Abstract: A method and apparatus for monitoring a scanning beam of penetrating radiation, such as a scanning proton beam used to irradiate tissue. The position of the beam is tracked in real time by interposing a scintillator film between a source and an object of irradiation. An imaging detector, in optical communication with the scintillator, provides an output that is indicative of the position of the radiation and its variation with time. The accumulated dose over a scan may also be monitored.

Abstract: An imaging ionizing radiation detector with a high pixel resolution is described. The detector comprises a scintillating crystal and associated sensors which determine the energy and position of the scintillation with high spatial, temporal, and energy resolution. The position sensing is done with a photon counting and position sensitive detector. The detector can achieve sub-millimeter resolution and the position determination is performed at MHZ rates.

Abstract: Diffractive optical elements (DOEs) consisting of a sandwich of two materials are described with an interfacial surface whose relief height impresses the desired optical phase. The two materials have nearly matched indices of refraction, so the interfacial surface has a profile that varies by many wavelengths and is easily fabricated. The materials are chosen such that the refractive index difference and dispersion obey a matching condition that renders the optical path difference (OPD) across the element constant across a broad band of wavelengths. This achromatizes the DOE in that the diffraction efficiency is independent of wavelength. This achromatic property and the fabrication ease allowed by the nearly index matched (NIM) materials enables hybrid refractive-diffractive elements to be fabricated by molding processes for broadband applications.