Operators: tavi vziskin vziskin
After Tavi was done with with gain matching I had a smooth shift.
Low BQMs. Few HV trips. Filled to 80 mA dumped at 54 mA. Beam lifetime is 29min. This gives average currrent of 60 mA. However, when I factor in a deadtime, average beam current is a factor of two lower. I noticed that at the start of a fill, liftime is ~50% and ~75% before dump. Thus, lifetime(I) = 1.3-0.01*I, assuming linear dependence in this region. The average current becomes 38 mA.
Also, at this setting the time between fill and dump is about 11 min which allows for an average of 2 target helicity flips (5min). Is this enough not to worry about fill-to-fill systematics? Should we flip more often (at a risk of more dead time)?
BTW, I plotted day-by-day Pe*Pz over the coarse of two weeks of data taking. Please see e-log #20710 for this plot and explonations.
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