Electrostatic subtraction radiography

A simple on-line analog method for subtraction radiography using electrostatic imaging techniques is presented, Various electrostatic imaging methods have been proposed for radiography. The best known is xeroradiography which has gained widespread use in mammography[1] and is based on x-ray induced charge cancellation on a prepolarized photoconductive plate to form an electrostatic latent image of the object. Another technique referred to as Electron Radiography [2] or gas ionography [3] employs a gas in an electric field such that free charge carriers produced in the gas by the x-ray photons subsequently form the electrostatic latent image of the object.