Particle Arc Therapy

A method of optimizing delivery of a particle beam at a target is disclosed. The particle beam is delivered from an output device at a plurality of control points. In implementations, the method comprises delivering a substantially continuous particle beam about the plurality of control points, iteratively adjusting a delivery time of the substantially continuous particle beam about the plurality of control points, and processing to undertake at least one of (i) pre-defining energy layers based on one or both of the control points and a control point sampling frequency, or (ii) sorting the energy layers.