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Ionography, which is currently receiving much attention, is an x-ray image recording system in which the detector is a thin ionization chamber usually containing a heavy, high pressure (10 atmospheres), gas. Ions formed by x-rays in the gas are swept across the chamber by an electric field onto a thin insulating film to form a charge image. In current systems the chamber is then depressurized, the film removed, and its charge image made visible using powder or liquid toner. An alternative method is herein described for making the charge images visible which overcomes the mechanical problems of film and gas handling of present techniques. An added advantage is that it produces instantaneous bright, stored, projected images which offers the potential of fluoroscopic ionography. In the new technique charges are collected onto a thin clear deformable layer of oil or soft elastomer coating a front surface mirror in the chamber. Electrostatic forces between the surface charges and the conducting mirror cause imagewise deformations which are immediately made visible on a external screen by a Schlieren Optical Projection System using light which enters and leaves the chamber through a high pressure glass window. Images, with resolution better and sensitivity close to film/screen methods, have been obtained.
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