Speaker
Kelvin Mei
(Princeton University)
Description
We report on the first LHC collision data taken with a 20 degree wedge of
the CMS Hadron Calorimeter Endcap instrumented with SiPMs and the QIE
ASIC version 11 front-end chip.
Operational experience is reported on temperature and gain stability of the
SiPMs. The performance of the front-end ASIC and digital readout are also
presented. The light loss from the darkening of the CMS HCAL endcap
scintillator is shown to be mitigated by the increased PDE of the SiPM and
higher overall S/N of the front-end upgrade. We compare the performance of
the Phase I front-end upgrade electronics with the previous HPD-based
front-end system performance with LHC collision data collected in 2017.
