System and method for multiple particle therapy

A system for delivering two types of particles to a target within the body of a patient. A proton beam therapy system produces a beam of protons that is directed from a nozzle towards a target isocenter located within the body of a patient. The beam of protons can pass directly to the patient or pass through a neutron source comprised of a plate of neutron-rich material. Collisions between some of the protons and neutrons cause neutrons to be emitted from the material thereby generating a multiple particle beam comprised of both protons and neutrons. Preferably, the neutrons comprise only a small percent of the total particles in the beam. In the preferred embodiment, the neutron source is comprised of a plate of Beryllium that is interposed between the nozzle and the patient.