- Broida 3302
- FPix Seminar
The task of the CMS pixel detector is to provide high-resolution 3D space points required for charged particle track pattern recognition and bottom quark tagging. Situated closest to the interaction point just outside the beam pipe, the pixel detector has to be able to cope with the high data rates and radiation doses. The Phase-0 pixel detector was designed for the LHC nominal luminosity of 10^34 cm−2 s−1 and performed excellently during Run 1 and early Run 2 data-taking in 2015 and 2016. However, the LHC has exceeded its design luminosity in 2016 and the phase-0 detector suffered from dynamical inefficiencies, resulting in data loss and degraded tracking and vertex reconstruction performance. To cope with the more challenging environment, CMS planned a phase-1 upgrade of the pixel detector, which is expected to perform well until the High Luminosity LHC. The new forward pixel detector was constructed by US CMS institutions during 2015-2016 and installed in CMS in early 2017. The detector was quickly commissioned and transitioned smoothly to data-taking. In this talk, I will discuss the improved detector design as well as experiences from constructing and commissioning the forward part of the detector. I will also discuss the DC-DC converter failures observed last year and where we stand today in understanding this issue.