The FCAL collaboration is preparing large-scale prototypes of special calorimeters to be used in the very forward region at future electron positron colliders. The forward region sets challenging requirements on several detector parameters, such as detector compactness, radiation hardness, or readout ASICs parameters. Prototype detector planes assembled with dedicated FE and ADC ASICs for LumiCal and BeamCal have been built. We present R&D activities focused on the development of prototype detectors able to cope with these requirements.
The results of their performance following tests in an electron beam are reported. High statistics data were used to perform sensor alignment, and to measure the longitudinal and transversal shower development in the compact calorimeter prototype. Besides, Geant4 MC simulations were done and compared to the data.