.
CPS Z/RX/RY location residuals are all <15 micron/microradians indicating the table hasn't move much since they were last zero'd (around the time of the last closeout). Today's transfer functions (first image) look much like the Apr 26th measurements (second). I also replaced the 4" cc sample on the table earlier today. Think the chamber is good to close up.
I should mention, I left the ISI unlocked.
The periscopes and beams were realigned, now that SQZT6 is in its final position.All three beams travel down the periscopes and make it to the photodiodes for locking green. The CLF DC has been temporarily hooked up to a Thorlabs PD that is in the homodyne path. For reasons unknown the green transmitted beam seems even weaker than before.
Still to do:
Added 50ml water to crystal chiller and 100ml to diode chiller (for evaporation). Both chiller filters are clean and clear. No debris or discoloration visible in either filter.
Posted below are the ISI CPS Noise Spectra check plots. There is work going on in HAM6 and at End-X, so these plots are a bit off the norm.
Chris, Mark, Tyler, Gerardo
Removed HAM 6 north and south doors Wednesday morning and tacked south door back on in the afternoon. Today south door was torqued. North door still off.
HAM 6 north door installed today.
The LVEA has transitioned to LASER HAZARD . Work permit 7566 is complete. This is under work permit 7568.
Planned Activities:
Tvo, Alexei, Dan
We took some more beam profiles of the single bounce (off of ITMX) IFO beam in HAM6 as the north door is off. We took measurements from the edge of the HAM6 table near the viewport and up to OM1. At first glance it seems the astigmatism of the IFO beam is not as bad as our previous measurements. However we still need to analyze the results. We don't have the OPO beam available at the moment so we couldn't profile that, perhaps we can before the doors go back on.
As we were there we also tried to profile the beam shape change induced by the SR3 heater. We got the heater up to ~70C and took profiles with the nanoscan in a single position near the HAM5 viewport. Along with the OMC mode scan results we took the other day we are hoping this will allow us to narrow down where in the beam parameter space we are. Results to come.
Attached is the analysis of the beam profiles taken 50.5'' from OM1 as the SR3 heater temperature increased from 30 to 75 C at 5 W requested power on the SR3 heater.
The starting beam size was (2401.2, 2375.6) um and the final size was (2310.5, 2258.7) um.
The ellipticity (1-b/a) of the beam varied from 0.01 to 0.02.
Attached is the analysis of the last set of data taken during this measurement.
Here the nanoscan was positioned 21' away from OM2, and the SR3 heater was left for about 15 minutes at 75 C to come to equilibrium.
The power to the SR3 heater was then cut and the beam size was tracked as the temperature decayed.
The aim of this exercise was to observe the optical transient of the SR3 by trying to find the point where the beam size would start changing after the power to the SR3 heater was cut.
20 minutes after the power was cut the beam size had not changed significantly and we stopped taking measurements.
Aidan requested some pictures of the EY HWS setup on the table in preparation for next weeks upgrade, pictures attached
For reference, the layout is given in https://dcc.ligo.org/D1400241
For reference, the layout is given in https://dcc.ligo.org/D1400241
Apollo TJ Daniel
All squeezer beams are clearing the viewports.
The south door is tacked on and can be torqued down.
SQZT6 has been moved into its final position and its feet outlined on the floor.
A note on the process: to make sure that the beam was actually going to make it out, Jenne and I first placed the viewport emulator on top of the HAM6 N door that was laid down flat. Since the emulator was designed for iLIGO viewports, the extra covers and shrouds and other safety features make adjusting the emulator rings basically impossible. We didn't adjust anything because it looked to be good enough for what we could tell here. After Dan B, Jenne and I rearranged the flange protectors and then mounted the emulator, I pulled out the plumb line and the center emulator ring, the main one we were worried about, seemed to be in the correct spot. Daniel double checked with me and we agreed that it may be off slightly in the horizontal, but we could work with what we had.
Now for the aligning. I had a laminated piece of paper with a hole the diameter of the viewport cut out of it that we could place on the ring to make sure that it would actually go out (see attached). We also marked the wall with a dry erase marker to easily gauge how much we need to move the beam (see attached). We got them to a good point and then checked the the beam diverter beam was good as well, it was. With the door tacked on we did a final check it it all looked good (see attached).
The data retransmission rate between the data concentrator and the frame writer machines has been higher than we would like as we have upgrade the OS of the daqd systems to Debian 8. WP 7558 was opened to explore changes on the spare/test frame writer to see if we could lower the retransmit rate. After looking at timings yesterday one of the 'producer' threads, which verifies checksums of the data as it comes off the network, was found to be running long at times. Today I put in more efficient checksum code* into the frame writer. This gives us an immediate savings of 15ms and a more stable timing of the thread in question. In the attached image you can see a few important points. 1. The PRDCR_CRC_TIME_CRC_MAX_MS value is 15ms lower. 2. Thus the total time PRDCR_CRC_TIME_FULL_MAX_MS drops as well increasing our safety margin 3. This is a big improvement on the spike at the 4m mark which jumps above the allotted time for the thread (this spike is ~70ms!). * This was code that John Z. had done for the nds2 server. Note for Dave Barker: this is a new daqd that has a new framecpp version string in the full frames, so the checksums are not expected to match between the full frames for h1fw[01] & h1fw2.
We let h1fw2 run overnight. I've attached a plot of the number of re-transmit requests over the last 44 hours (from around the last daq restart). The left side is the old code, the right side is the new. We are still seeing the re-transmits, but the rate is looking better.
