The original design goal of the LHC was to operate at 1 × 10 34 cm -2 s -1 with 25 ns bunch spacing, where approximately 25 simultaneous inelastic collisions per crossing ("pile-up") occur. With the upgrade of the accelerators, the luminosity and pile-up will more than double. The current pixel detector is crucial to charged particle tracking, but was not designed to perform effectively in such collision conditions and the physics program of CMS would suffer as a result. We propose to replace the current pixel tracker with a new high efficiency and low mass detector with four barrel layers and three forward/backward disks to provide four-hit pixel coverage out to pseudorapidities of ±2.5. This new detector will meet or exceed the original design specifications in these high luminosity environments. In this report, we provide details on the design, construction and installation of the upgraded pixel detector as well as estimates of its expected performance.
Cover Design
S. Cittolin
AcknowledgmentsWe would like to thank the technical staff from the various institutions for the design, R&D and testing of the many components of this upgrade.We also wish to thank the LHCC for their oversight and crucial advice during the development of the the pixel upgrade project. The important feedback from following CMS internal reviewers greatly helped in the development of this technical design report: D. Contardo, S. Dasu, S.C. Eno, P. Giacomelli, G. Gomez Ceballos, E. Halkiadakis, C. Hill, M. Klute, S. Lowette, M. Mannelli, S. Nahn, I. Shipsey, D. Stuart, S. Tkaczyk and J. Varela.A special thanks goes to the CMS Secretariat, in particular Anastasia Dolya, for their tireless support during all stages of the project. We also acknowledge the warm support received from the CMS management team and computing project.Finally, we dedicate this technical design report for the upgrade of the pixel detector to the memory of our two colleagues and friends: