| 摘要 |
PURPOSE: To obtain an intensity gain by providing a luminous body layer where the energy from a first beam in a quasistable state and is released by electric excitation of a luminous flux, and controlling the depletion area of a scintillation plate. CONSTITUTION: A screen 2 includes a photosensitive material 20 between two plates 21 and 22 which have a property to absorb the energy given by a beam Fl, and electrodes 23 an 24 are provided on plates 21 and 22 and are connected to voltage sources 6 and 7. When an electric field is applied to the photosensitive material 20, the luminous body is excited, and an X-ray beam F1 in a form of a luminous flux F2 is received to release the stored energy. The efficiency of the screen (scintillation plate) at the time of picture recording is increased according as the width of a depletion area of the scintillation plate is increased. Therefore, the plate is uniformly illuminated by radiant rays of a light source 10, and a voltage pulse is applied to the whole of the plate during this illumination, and next, the whole of the plate is darkened and the voltage pulse is still applied. Thus, the x-ray photon/visible light photon conversion efficiency is considerably improved.
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