System/ SubSystem Engineering Interface Considerations and R&D Requirements for IEF /QEDd Engine Systems

Extremely advanced space propulsion systems, based on use of inertialelectrostaticfusion IEF lightweight, high power fusion energy sources FES, use p 11B reac tions for radiationfree production of energetic charged particles. These can be converted directly to electrical power to heat propellant by injection of subrelativistic ebeams REB into propellant in magneticallyinsulated thrust BMT chamber. This paper presents an examina tion of engineering interfaces and limits important in each major subsystem of a complete IEF engine system. In the FES, the principal limit is high voltage stando and arcing; in the REB ebeam transport stability and limits on diode emission are of concern, while main BMT problems include ebeam injection, coupling to propellant plasma, and suppression of plasmato structure heat transfer. In the complete QED engine system the principal problem is maintenance of vehicle charge neutrality. Potential engineering solutions for each of these are defined and examined and their limits determined. An R&D program to address and resolve these and allied issues has been shown to require about 33.5B over 1417 years, to yield a fullscale prototype QED engine system, at 5000 MWe with Isp> 2500 sec at F 40,000 kgf 400 kN. The QED Engine Syste