Patent Number: 
Section: claims

1. An apparatus for determining residual energy of positively charged particles after passing through a patient, comprising:a multi-layer detector, comprising;a first layer comprising a first scintillation material, said first scintillation material, responsive to passage of the positively charged particles, emitting first secondary photons over a first wavelength range;a second layer comprising a second scintillation material, said second scintillation material, responsive to passage of the positively charged particles, emitting second secondary photons over a second wavelength range, the first scintillation material differing from the second scintillation material;a third layer comprising a third scintillation material, said third scintillation material, responsive to passage of the positively charged particles, emitting third secondary photons over a third wavelength range, said third scintillation material differing from both said first scintillation material and said second scintillation material; andorientation of said first layer, said second layer, and said third layer within thirty degrees of orthogonal to a path of the positively charge particles, said second layer positioned between said first layer and said third layer, a front surface of said second layer within ten centimeters of said first layer, a back surface of said second layer within ten centimeters of said third layer. 2. The apparatus of claim 1, said multi-layer detector further comprising:a first sub-stack of scintillation materials comprising said first layer, said second layer, and said third layer; anda second sub-stack comprising a manufactured copy of said first sub-stack. 3. The apparatus of claim 2, said multi-layer detector further comprising:at least ten layers of scintillation materials, said at least ten layers of scintillation materials comprising:said first sub-stack; andsaid second sub-stack. 4. The apparatus of claim 1, further comprising:an imaging system configured to use output from said multi-layer detector to generate an image of a tumor of the patient. 5. A multi-layer detector, comprising:a first layer comprising a first scintillation material, said first scintillation material, responsive to passage of the positively charged particles, emitting first secondary photons over a first wavelength range; anda second layer comprising a second scintillation material, said second scintillation material, responsive to passage of the positively charged particles, emitting second secondary photons over a second wavelength range, the first scintillation material differing from the second scintillation material,wherein said first scintillation material further comprises a first responsivity to the positively charged particles at least twice as responsive, in terms of number of emitted photons per unit energy released from the positively charged particles, as said second scintillation material. 6. The apparatus of claim 5, further comprising:an accelerator configured to generated the positively charged particles;a beam transport system configured to transport the positively charged particles from said accelerator, over a patient positioning system, and into said multi-layer detector. 7. The apparatus of claim 5, further comprising:an imaging system configured to use output from said multi-layer detector to generate an image of the patient. 8. A method for determining residual energy of positively charged particles after passing through a patient, comprising the steps of:passing the positively charged particles into a multi-layer detector element;detecting first secondary photons, resultant from passage of the positively charged particles, over a first wavelength range from a first layer of said multi-layer detector, said first layer comprising a first scintillation material; anddetecting second secondary photons, resultant from passage of the positively charged particles, over a second wavelength range from a second layer of said multi-layer detector element, the first wavelength range differing from the second wavelength range; andgenerating a set of response signals, each of at least six individual members of said set of response signals relating to a corresponding layer of a set of at least six layers of said multi-layer detection element. 9. The method of claim 8, further comprising the step of:detecting third secondary photons, resultant from passage of the positively charged particles, over a third wavelength range from a third layer of said multi-layer detector element, a third mean wavelength of the third wavelength range differing from both a first mean wavelength of the first wavelength range and a second mean wavelength of the second wavelength range by at least ten nanometers. 10. The method of claim 8, further comprising the step of:generating said set of response signals using two or three distinct scintillation material types.