The CMS Phase I pixel detector

The CMS silicon pixel detector allows for precise track parameter measurements and vertex reconstruction. The current detector is designed to operate at a maximum luminosity of 1$\times$10$^{34}$ cm$^{-2}$ s$^{-1}$. The Phase 1 pixel upgrade is planned to meet or exceed the necessary performance at the expected peak luminosity of 2$\times$10$^{34}$ cm$^{-2}$ s$^{-1}$ of the updated accelerator in an environment where there are many interactions per beam crossing. The new low mass pixel detector will have four barrel layers and three forward/backward disks to provide four pixel hits on tracks. Radiation damage, rate limitations, and performance are being simulated and measured.