Turbo pump was started yesterday at 16:22 local time, pressure this morning had reached 3.4x10^-03 torr, no update on current pressure since CC has not turned on yet, but pump continues to pump.
Started turbo at 16:25 local time, about 30 min. later I started the CC, we see a pressure of 1.30x10^-05 torr.
Attached are plots of dust counts > .5 microns. I have also included plots of the mode for the dust monitors at end Y to show when they were moved.
Dan tested beam diverter and everything worked including the motor and the two reed switches.
That's strange as one of the two reed switches was stuck before, but somehow it's unstuck. Anyway it's good.
I'm curious to get my hands on this Beam Diverter, after my experience with building five of them. For me, the Sensor Magnet's polarity seem to affect the functionality for the Reed Switches (Chirs Guido mentioned the position of this magnet was more the issue for him).
Dave restarted all the models of h2seib6. Gerardo moved dust monitor 2 in the end Y LVEA into the clean room over BSC 6. The IOP watchdogs for SUS BSC6 were tripped (in chamber work)
Today, we finished fixing the PUM (L2) LR magnet/flag. We then verified that the suspension was free of any mechanical rubbing (many head to toe inspections) and adjusted all OSEMs to nominal settings, accounting for buoyancy. So, we are ready for TFs on this guy.
Summary:
The power supply and fan issues with the i/o chasses could be solved with a new power supply producing smaller magnetic fields (being planned by CDS), routing cables away from power supplies, and a separate supply for the fans. The strongest magnetic field coupling sites to the OSEM read back channels were the cable connectors to the chasses that the signal passes through and not boards such as the a to d board. However, since the cables pass close to the power supply, the dominant coupling for the power supply fields was to the cables instead of the connectors at their ends. The separate issue of the fan frequencies showing up in channels can be solved by using an external power supply: the remaining coupling (from magnetic fields) when using a separate supply was measured here to be down by at least ten.
Power supplies in the I/O chasses:
In a previous log I reported that magnetic fields from the I/O switching power supply were strong enough to couple into channels at an unacceptable level (here). Since then, I have investigated the magnetic field coupling sites to see if there were any coupling sites that could be mitigated.
I looked for magnetic field coupling sites to one of the UIM OSEM readback channels for ITMY. I used a centimeter scale coil and slowly scanned circuit boards etc., while monitoring the coupling on a screen. The strongest coupling that I found was to the cable connectors to the UIM coil driver, the anti-aliasing module and the I/O chasis. The coupling to the connectors was stronger than the coupling to the a to d board, or any other location inside the coil driver or I/O chassis or along the cables. Note that this is only a test of coupling to the read back channel: I have not fully tested coupling of rack magnetic fields to the coil actuators.
Notwithstanding that the strongest coupling site was to the cable connectors, the dominant coupling site for the fields from the I/O chassis power supply was to the cables themselves because they pass so close to the power supply. Figure 1 demonstrates cable coupling, showing that when the cable into the UIM coil driver was about 10 cm from a field generator set on the I/O chassis power supply, the injected comb showed up strongly on the channel, but much less so when the cables were moved about 40 cm away from the field source, with no other changes.
Fans in the I/O chasses:
I noted in a recent ilog (here) that i/o chasis fan frequencies showed up in the channels passing through the chasis. When the fans were run on a separate power supply, the coherence was lower, but because of time constraints and dtt crashes, I was not able to run long coherence measurements to make sure that the coupling was much lower. Figure 2 shows the results of a recent 79,000-average coherence measurement, and the fan peaks appear to be showing with a low level of coherence. The plot suggests that the coupling of the fans to the i/o chassis channels is down by a factor of about 10 when the fans are run on a separate power supply.
For this reason, I think that running the fans on a separate power supply will be sufficient. So, to solve the issues I have raised recently, the i/o chasis power supplies should be replaced and the fans should run on independent supplies. There is a chance that power supply ripple from the fans would not be a problem with the new power supplies. I have not tested this.
