Plans and Status of the Phase~I Upgrade of the CMS Pixel Tracker

The silicon pixel detector is the innermost component of the CMS tracking system and plays a crucial role in the all-silicon CMS tracker. While the current pixel tracker is designed for and performing well at an instantaneous luminosity of up to $1\times10^{34}$\,cm$^{-2}${s}$^{-1}$, it can no longer be operated efficiently at significantly higher values. Based on the strong performance of the LHC accelerator, it is anticipated that peak luminosities of two times the design luminosity are likely to be reached before 2018 and perhaps significantly exceeded in the running period until 2022, referred to as Phase~I. Therefore an upgrade is planed for the year-end technical stop in 2016: With a new pixel readout chip (ROC), an additional fourth layer, two additional endcap disks, and a significantly reduced material budget the upgraded pixel detector will be able to sustain the efficiency of the pixel tracker at the increased requirements imposed by high luminosities and pile-up. In this contribution, the new design of the pixel detector along with its expected physics performance will be presented. Also, the results of first ROC beam tests will be reported