Today we finished up the ETMx in-chamber activities adn closed the door. Sequence of events:
Filiberto checked for TMS QPD cable grounds at the feedthru. All ok there. (Actually did this yesterday afternoon.)
Kyle and Gerardo finished the port work (that was scheduled in the original vent plan).
Fil check the ESD pinout with aid from an "inside" guy multiple times in order to make clear the understanding of the pins on the air-side of the feedthru.
Jim unlocked the ISI.
Performed the discharge procedure on ETMx as per T1500101 - again, this took around 1 hour.
Swapped the vertical witness plates (1" and 4") that were mounted on the QUAD structure. 1" optic vertical on floor is now: SN 242.
Removed all equipment and re-suspended lower masses.
Dust counts taken throughout. Counts were nomnally 30-200 counts in all sizes of particles with few bursts up to 500 in th 0.3um size once in a while when 2 or more people were moving in chambelr. Counts were zero or 30 (max when entering chamber after lunch or in morning.
Measured ETMx main and reaction chain P and V TFs. All looked healthy with purge air on and soft cover over door.
Door being put on.
Checked EQ (earthquake) stops (Note this is the same as we found/set on ETMy):
Barrels of ERM ~2mm
Barrels of ETM ~1.5-2mm
12 o'clock stop ~3+mm
PenRe barrel ~1.5-2mm
PUM barrel ~2mm
All face stops 1-1.5mm
Purge air has been valved off.
Dang it - I didn't relogin - Betsy posted this, not Corey.
Discharge of ETMx WBSC9 (in chamber)
Using the ETM / ERM Gap discharge procedure https://dcc.ligo.org/LIGO-T1500101 we discharged the optics in chamber at ETMx. As before the procedure includes a swing back of the ERM i.e. an increase in the gap between the optics. Using the electrometer https://www.trifield.com/content/ultra-stable-surface-dc-volt-meter/ mounted centrally (on an X brace) 1" from the back of the ERM (i.e. between the ERM and TMS) we measured the following voltage: -
Note: - Prior to starting we zeroed the electrometer (10:28 am) with the cap on.
1) At start (after electrometer was mounted 1" from back of ERM and prior to swing back) = 21.9 V (10:30 am)
Note: During work on pinning ESD the reading went to = 17.2 V. Then the locking of the sus took it up to = 25.9 V. More to follow.
2) During mounting of swing back tooling = 26.6 V.
3) Electrometer was moved 5mm away from the ERM to allow for space during swingback = N/R V.
Note: Jim came into chamber to un-lock ISI. The ESD was re-pinned twice at this time. At this point (for saftey) we took off electrometer.
4) (Once electrometer was back on & Jim was finished) During swingback went up to peak of = 18.9 V.
5) Once Electrometer was moved back to being 1" from optic (and in chamber team in home position) = 21.1 V.
6) At this pont we broke for lunch. Once everyone out the chamber and soft door cover on = 20.6 V.
7) When we came back from lunch (2 hour later) = 9.5 V.
8) (When Danny entered chamber just after) the soft door cover came off = 8.8 V (1:38 pm)
Note: At this point humidity was 26%.
9) After completion of ETM / ERM Gap discharge procedure (inc 5 min after home) = 4.0 V (and decaying).
10) After swing back of ERM (back to original position) and with electrometer reset to being 1" from optic = 4.9 V
Note: - At this point team started to suspend the chains and run (basic) transfer functions on both the main chain and the reaction chain. We left the electrometer in place during this time.
11) At end (prior to doors on) at pm = 3.6 V *.
12) Final number - At the end we put the cap back on the electrometer and it was now reading 1.4 V. Therefore we are calling the final number = 2.2 V (i.e. 3.6 V - 1.4 V).
Note: - The final number was not decaying as per previous on Y end. More to follow on this. Data was collected over 10+ minutes.
Note: - Humidity was 28% just before doors on. Doors were in place at around 4:03 pm.
Kate Gushwa, Gary Traylor, Danny Sellers, Travis Sadecki, Betsy Weaver and Calum Torrie