Installation manner null of the emission optical transmitted thin film in the emission optical transmitted window and the emission optical transmitted

摘要

PURPOSE:To enable an exposure treatment of a transfering device side under an atmospheric condition and also to enable grading up transmissivity of a radiation beam by forming a radiation beam transmitting thin film to be spherical, protruding to a side of a radiation beam source, and by lessening its thickness gradually towards its center. CONSTITUTION:A radiation beam transmitting thin film 1 is formed spherical protrudingly to a side of a radiation beam source. By this treatment, the thin film 1 is made to endure a tensile stress working to the thin film 1 derived from pressure difference between the radiation beam source side and the transfering device 4 side. By using the thin film 1 being shaped spherically in this way, tensile stress sigma shown in the figure, is solely works to the thin film 1. Accordingly, even if a film thickness t is small, the tensile stress sigma can be arbitrarily applied, by selecting a spherical curvature R corresponding to the film thickness t. Also, in order to make intensity of the radiation beam obtained at the device 4 side, to be of almost the same everywhere, the film thickness t is formed so as to get thinner towards a spherical center part C of the thin film 1, at its periphery, and therewith all transmitting distances of the radiation beams through the film are made to be quite same at every position.