An Apparatus for the Production of Very Soft X Rays at High Intensity

An apparatus has been developed for producing high intensity x-ray beams at constant potential between 1 and 6 kV. An electron beam produced by a specially designed electron gun of the Pierce-Müller type bombards a rotatable target. Beam currents up to 500 mA have been achieved. The design permits the positioning of each of four different target materials into the electron beam. Targets are prepared by vacuum evaporation of the desired material onto a target block. A thin window (beryllium foil and Mylar film) provides an exit path for the x rays and has acceptable transmission at energies above 1.5 keV. Such very soft x rays are strongly absorbed in air, but may be brought through a helium path and plastic foil exit window to a test system for investigation of their effects.