Design, modeling and simulation work has been done to develop a system of producing radioisotopes by using D-3He fusion and the Inertial Electrostatic Confinement (IEC) fusion concept. This work provides a set of requirements for moving from the previous proof-of-concept experiments to medically relevant dosages of the radioisotopes used in Position Emission Tomography (PET). This study focuses primarily on the production of 11C from the 14N(p, ) 11C reaction, and could be extended to additional PET isotopes. A target was designed for gaseous parent materials; it consists of vacuum tight panels placed inside the vacuum vessel of an IEC device. The side facing the isotropic source of 14.7 MeV fusion protons is a thin metal foil (~0.5 mm of Ti). The foil acts to separate the vacuum environment of the IEC device from the pressured gaseous environment of the target. Parametric analysis of the foil thickness and 14N gas pressure was performed to optimize the efficiency of fusion protons in producing 11C. The MCNPX 2.5.0 simulations predicted that an optimized system could produce 390 nCi of 11C with the present laboratory scale IEC device at the University of Wisconsin, which has a D-3He fusion rate of 2 x 107 protons per sec (p/s).