Abstract
A beam flattening technique for heavy charged particle radiotherapy has studied using a double scatterer method. In order to calculate flux distributions for the double scatterer system, we have introduced three parameters on the geometrical scaling factors of the system. The flux distributions at the therapeutic site were calculated on the various combinations of the scatterers and the beam stopper using the parameters. From these results, it is possible to deduce an optimum solution of the uniform dose distribution and the efficient beam delivery for any heavy charged particle radiotherapy facilities. As typical examples, we have tried to apply this method to NIRS proton radiotherapy facility and to PARMS proton radiotherapy facility of the University of Tsukuba.
