Toward an environmental friendly operation of the CBM-TOF system

Abstract

The future fixed target high-rate compressed baryonic matter (CBM) experiment is one of the experimental pillars of the Facility for Antiproton and Ion Research (FAIR) located in Darmstadt/Germany. In order to provide an excellent particle identification (PID) of charged hadrons, the CBM-time-of-flight (TOF) group has developed a concept of a 120 m$$^2$$ 2 large TOF wall with a system time resolution below 80 ps based on multi-gap resistive plate chambers (MRPC). Currently, timing MRPC systems are operated with a gas mixture based on tetrafluoroethane (R134a, C$$_2$$ 2 H$$_2$$ 2 F$$_4$$ 4 ) with additions of few vol% quencher gases, e.g., sulfur hexafluoride (SF$$_6$$ 6 ) or/and isobutane (i-C$$_4$$ 4 H$$_10$$ 1 0 ). Unfortunately, these gas mixtures have a high global warming potential (GWP) in the order of 1500, and therefore, strategies to reduce the environmental impact have to be developed. The various possibilities, including studies on eco-friendly gases, and the considered strategy by the CBM-TOF group will be elaborated in this article.