(The log is messing up with me and my entry from last night got deleted this morning when I tried to add a plot - new failure mode for me)

Commissioning Team 

Sensitivity status

We achieved  36 Mpc  on Friday, improving the sensitivity over the previous day by: 
Adding cut-offs in the ASC DHARD dofs
Switching off completely the ETMX ESD driver after switching to the low noise ESD on ETMY
Adding MICH and SRCL feed-forward subtraction (still not optimal, but somewhat effective, see  Evan's entry 
We had one single lock lasting for about 2h, while making measurements/tests, so data are not clean (see range summary). We collected only a few minutes of clean data (March 27, 23:50-23:55 UTC, if I remember correctly - Evan please check this). The second plot shows the progression of sensitivity this week, starting from 16 Mpc (not shown in this plot), to the red curve from last night. 

We noticed that the high frequency part of the sensitivity is slightly worse than the previous day, without any apparent reasons beside different initial alignment. 

Also, we learned a few things about data quality based on the analysis of the long lock from the night before. Sheila and Kiwamu tracked down the  ISS glitching problem , which is now fixed (not permanently - need some automatic way of keeping the ISS happy). Also, Josh et al. pointed out that the long lock the other night showed  ETMY L3 DAC glitches , and this needs to be fixed. This adds to the already reported  whistles , that also need attention.


Other news

Daniel and Evan attempted to make the ETMX ESD driver remotely switchable in the afternoon, but this first attempt failed (not a big deal yesterday as we had only one long lock)
On a positive side, adding a digital limiter to the ESD correction signal seems to have solved the problem with the EY ESD driver switching off after each unlock (see   this entry and comments  


Problems in the evening

The last thing we wanted to get done on Friday to conclude this great week was to close the beam diverters on the transmon. At the same time, some of the low noise steps done outside the Guardian (like the BS M2 coil driver switch to low noise) were added to the Guardian code. These two (apparently innocent) goals created a couple of unexpected problems (see  entry 17547  and  entry 17548 ), but I believe at this point Sheila and Jamie fixed both. Also, the wind started blowing hard right after dinner (see  Dan and Evan's entry ). 

For the records, the prophetic words of wisdom that Daniel told us right after the 36 Mpc lock were: "Go home, it can only go down-hill from here".