GB1179277A - An Electron Discharge Device. - Google Patents

Abstract

1,179,277. Electron beam apparatus. FORD MOTOR CO. 14 Feb., 1967, No. 7026/67. Heading H1D. An electron window closing a substantially rectangular, elongated aperture in the wall of a discharge tube forming an electron irradiation device is provided, on the side facing the incident electrons, with a window support and heat sink of a thermal conductivity not below that of aluminium and having a peripheral support defining an elongated rectangular aperture and a plurality of non-intersecting, window-contacting, metallic supports supported by the heat sink and extending parallel to one another, at a uniform spacing of less than one inch, across the aperture, whereby to facilitate the dissipation of heat generated in the window by the incident electrons. The window material is clamped between a peripheral frame (Fig. 4, not shown) on one side and the support plate, Fig. 3, in which the bolt holes 29 mate with corresponding holes in the peripheral frame, and the metal support members 25 are held within end slots 27. Coolant is circulated through a tube 33 mounted in a peripheral channel 31 of the plate. In an alternative embodiment (Fig. 5, not shown), the support members extend longitudinally across the window aperture, and are combined with a plurality of separate, spaced, transversely extending coolant tubes. The window may be a thin sheet of aluminium, lithium, titanium, beryllium, or stainless steel, or of aluminium/ copper, aluminium/beryllium, or magnesium/ thorium alloy, and the window supporting assembly may be of copper, silver, or aluminium. The apparatus, which may be employed for the polymerization of radiation-curable coating compositions, may use either a magnetically scanned beam, or a sheet beam produced by a plurality of tungsten wires stretched between a pair of bus-bars (Fig. 7, not shown). Numerical data concerning dimensions, spacings, areas, window thickness, and permissible beam intensity are given; the window support assembly intercepts not more than 25% of the incident electrons, and a minimum value of 2% is referred to.