Four-dimensional phase space measurement using multiple two-dimensional profiles

Knowledge of 4D beam phase space is essential to characterize beam motion along a beamline which includes elements that couple the transverse planes. A 4D phase space measurement method using multiple 2D profiles is proposed in this paper. The effectiveness of the method is validated by numerical simulations. Finally, we present a successful application of the method at the Xi'an Proton Application Facility to measure the coupled 4D phase space after a skew quadrupole.