Camilla, Ibrahim, Oli
After doing multiple tests it looks like ETMX is no longer rubbing. We will be checking again at the beginning of next week once we pump back down to higher vacuum to be certain.
After EX was burped the first time and the TMDS team may or may not have discharged anything, I ran some ETMX M0 and R0 transfer function measurements that showed that we were no longer rubbing. The M0 measurements were taken with the OPTICALIGN OFFSETs OFF since I didn't want to saturate the DACs. However, I later took an L measurement with the OPTICALIGN OFFSETs ON (just lowered the excitation amplitude), and these also looked good.
We also did tests where we put offsets into the L1 COILOUTF filter banks, in the M0 TEST filter banks for L and V, and toggled the OPTICALIGN OFFSETs. No rubbing was seen during any of these movements. All L1 osems moved in ways that made sense. For example, when putting the offsets in each L1 osem, the osem with the offset moved the most, and the osem diagonally opposite moved the least, with the other two osems moving somewhere in between. Here's a table Camilla made to illustrate how much each osem moved when we drove through each osem on L1 and through L on M0.
So we're pretty sure that however we had been stuck, that is no longer happening. We do want to note however, that we are not back at the same place we were before the earthquakes, so we have not recovered that alignment. Comparing before the earthquakes to a couple hours ago when we were at 1e-8 Torr and ETMX was aligned, UL still differs in alignment by thousands of counts, which is 100 um. M0 P differs by 81 urad, R0 P by 56 urad, L1 L is 22 um, P is 425 urad, and Y differs by 355 urad.
M0 rubbing check on Sept 01: 91783
Transfer function timeline:
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Burp 1 and TMDS attempt 1
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| Stage | Meas Name | DOFs | Pressure (Torr) |
OPTICALIGN OFFSETs
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| M0 | 2026-09-03_1900 (r13137) | L,T,V,R,P,Y | 0.1 to 1E-8 | OFF |
| M0 | 2026-09-03_2200 (r13137) | L | 1.00E-08 | ON |
| R0 | 2026-09-03_2215 (r13138) | L | 1.00E-08 | -- (no offsets) |
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Burp 2 and TMDS 2
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| R0 | 2026-09-03_2300 (r13138) | L,T,V,R,P,Y | 8 | -- (no offsets) |
| M0 | 2026-09-03_2315 (r13137) | L,T,V,R,P,Y | 8 | ON |
