Gas Scintillation Beam Profile Monitor at Cosy Jülich *

The interaction of ion beams with the surrounding residual gas leads to photon emission by the excited residual gas atoms and molecules. These photons in the visible spectrum range can be used to monitor the transverse beam profile. We therefore use a multichannel photomultiplier (PMT) together with an optical imaging system. Measurements at COSY synchrotron of the Forschungszentrum Jülich are presented. The usability of the method is discussed by comparing to measurements at the iThemba LABS beamline and the beamline of the JESSICA experiment, a neutron spallation source test setup at COSY.