Slide 12 of 17
Notes:
Even so collisions were never achieved beam-gas collisions could be used to test the readout of different detectors.
Here the beam going from south to north (BLUE) hit patterns in the beam-beam Cherenkov counter. Green indicate active red a bit.
Signalks are also seen in the Zcal with these two being the future interaction and centrality trigger.
Because of the high background due to not optimized beams only a small fraction of the detector was operated.
