The Compressed Baryonic Matter (CBM) experiment is one of the experimental pillars at the FAIR facility. CBM focuses on the search for signals of the phase transition between hadronic and quark-gluon matter, the QCD critical endpoint, new forms of strange-matter, in-medium modifications of hadrons, and the onset of chiral symmetry restoration.
The Silicon Tracking System (STS) is the central detector for tracking and momentum measurement.
It is designed to measure Au+Au collisions at interaction rates up to 10 MHz.
It comprises approximately 900 double-sided silicon strip sensors with 1024 strips per side, arranged in 8 tracking stations. It results in 1.8 million channels, having the most demanding requirements in terms of bandwidth and density of all CBM detectors. In the context of FAIR phase 0, the mini-CBM project is a small-scale precursor of the full CBM detector, consisting of sub-units of all major CBM systems,
which aims to verify CBM's concepts of free-streaming readout electronics, data transport, and online reconstruction. In the 2021 beam campaign at SIS18 (GSI), O+Ni collisions at 2 AGeV were measured with a beam intensity of up to $10^{10}$ ions per spill.
The first results are presented with a focus on the performance of the mini-STS (mSTS).