Progress with performance simulations of the CBM Silicon Tracking System

Efficient charged particle tracking and high momen- tum resolution are central performance requirements of the CBM Silicon Tracking System (STS). The aim of the on- going layout studies is to design a highly granular and low- mass detector system which can track up to 1000 charged particles that are typically generated in one central Au+Au collision at 25 GeV/u projectile energy. A low-mass de- tector is crucial to achieve a momentum resolution down to 1%. Progress has been made with optimizations of the detector geometry and with the implementation of realistic detector response functions.