OPTICAL BEAM PROFILER FOR HIGH CURRENT BEAMS

High-power accelerators are being studied for several proposals based on high-flux neutrons driven by protons. An ECR ion source delivers a 80mA H+ beam at 95keV for a high intensity proton injector prototype (IPHI) developed by a CEA-CNRS collaboration. The purposes of this proposal include developments of new diagnostics to characterise the H+ beam. Classical interceptive diagnostics cannot be used because of the high current densities. So, it was decided to develop a new type of beam profiler. It is based on the resonant absorption of a laser light by metastable atoms produced by collisions with protons in an injected noble gas (Ar, Kr). The method and preliminary results are described.