CBM progress report 2020

The CBM experiment is designed for the exploration of the QCD phase diagram in the region of high baryon densities with high precision due to an unprecedented rate capability of the experiment. In the year 2020, significant progress towards the realization of this goal was made. In 2020 the FAIR project implemented the so-called intermediate objective (IO) targeted for project completion until 2027. As part of the IO the shell construction of the CBM building is making rapid progress with a projected completion date in 2021 allowing for an earlier installation of the CBM detector. In the framework of the IO also other subsystems like especially the SIS100 synchrotron could be brought to initial operation earlier than 2027. In order to be ready for using the first beams delivered by SIS100 the preparations of the CBM experiment follow the time line shown in Fig. 1. According to the planning the cave infrastructure like the rail system for the downstream detectors has to be installed already in 2022. The proposal to finance necessary common infrastructural items by common funds was accepted by the funding agencies as part of the CBM construction MoU after the cost had been scrutinized by the ECE and ECSG committees in several meetings. Concerning funds CBM is thus well prepared to execute the demanding timeline aiming at constructing and setting up the so called day-1 version of CBM until 2025. This version of the full setup was described in detail already in the Progress Report 2019 [1]. The collaboration is focussing now on preparing for series production of the detector elements. A prerequisite is the verification and qualification of pre-series components under realistic close to final operating conditions. Despite the difficult working conditions imposed by the pandemic these activities are pursued in dedicated test beams and in the ongoing CBM FAIR Phase-0 experiments: operation of mCBM, participation in the HADES experiment with the RICH photo detectors, participation in STAR with hardware (eTOF) and software (KFParticle), participation in BM@N with PSD and STS modules.