Relocated the Y-End station dust monitor #2, it is set inside the BSC06 clean room, it is next to the SE pier. However it needs to move closer to where the action is, but we need a longer cable to accomplish that, yes we are looking for a longer cable. Dust monitor #1 remains located West of the iLIGO racks inside one of the cleanrooms.
We found a cable, thanks Richard, so we re-relocated the dust monitor (#2), now the location is by the NW pier of BSC06.
The dust monitor labeled 'L' is at location 1. The dust monitor labeled 'M' is at location 2.
Attached are plots of dust counts > .5 microns.
See Betsy's closeout checklist for the latest updates. https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=2848
Since Betsy was working with Derek on Triples gluing stuff, I was on my own for much of the day. I rediscovered that working on a monolithic Quad is rarely a one-person job, especially in chamber with TMS as its neighbor. I began by attempting to remove the TFE caps that were on many of the spherical tip and silica tip EQ stops. After cautiously removing as many as I could confidently do by myself, I was left with 4 caps on the underside of the top masses that were inaccessible by me solo due to limited access from the reaction side of the Quad. These 4 caps require that someone with skinnier arms than mine reach through the Quad between the top and UI masses to grip the TFE cap from the inside while simultaneously working the screw from the outside to thread the cap off. With a few spare minutes, Betsy helped me remove these last 4 caps. Even with 2 people, we found this activity less than relaxing. Note for future builds: Remove these caps before the monolithic is installed (since the majority of the clamping/unclamping is done by that point, the particulate issues these hoped to resolve is less of a concern).
After the caps were removed, we noticed that one of the flags on the penultimate mass was dislodged from its steel disc baseplate, and that the magnet on the end of it was not seated correctly. Betsy returned to her work with Derek, so I was on my own again. To remedy this required the removal of the AOSEM opposite the flag in question in order to grasp the flag. However, grasping the flag to remove/realign it is not trivial either. This requires the use of a set of 10" long tweezers which must be inserted through the AOSEM hole (~1" diameter) in the PenRe to gingerly grab the assembly so as not to drop either of the 2mm x 6mm magnets of either end. Again, due to access issues to the reaction side, I could not see the flag from this side. To complete this simple task, 2 people will also be required: one to manipulate the tweezers and one to view/guide from the main chain side by looking through the penultimate mass, which luckily is transparent glass. After bumping my head for the third time attempting the solo version of this task, I decided to move on (Note to TMS designers: much much larger chamfers on parts would be greatly appreciated). I then installed the last of the sleeve screws that had been in use at BSC8 until recently. Currently, the Quad is not fully suspended due to the PenRe being locked until the flag repair is complete.
Work in and around BSC6 throughout the day. There were a few dust level alarms for "DST1_3" which is one of the two located in the End-Y VEA (the exact location of this dust monitor is not clear from the medms). H1 PSL work in the LVEA. No machine reboots to report.
Condition of chambers was documented. HAM4 Support Tubes and bellows were inspected then bellows were vacuumed and the support tubes "picked". Support tubes will be wrapped and bellows protection installed.
Joe D. and Jodi re-cleaned the two high quality viewports from the south door. Cheryl inspected them and they are ready for re-installation. The crew finished pulling the iLIGO flooring and installed the aLIGO flooring that is electropolished and qualified for UHV service. In removing the remainder of the iLIGO flooring this morning, Mark L. came upon a mystery: two unexpected holes in the longest plank of the flooring. Attached please see some pix. As you can see from the size discrepancy, these are not the normal holes for BSC flooring. All LIGO-ites questioned deny drilling/tapping the holes. For now, we will chalk it up to the "little green men from outer space" but it is not comforting to have holes appear in structures without any notice or agreement. >-(
There were some dust monitor alarms triggered during the night in the End-Y VEA. The attached plot shows there were elevated levels of dust counts that are coherent with increased wind speeds. This suggests spurious wind currents leaking into the VEA could cause dust particles to swirl around, increasing the dust count levels.
