Space Charge Studies for the Ionisation Profile Monitors for the ESS Cold Linac
Résumé
In this paper, we present the results from a numerical code developed to study the effect of space charge on the performance of Ionisation Profile Monitors. The code has been developed from the analytical expression of the electromagnetic field generated by a 3D bunch of charged particles moving along one axis. This transient field is evaluated to calculate the momentum gained by a test moving particle, but not necessary co-moving with the bunch, and included in a non-linear ordinary differential equation solver (Runge-Kutta) to track the 3D motion of the test particle. The model of the IPM is complete when an additional constant electric field is included to project the test particle onto a screen. The results from this code, modelling the IPM to be developed for the ESS Cold Linac, are presented here, and the impact of the space charge on the measurement of the beam profile is discussed.