Prototyping of hybrids and modules for the forward silicon strip tracking detector for the ATLAS Phase-II upgrade

For the High-Luminosity upgrade of the Large Hadron Collider an increased instantaneous luminosity of up to 7.5 ⋅ 10³⁴ cm⁻² s⁻¹, leading to a total integrated luminosity of up to 3000 fb⁻¹, is foreseen. The current silicon and transition radiation tracking detectors of the ATLAS experiment will be unable to cope with the increased track densities and radiation levels, and will need to be replaced. The new tracking detector will consist entirely of silicon pixel and strip detectors. In this paper, results on the development and tests of prototype components for the new silicon strip detector in the forward regions (end-caps) of the ATLAS detector are presented. Flex-printed readout boards with fast readout chips, referred to as hybrids, and silicon detector modules are investigated. The modules consist of a hybrid glued onto a silicon strip sensor. The channels on both are connected via wire-bonds for readout and powering. Measurements of important performance parameters and a comparison of two possible readout schemes are presented. In addition, the assembly procedure is described and recommendations for further prototyping are derived.