Status & Challenges of Tracker Design for FCC-hh

A 100 TeV proton collider represents a core aspect of the Future Circular Collider (FCC) study. An integral part of this project is the conceptual design of individual detector systems that can be operated under luminosities up to $3\times10^{35} \mathrm{cm}^{-2} \mathrm{s}^{-1}$. Compared to HL-LHC scenario, one of the key limitations in the design arises from an increased number of pile-up events O(1000), c.f. O(140) at HL-LHC, making both particle tracking and identification of vertices extremely challenging. This paper reviews the general ideas that conceptually drive the current tracker/vertex detector design for the FCC-hh (proton-proton). These include material budget, detector granularity, pattern recognition, primary vertexing/pile-up mitigation and occupancy/data rates. Finally, the limits of current tracker technologies and requirements on their future progress, i.e. the dedicated R&D, are discussed.