Nordic Winter Meeting on Physics @ FAIR

In-beam tests of the Lund R3B calorimeter prototype have been carried out at The Svedberg Laboratory, Uppsala, Sweden using the 179 MeV proton beam. The detector consists of a cluster of 5x3 CsI(Tl) crystals representing a section of the barrel of the calorimeter. An energy resolution of ~0.5% has been achieved and gain corrected summing has been tested. Results from the test, including multiplicity and sum spectra that show good agreement with GEANT4 simulations, will be presented.