Advancements in the Silicon Tracking System of the CBM experiment: module series production, testing, and operational insights

Abstract Designed to function as the primary tracking detector for the future CBM experiment at FAIR, the Silicon Tracking System (STS) is tailored to measure charged particles generated during heavy-ion collisions at very high interaction rates of up to 10 MHz, using a triggerless free-streaming readout approach. The detector modules developed for STS integrate large-area double-sided microstrip silicon sensors, lightweight high-density interconnecting microcables, and a custom-designed self-triggered readout ASIC. This configuration results in modules with a low material budget capable of providing 2D position information alongside timing and amplitude data. Central to the STS project is the reliable series production of detector modules and ladders, which also involves assembly and quality control measures for each component. A comprehensive functional and thermal stress testing of the fully assembled modules ensures their reliability before their integration onto carbon-fiber ladders. Beyond these production tests, the operational capabilities of STS modules are evaluated in various application scenarios. High-intensity nucleus-nucleus collisions at GSI facilities and the E16 experiment at J-PARC serve as test benches for evaluating their performance. This report provides an overview of the quality checks applied in the STS module production, results from functional module testing, and insights gained from their operational deployments across distinct experimental setups.