Abstract: A method and apparatus for ion-valve radiography allowing a multiplicity of copies to be made responsive to a single radiographic exposure. Radiation, differentially-absorbed by passage through an object to be studied, enters an exposure chamber having a foraminate film or mesh structure surrounded by a high pressure gas or radio-conductive liquid of a type which converts the impingent radiation into electrostatic charge. The chamber is bounded by a pair of electrodes establishing electric fields therein to cause a charge image of the object to form upon an insulating layer contained upon the mesh structure. After exposure, the charge-image-bearing member is moved to a printing chamber and a charge image is deposited upon an insulative material sheet by ion flow techniques, for subsequent development by xerographic techniques.