Apparatus and methods for electron beam irradiation

An electron beam accelerator has an accelerator tube consisting essentially of metal and ceramic components which are fused directly to each other and a transmission window generally rectangular in shape when viewed in the direction of the electron beam and is convex towards the vacuum chamber with a radius of curvature which is at most twice the width of the rectangle when measured in the absence of a pressure differential across the window. The electron beam accelerator is particularly suitable for use as a liquid material processor. The preferred transmission window of the accelerator of the invention can withstand energy transfer rates of at least 1500 watts per gram of the window material to which the energy is transferred. Certain embodiments are especially suitable for irradiating fluids to higher doses or for irradiating liquids containing suspended solids or slurries. A mobile transporter enabling relocation of the liquid material processor between process sites is also described.