VIMOS, near-target beam diagnostics for MEGAPIE

A correct intensity distribution in the incident beam is of highest importance for the Megawatt Pilot Experiment (MEGAPIE) liquid–metal spallation target at PSI. VIMOS is a new optical system which monitors the glowing of a tungsten mesh heated by the proton beam by means of a fast radiation-resistant camera. The experience gained with the system during 3 years is very positive, further improvement in terms of easy maintenance is still planned.