I've been investigating the range drops associated with loud (SNR > 1000) glitches.

During ER7, these were thought to be due to particles falling through the beam (see alogs on "dust glitches" 20276, 20354, 20355, 20328, 20395, 20484).

In ER8, we are still seeing loud glitches associated with range drops, however now there are also saturations on SUS ETMY (see alogs 19939, 19947, 20071, 20612, and almost every Ops summary since August 17).

Every Omicron trigger with SNR > 1000 (and most of those with SNR 100 – 1000 as well) is simultaneous with a range drop and an ETMY saturation during the 92 hours from September 3 - 6.

By contrast, none of the SNR > 1000 triggers from June 9 - 11 are associated with ETMY saturations.

On the other hand, OmegaScans and timeseries plots of the ER7 and ER8 glitches look similar, suggesting that all the glitches may be related.

So, if there are two distinct glitch classes, the "dust glitches" appear to have stopped occurring.

Or, if all the glitches have the same cause, then something seems to have changed to make ETMY more sensitive to them.

Has anything in the control system changed in a way that could lead to larger signals appearing on the ETMs for the same ‘glitch stimulus’?

See plots attached, and PreO1WorstGlitches page for more details.