A Pointing Electromagnetic Calorimeter for FIP Experiments leveraging X → γγ Decays Sebastian Ritter, Volker Büscher, Matei Climescu, Reinhold Degele, Claudia Caterina Delogu, Karl-Heinz Geib, Steffen Schönfelder and Rainer Wanke EPJ Web Conf., 320 (2025) 00011 Published online: 07 March 2025 DOI: 10.1051/epjconf/202532000011