Present: Francesco, Isabelle, Koun, Eva, Martin, Ricardo, Jonny, Rossella, Ioana

Koun/Ioana/Eva on long term performance of PMTs

The analysis started by being able to reproduce the results from Hernan from the gap in 2012. The first check, comparing the A/P of the year of deployment to 2018 show that about 10% of the PMTs have a decrease of more than 15%. The A/P time profiles are fitted with an exponential convoluted with an anual modulation similar to the previous studies. While for the time interval between 2010-2012 the results are similar, including the last period the  parameters are quite different. The analysis is still preliminary, and a better selection criteria of good-behaving PMTs is under study. The second part of the talk delaed with raining PMTs, slelected based on the RMS of the distributions. The number of raining PMTs in 2018 in the field is around 100, and it seems that each year about 20 PMTs become raining.  A few PMTs show large RMS for more than 10 years. Eva is interested in looking at the effects of the new UUBs on these variables and collaboration with ULB is starting.

Isabelle: Do you plan to get other variables to be able to have a better selection for raining like it was done in the past? Koun/Ioana: Not sure.

Isabelle: Have you considered fiting just the last period of time? Koun: Yes, this is the plan (as also suggested by Hernan).

Isabelle: Are you planning to include the last winter in your analysis as it was a hard winter in Maargue? Koun: Yes. I have just downloaded the mc files until today today.

Ioana: How are exactly the raining PMTs fixed? Ricardo: They are fixed in the field, using an extra cable for the grounding of the PMT bases. Ioana:  Are the ones that are for more than 10 years raining not easy accesible (around 70)? Ricardo: Not sure, the PMT fixes does not depend on the years they have been raining.

Ioana: A/P depends on the HV of the PMTs? Isabelle: It should not. Ricardo: Small dependency that is not understood is seen.

Ioana: Why when one of the PMTs is masked there is a change in A/P. Ricardo: The signals that enter in the Area and Peak calculations are not exactly the same, the T1 definition changes.

===== Discussion =====

Ricardo: new UUBs will be installed soon.

Martin: the 20 stations that showed certains peaks (see previous meeting) are basically due to different FE.

Francesco/Lorenzo's email:In the past days Violet has worked to a third version of the Aerosol DB (bug fix, see past calls). The production is about to finish.

Concerning FD shift reports: Francesco, Mariano and Lorenzo were in contact in the past days to finalize the transition of the machinery for the quasi-on-line analysis to the new virtual machine. It has been setup in Malargue with more recent offline/externals.Mariano worked to move and update the scripts. We are on time with shift reports now.

One question still remains: Have the mirrors been cleaned :)? (Jonny had a bad connection)

We will decide when to have the next meeting (in 2 weeks the UHECR symposium is taking place so maybe we will postpone the next meeting by one week).