Mr Jens Kroeger (University of Heidelberg & CERN)
The physics aims at the proposed future CLIC high-energy linear e-e+ collider pose challenging demands on the performance of the detector system. Precise hit-time tagging with ~5 ns resolution is required for the vertex and tracking detectors, to mitigate the impact of beam-induced background on the measurement accuracy. Moreover, a low mass of ~0.2% X0 per layer for the vertex and ~1% X0 per layer for the tracker is needed, combined with a single-plane spatial resolution of a few micrometers. To address these requirements, an all-silicon vertex and tracking system is foreseen at CLIC. To this end, a broad R&D program on new silicon detector technologies is being pursued. For the ultra-light vertex detector, different small pitch (25 um) hybrid technologies with innovative sensor concepts are explored. A dedicated 65 nm readout chip (CLICpix2) has been developed and interconnected via fine pitch bump-bonding to thin planar sensors. Furthermore, alternative interconnects such as bonding using anisotropic conductive films (ACF) are explored. Various Silicon On Insulator (SOI) test chips are also under study. For the large-scale silicon tracker, fully monolithic CMOS technologies are considered. CMOS sensors with a large collection electrode have been extensively studied in various test-beam campaigns. Based on 3D TCAD simulations and previous test results, innovative concepts for CMOS sensors with a small collection electrode have been developed and implemented in various prototype chips targeting CLIC and other future projects. The CLICTD tracker prototype chip has recently been produced using two variants of a modified 180 nm CMOS process with a high-resistivity epitaxial layer. The design includes an innovative sub-pixel segmentation scheme and first samples are currently under evaluation. To predict and further optimise the performance of the various prototype technologies, a fast and versatile Monte Carlo Simulation Tool (Allpix-Squared) has been developed. This contribution gives an overview of the R&D program for the CLIC vertex and tracking system, highlighting new results from measurements and simulations of recent prototypes.