Abstract

Abstract

Pisa Meeting on Advanced Detectors / The LHCb VELO Upgrade

The LHCb experiment is about to implement a major upgrade, scheduled to start data taking in LHC Run III. The Vertex Locator (VELO) is the silicon detector surrounding the interaction region. It will be completely replaced with a new light weight pixel detector capable of 40 MHz readout. The upgraded VELO modules will host silicon hybrid pixel tiles read out by VeloPix ASICs. The tiles are mounted onto a cooling substrate composed of thin silicon plates with embedded micro-channels thatallow the circulation of bi-phase CO$_2$. The silicon sensors must with stand an integrated fluence of up to 8$\times 10^{15} 1 MeV n_eq/cm^{2}$, a roughly equivalent dose of 400 MRad. The highest occupancy ASICs will have pixel hit rates of 900 Mhit/s and produce an output data rate of over 15 Gbit/s, with a total rate of 1.6 Tbit/s anticipated for the whole detector. The detectors are located in vacuum, separated from the beam vacuum by a thin custom made foil. The foil will be manufactured through a novel milling process and possibly thinned further by chemical etching. The design of the complete VELO upgrade system will be presented with the latest results from the R\&D and construction.