Control of a hysteretic electromagnetic electron lens system

The design of electron lenses for high-precision applications is complicated by ferromagnetic properties such as limited transition time and hysteresis. To be able to achieve high focusing precision and fast transition times, these properties should be taken into account when designing suitable controllers. In this project, feedback control, feed-forward control and feedback/feed-forward control topologies have been evaluated and trajectory planning has been implemented to reduce overshooting. Feed-forward control in particular proved to be a low-cost solution while the achievable transition time reduction is significant using the proposed automated tuning procedure.