Improving the reliability of IPM

Ionization profile monitors (IPMs) measure, in a non-destructive way, the profile of ion beams independently on whether the beam is bunched or not. Our application is the heavy ion synchrotron SIS, which can accelerate ions with a large variety of different masses and charges. The IPM is used to obtain information about the beam matching, the electron cooling and to support for any kind of machine experiments. To ensure reliable function and to increase the data accuracy we executed some important mechanical improvements. The resistive E-field plates were replaced by discrete electrodes. We designed a new (Multi-Channel-Plate) MCP-Phosphor-screen assembly of rectangular shape and large active area and in addition a module with a filament mounted in meander shape to monitor the degradation of the MCPs. The whole device was planned by respecting high field uniformity and small mechanical dimensions at a large clearance for the beam. (authors)