Exit window for electron beam in isotope production

An exit window for an electron beam from a linear electron accelerator for use in producing radioisotopes comprising:

• a cylindrical channel operatively connectable at one end to a vacuum Chamber configured for travel of the electron beam, Which has a Gaussian profile and peak flux approximately centered on a centerline of the electron beam;
• and
• a domed dished head at the other end of the channel, the domed dished head comprising a convex portion comprising two or more distinct convex radii and a concave portion comprising two or more distinct concave radii that differ from the two or more convex radii, wherein the two or more convex radii and the two or more concave radii provide for a gradual thickening of the window from a centerline of the exit window to the channel, allowing the domed dished head to resist pressure stress created by cooling medium circulating around a protruding crown of the domed dished head and the vacuum in the cylindrical channel and to maintain a combination of thermal stress and the pressure stress below the fatigue limit of the material forming the exit window.