The mechanical design of the BARREL section of the detector CALIFA for R³B-FAIR

The detector CALIFA (Calorimeter for the in flight detection of gamma-rays and light charged particles) is one of the key detectors of the R³B experiment at the FAIR facility. In this work we present the mechanical concept proposed for one of the sections of the detector CALIFA: the BARREL section. The BARREL section consists in the active core of the CsI(Tl) crystals and the mechanical structure to hold and move the active core. The use of an alveolar structure made of carbon-fiber composites allows for a light and robust solution to hold the active elements with an extreme mass ratio below 0.7%. The active core is supported by structural elements designed to make a fully operational assembly, taking care of different configurations and functionality