Patent ID: 6749903
Filing Date: 2004-06-15
Classification: H01J

Abstract:
A method of irradiating an article with an electron beam said article comprising a coating that can be modified by electron beam radiation on a substrate that can be degraded by electron beam radiation passing through the coating, said article being oriented so that the coating faces the electron beam, said method comprising:providing an electron beam source; providing a window for use with the electron beam source, the window comprising a polymeric film having at least two surfaces and a protective layer resistant to free radical degradation on at least one of the surfaces, said window having a unit path length of 3-54 g/m2; and irradiating the article through the window with electrons from the electron beam source, the electron beam source having an energy of between about 30 and 150 keV before passing through the window, and the intensity of the electron beam radiation being sufficient to modify the coating, wherein the parameters of the method, such as the gap between the window and the article, unit path length of the window, coating thickness, and electron beam source energy are set so that the intensity of electron beam radiation received by the surface of the coating facing the electron beam is between 1 and 5 times greater than the intensity of electron beam radiation received by the surface of the coating facing the substrate.