I, Alberto and MichaelL unmounted the eLIGO L1 OMC (that was used for H1 squeezing experiment) from the optics cart in the H2 PSL ante-room and moved it to the H2 PSL table. The OMC was dogged down and wrapped by foils.
The cart was moved to the outside and put in a clean room near by.
FYI another eLIGO OMC (original H1 OMC) is in a protective cage in a shipment box in the optics lab.
Pumping was stopped overnight, system is not designed to run unattended, will restart early tomorrow. Pressure at 1.74 torr.
Following is the list of items that need to be completed (in roughly the order below) before we can close this chamber. Some of the items have been finished and are still on the list as markers for redlining the installation procedure. Please add a comment if I have missed any steps 1) Electrical grounding checks - DONE 2) IAS SEI alignment complete, ISI & HEPI floating - DONE 3) IAS ETMy alignment Round 1 - DONE 4) TMS alignment - DONE 5) ESD continuity check 6) Clamp ETMy EQ stops 7) Reapply FirstContact to ETMy-HR and ERM-AR 8) Swap Flooring - Waiting for FTIR on new set, can slip down list but not beyond 14a. 9) Viewport in-situ cleaning (or swap if deemed necessary) 10) TMS OSEM alignment 11) Close the ring heater and set fiber guard to "nominal" position 12) Unlock ETMy, remove all TFE except TM line stops, and physically check for rubbing as per T1200213 (still drafting) 13) ETMy BOSEM alignment, factoring in buoyancy as per T1100616 14a) ETMy testing (See Phase 3a G1100693) 14b) IAS ETMy alignment again (if testing showed interference and suspension was adjusted to fix) 15) Repeat step 14 until all Phase 3a testing is complete - usually done in 3 rounds in order to clear all issues. Note, IAS requires removal of ETMy-HR FC completely. 16) TMS alignment check if needed 17) Lock down flooring nuts if loose 18) Set all EQ stops as per M1100256 19) Final FirstContact cleaning if needed 20) Remove TM line stops 21) Take pictures and count number of PEEK clamps 22) Set witness plates 23) Remove all tools Shut the doors.
The good news is we're working down the list. The bad news is, I added a few more items to the list. Edited to reflect actual order:
1) Electrical grounding checks (moved down the list since it was DONE on the test stand, not on the chamber)
2) IAS SEI alignment complete, ISI & HEPI floating - DONE
3) IAS ETMy alignment Round 1 - DONE
4) TMS alignment - DONE
5) TMS OSEM alignment - moved up list since DONE
6) ESD continuity check
7) Clamp ETMy EQ stops - DONE
8) Reapply FirstContact to ETMy-HR and ERM-AR - (did not so ETM-HR since sheet was still somewhat intact) DONE
9) Swap Flooring - Waiting for FTIR on new set, can slip down list but not beyond 14a.
10) Viewport in-situ cleaning (or swap if deemed necessary)
11) SEI Electrical grounding checks
12) SUS Electrical grounding checks
13) Close the ring heater and set fiber guard to "nominal" position
14) Unlock ETMy, remove all TFE except TM line stops, and physically check for rubbing as per T1200213 (still drafting)
15) ETMy BOSEM alignment, factoring in buoyancy as per T1100616
16a) ETMy testing (See Phase 3a G1100693)
16b) IAS ETMy alignment again (if testing showed interference and suspension was adjusted to fix)
17) Repeat step 16 until all Phase 3a testing is complete - usually done in 3 rounds in order to clear all issues. Note, IAS requires removal of ETMy-HR FC completely.
18) TMS alignment check if needed
19) Lock down flooring nuts if loose
20) Set all EQ stops as per M1100256
21) Final FirstContact cleaning if needed
22) Remove TM line stops
23) Take pictures and count number of PEEK clamps
24) Set witness plates
25) Remove all tools
Shut the doors.
