A NON-INTERCEPTING BEAM EMITTANCE MEASUREMENT DEVICE BASED ON NEUTRAL BEAM FLUORESCENCE METHOD AT PKU

A new concept to attain ion beam emittance through measuring the forward neutral beam without intercepting the beam transportion was proposed at PKU. The forward neutral beam produced by space charge compensation and seperated from the transporting ion beam with the help of a deflecting magnetic field, carries the entire emittance information of the original particle beam and becomes a fast and non-interceptive beam diagnostic tool. This idea was tested on PKU ion source test bench and the experimental results show that the neutral beam fluorescence method is feasible. Based on these qualification results, a formal non-intercepting emittance measurement device was designed. It is a 90 degree fullscale dipole analysis magnet combined with the classical pepper-pot technique. Testing and commissioning of the device have been performed on the PKU test bench. Details of design and comnissioning results will be presented in this paper.