Dynamical behaviour and spectroscopic studies on inorganic scintillators for high current ion beam operation

Scintillation screens are widely used for qualitative transverse beam profile monitoring in accelerator facilities. However, precise measurements might yield ambivalent results, especially for high beam current operation. At GSI, Helmholtz Centre for Heavy Ion Research, the optical properties of different inorganic scintillating screens under irradiation with ion beams are studied. Various ion beams in the energy range from 4.8 to 11.4 MeV/u are applied with currents up to some mA. Investigations are not only focused on the well-known sensitive scintillators but also on ceramics offering a higher radiation tolerance. For the data evaluation the image of each ion beam pulse was recorded and individually analysed. The obtained results as light yield, beam width and higher statistical moments are discussed. The light yield and the beam width show a dependence on the used scintillator material and change significantly with the screen temperature, which increases during beam impact. As a comparison to the obtained screen profiles, scraper based method was used. Furthermore the optical spectra in the range of 350-750 nm of the scintillating screens were recorded with an imaging spectrograph. For some materials the spectra of scintillating light differs significantly for light and heavy ion impact.