Dusty Plasma Fission Fragment Propulsion

The objective of this project is to experimentally characterize the electrostatic properties of micron sized radioactive dust as it decays and fissions. The purpose of obtaining this information is to fill a gap in knowledge that is critical for the characterization and development of a dusty-plasma fission-fragment rocket engine (FFRE). This CIF proposal will provide the knowledge required to enable design of the confinement of a dust nuclear core using electric and magnetic fields. Human exploration beyond the moon requires an in-space propulsion technology we do not currently have. For the rapid transport of large payloads and humans, electric engines (e.g. ion and VASIMR) lack sufficient thrust and rely on intrinsically inefficient conversion of heat to electricity for thrust. Chemical engines are incapable of the sustained thrust required for short transit times and efficiency that permits an adequate payload/fuel mass ratio. More exotic fusion and antimatter concepts are currently not practical and will require decades to develop. The fission-fragment rocket engine (FFRE) makes use of existent technologies such as nuclear reactors, dusty plasmas, and high field strength superconducting magnets. The FFRE combines these technologies into a dusty-plasma nuclear core that offers, in the near term, an in-space propulsion system providing efficiently produced high thrust at unparalleled high specific impulse for months, enabling safe and practical human space exploration. The game-changing FFRE technology holds the potential to greatly reduce transit times, such as for Mars to a few months, minimizing radiation exposure and the health risks of prolonged weightless conditions. A fissionable dust nuclear core must be maintained through the use of electric and magnetic fields. This can only be done if the electric charge on the dust can be predicted as it decays, through the emission of electrons and alpha particles, and as it undergoes fission. The expectation is that the dust will charge negatively as fission products dominate a dust grain's electric potential through removal of positive charge. It is also expected that the work function for secondary electron emission will go to zero at a negative electric potential that is most strongly dependent on dust grain size. If so the electric potential will stabilize at some negative value that can be predicted once the behavior is quantified through the proposed study. More »