ABSTRACT
The dimensions of a clinical target are typically different than the dimensions of an unmodified particle beam. The beam extracted and transported from a typical accelerator will have dimensions on the order of millimeters and will have a narrow energy spectrum, which results in a narrow spread of ranges in a target. Beam scanning can be defined as the act of moving a charged particle beam of particular properties and perhaps changing one or more of the properties of that beam for the purpose of spreading the dose deposited by a beam throughout the target volume. The beam parameters can, and should, be able to change on a location-by-location basis, for example two locations can have different ranges or beam sizes. Beam scanning is the process of spreading the beam over the target volume by moving the beam throughout the target. The earlier description appears intrinsically discrete or digital.
