Final design of a monitoring system and software correction cycle for the mirror alignment of the CBM RICH detector

The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will explore the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions. The energy spectrum will start at 2 AGeV/c and extend up to 11 AGeV/c for the heaviest nuclei at the SIS 100 accelerator set-up. To explore the physics program of CBM, a RICH detector will be employed for electron identification and pion suppression in a momentum range up to 8 GeV/c. Mirror alignment is a key issue for a proper detector operation. The final conceptual design for a monitoring system of the alignment of the mirrors of the CBM RICH detector will be introduced. It consists of a fast qualitative check of the alignment as well as two different methods to derive quantitative numbers for misalignments. A software correction cycle had been developed which, once applied allows to get back to physics performances as in an ideally aligned case.