Fluid and thermal modeling for a liquid-cooled high-fluence electron-beam transmission window

Summary form only given, as follows. Energy loss from high-energy electrons that pass through a transmission window causes an increase in window temperature. A technique to cool transmission windows that utilizes water under high pressure flowing in capillary ducts is presented. A model for fluid flow in ducts quantifies fluid pressure, water temperature, convective rate, and vapor pressure as a function of distance into a capillary duct subject to uniform heating. The results quantify a design to prevent vapor formation in a capillary duct and provide a limit a 5-cm-diameter window that would support 30 mA/cm/sup 2/ continuously at a beam energy or 500 keV.