The ePIC Silicon Vertex Tracker IB-OB: Design and thermal-mechanical simulations

Abstract

The future Electron–Ion Collider (EIC) will offer a unique opportunity to explore the parton distributions inside nucleons and nuclei thanks to an unprecedented luminosity, a wide range of energies, a large choice of nuclei and polarization of both beams. The Electron–Proton/Ion Collider (ePIC) detector will be capable of precise determination of the position of primary and secondary vertexes, essential e.g. for the identification of charm hadrons, giving access to the gluon distribution inside hadrons. This measurement capability is achieved with a Silicon Vertex Tracker (SVT) placed as the innermost device in the ePIC experiment. The SVT Inner and Outer Barrel (IB, OB), developed by a collaboration of Italy-UK-USA institutes, provide five detecting layers made of silicon detectors, using the 65 nm Monolithic Active Pixel Sensor (MAPS) technology with stitching, pioneered by the ALICE collaboration for the Inner Tracking System 3 (ITS3) upgrade. The IB main focus is on vertexing performance. It is made of three layers of wafer-scale sensors bent to a cylindrical shape. The OB, composed of two layers, mainly contributes to the particle momentum measurement and it is equipped with a smaller version of the IB sensor mounted in a typical stave configuration. This paper will present the design of SVT Inner and Outer Barrel and the first Finite Element Analysis (FEA) simulations for mechanical and thermal studies.