The Silicone Tracking System (STS) of the future CBM experiment is a unique detector aiming to cope with charged particle tracks and momentum measurement at unprecedented heavy-ion beam-target interaction rates up to 10 MHz. The detector design combines features low material budget down to 2% of radiation length, radiation hardness up to 10^14 n_eq/cm^2, and single-point resolution of ~30 μm which results in the momentum resolution of about 1.5%. The essential property of STS is a free-streaming triggerless read-out which allows to independently obtain data from about 1.8 million silicon microstrip channels with timing better than 5 ns along with charge measurement. The online reconstruction algorithms provide the real-time event building and selection. Such challenging requirements to the detector are dictated by the physics program of CBM: to study strongly interacting matter at high net-baryon densities with multi-strange particle yields and other rare observables.
The CBM-STS team has produced the mSTS detector, consisting of 11 prototype STS detector modules. It was operated in high-intensity heavy-ion beam from the GSI-SIS18 accelerator as a part of the mCBM demonstrator experiment.
From early 2022 the STS assembly centers start the pre-series production of the final-shape detector components. The detector construction is expected to be finished until the end of 2024.
In the presentation, the current prototypes and the detector under preparation will be overviewed.