In the phase I project all tasks of the work plan have been completed. Stress analyses have been performed for three separate window geometries yielding overall stress distribution at the 10 Megawatt power level. The thin cylindrical shell having a characteristic impedance of 10 ohms with wave matching sections on either side demonstrated the lowest stress levels at full power. The maximum tensile stress in this geometry using TPA window material is 0.1E*8 Pa. Multipacting analysis was completed and no significant multipacting appeared at any power level up to 10 Mega Watts using a pessimistic SEY of 2.5 for the ceramic coating. A comparison of candidate materials with regard to all relevant electrical and thermal mechanical properties identified Translucent Polycrystalline Alumina (TPA) as a preferred choice. A complete set of engineering drawings along with a production plan was produced for the window assembly.