A scintillation based imaging system. The device utilizes a single-crystal inorganic scintillator to convert ionizing radiation to light in a spectral range or ranges within the visible or ultraviolet spectral ranges. The conversion takes place inside the single crystal material, preserving special resolution. The single crystal scintillator is sandwiched between a first plate that is substantially transparent to the ionization radiation and a second plate that is transparent to the visible or ultraviolet light. The ionization radiation is directed from the submicron source through a target to create a shadow image of the target inside the scintillator crystal. Several submicron sources of radiation are described. These include submicron x-ray and high-energy ultraviolet sources, submicron electron beam sources, submicron alpha particle sources, submicron proton sources, submicron positron sources and sub-micron neutron sources. Also, Applicants describe submicron spot size x-ray sources produced using electron beams alpha particles, protons and positrons. In preferred embodiments larger size sources are converted to submicron sources by focusing the radiation to a submicron neck, by blocking all but a submicron portion using a pinhole arrangement or by channeling the radiation with a pinhole funnel.