Update to closeout checklist:
1) Electrical grounding checks (moved down the list since it was DONE on the test stand, not on the chamber)
2) IAS SEI alignment complete, ISI & HEPI floating - DONE
3) IAS ETMy alignment Round 1 - DONE
4) TMS alignment - DONE
5) TMS OSEM alignment - moved up list since DONE
6) ESD continuity check
7) Clamp ETMy EQ stops - DONE
8) Reapply FirstContact to ETMy-HR and ERM-AR - (did not so ETM-HR since sheet was still somewhat intact) DONE
9) Swap Flooring - Waiting for FTIR on new set, can slip down list but not beyond 14a. DONE
10) Viewport in-situ cleaning (or swap if deemed necessary) IN PROCESS
11) SEI Electrical grounding checks
12) SUS Electrical grounding checks
13) Close the ring heater and set fiber guard to "nominal" position
14) Unlock ETMy, remove all TFE except TM line stops, and physically check for rubbing as per T1200213 (still drafting) DONE (PenRe has be relocked due to flag repair) Also, 1/4-20 x 3/4" vented screws installed for sleeve (these were overlooked in the making of this list).
15) ETMy BOSEM alignment, factoring in buoyancy as per T1100616
16a) ETMy testing (See Phase 3a G1100693)
16b) IAS ETMy alignment again (if testing showed interference and suspension was adjusted to fix)
17) Repeat step 16 until all Phase 3a testing is complete - usually done in 3 rounds in order to clear all issues. Note, IAS requires removal of ETMy-HR FC completely.
18) TMS alignment check if needed
19) Lock down flooring nuts if loose
20) Set all EQ stops as per M1100256
21) Final FirstContact cleaning if needed
22) Remove TM line stops
23) Take pictures and count number of PEEK clamps
24) Set witness plates
25) Remove all tools
Shut the doors.
Update to closeout checklist:
1) Electrical grounding checks (moved down the list since it was DONE on the test stand, not on the chamber)
2) IAS SEI alignment complete, ISI & HEPI floating - DONE
3) IAS ETMy alignment Round 1 - DONE
4) TMS alignment - DONE
5) TMS OSEM alignment - moved up list since DONE
6) ESD continuity check
7) Clamp ETMy EQ stops - DONE
8) Reapply FirstContact to ETMy-HR and ERM-AR - (did not so ETM-HR since sheet was still somewhat intact) DONE
9) Swap Flooring - Waiting for FTIR on new set, can slip down list but not beyond 14a. DONE
10) Viewport in-situ cleaning (or swap if deemed necessary) DONE
11) SEI Electrical grounding checks
12) SUS Electrical grounding checks
13) Close the ring heater and set fiber guard to "nominal" position DONE, AS MUCH AS IT CAN BE
14) Unlock ETMy, remove all TFE except TM line stops, and physically check for rubbing as per T1200213 (still drafting) DONE (PenRe has be relocked due to flag repair) Also, 1/4-20 x 3/4" vented screws installed for sleeve (these were overlooked in the making of this list). DONE
15) ETMy BOSEM alignment, factoring in buoyancy as per T1100616 DONE
16a) ETMy testing (See Phase 3a G1100693) DONE
16b) IAS ETMy alignment again (if testing showed interference and suspension was adjusted to fix) DONE
17) Repeat step 16 until all Phase 3a testing is complete - usually done in 3 rounds in order to clear all issues. Note, IAS requires removal of ETMy-HR FC completely. DONE (PENDING FINAL SET OF TFS TODAY)
18) TMS alignment check if needed IN PROCESS
19) Lock down flooring nuts if loose
20) Set all EQ stops as per M1100256 DONE
21) Final FirstContact cleaning if needed
22) Remove TM line stops
23) Take pictures and count number of PEEK clamps
24) Set witness plates
25) Remove all tools
Shut the doors.
