SL presents updates on the results of comparisons between MC simulations and real QCAMi data. One inconsistency that immediately arises is in the adopted trigger threshold, which was ~35 mV rather than ~40 mV. Despite this, real data exhibited +5% of triggered events w.r.t. expectations. Another inconsistency was found in the trigger logic of superpixels, which was affected by typos in the trigger code (diagonal triggers not included). Investigations led to find one malfunctioning superpixel, that was causing spurious triggers of the three adjacent ones. The trigger scan reveals a mismatch between the MC and real data thresholds (~10 mV vs ~20 mV), hinting at the presence of more noise in QCAMi w.r.t. simulations.
- MK asks more details about the malfunctioning superpixel; SL answered that they discovered the issue in February, which was causing the spurious triggers when the adjacent ones were hitting the threshold alone.
- FGS asks if the difference between peak p.e. (usually used in lab data) and mean p.e. (used in sim_telarray simulations) is taken into account in the trigger scan; SL answers that the lab calibration procedure is based on a dynamic scan of the camera response to pulsed light, and asks if there is some further documentation about this peak/mean p.e. mismatch in sim_telarray other than the code manual. FGS replies that he will check.
- FGS also asks why the lab SPE spectrum looks poorly defined; SL answers that this is due to the higher noise in the QCAMi backplane, which will be changed at some point (timeline unknown).