Production and suppression of 11Cin the solar neutrino experiment Borexino

Cosmogenic 11 C is produced in‐situ by atmospheric muons and forms the main background for the measurement of solar pep‐ and CNO‐neutrinos. However, FLUKA simulations show that the majority of 11 C is accompanied by a free neutron in the final state, thus allowing for an efficient tagging method, the so‐called Three‐Fold Coincidence technique. The technique and its first applications on Borexino data are presented.