Besty, Oli, Ibrahim, Camilla. Follow on from 91650.
Betsy said that the OSEMINF INMON channels should not change much (over last two years has been < 300 counts) but twice in the last 2 months H1:SUS-ETMX_L1_OSEMINF_UL_INMON has jumped ~2000 counts, both at the time of large earthquakes and when the EX ISI tripped:
Strangely this is not the same quadrant that has been the non responding (91650).
Looking at both of these times, the reason why we moved so much is mostly* due to the OPTICALIGN OFFSETs being turned off.
* ETMX L1 UL DOES still shift a lot when we are in aligned before and after the earthquakes.
On June 24th, at the time where Camilla noted everyone shifting, it was because ETMX had been taken from ALIGNED to DAMPED. DAMPED turns off the OPTICALIGN OFFSETs, so this caused M0's F1, F2, F3 and all of L1's osems to shift. However, looking later on when ETMX is taken back to the ALIGNED state, everyone goes basically back to where they had been before except for L1 UL, which is now over 1900 counts shifted (flag moved out) from where it had been before.
On July 17th, a similar thing happened. ETMX was taken to SAFE, which turned off the OPTICALIGN OFFSETs. A day later it was finally put back into ALIGNED, and once that happened the only osem that read sustantially differently compared to before was L1 UL, which differed by 1100 counts (flag moved out again).
Why did L1 UL shift in the same direction so much both times? Is this related to LL? Find out next time (hopefully)
Looked at DAMP INs for all stages at ETMX during those two earthquake times to get a better idea of how much each DOF shifted due to the earthquakes.
June 24 DAMP INs biggest DOF changes
L1 P: 248 um
L1 Y: 232 um
L1 L: 15 um
July 17 DAMP INs biggest DOF changes
L1 P: 162 um
L1 Y: 128 um
M0 P: 11 um
R0 P: 8 um
L1 L: 8 um
L2 P: 5 um
L3 (OPLEV) P: 6 um
L3 (OPLEV) Y: 6 um
Also, looking at L1 L P and Y over the last few and many years, you can see just how big of a move this was.
