There has been some speculation that the huge glitches in DARM on weekends and in the middle of the night might be beam tube particulate falling through the beam. The absence of correlated events in auxiliary channels (Link) and the lack of saturations, have not helped dissipate this speculation.

I think that we can test the, in my mind unlikely, hypothesis that these huge glitches are particulate glitches by comparing rate variations to what we would expect. If the glitches are produced by a constant ambient rate of particles falling through the beam, then we would not expect large gaps like the one at the beginning of the Aug. 1 run that Gabriele analyzed for the above linked log (see attached inspiral range plot). This is a fairly weak test when applied to this one day: I calculate that the distribution of glitches on Aug. 1 is only 20% likely to be consistent with a constant rate. But perhaps DetChar could strengthen this argument by looking at future variations in rates to test the hypothesis that the rate is constant. I checked that there was no cleaning or wind above 10 MPH for the Aug. 1 period.

If bangs during cleaning on July 30^th had freed up some particulate that then fell over the next few days, and this dominated the glitch rate, than the expected rate would not be constant but exponentially declining starting at the last cleaning. Since the gap was at the beginning of the Aug. 1 run, this would be even more unlikely than 20%. Bubba keeps a record of cleaning so we could also test for exponential declines in rates.

But for starters, maybe DetChar could check for consistency with a constant rate for those glitches that are not associated with saturations, have auxiliary channel signatures similar to known particulate glitches (e.g. Link, and more to come), and happen on days without cleaning (weekends for sure), and with wind under 10 MPH. Since particulate glitches are likely to be an ongoing concern for some, and since glitch rate statistics can be a good discriminant for particulate glitches, I think that it would be worth setting up this infrastructure for rate statistics of unidentified glitches, if it doesn't already exist.