On The Possibility Of Using A Solid State Nuclear Reactor

摘要

The development of accelerator-based propulsion on a spaceship requires the presence of two accelerators to avoid electrical charging. The advantages of accelerators in propulsion usage are obvious; the exhaust ions have the speed of light, and a relative mass increases of 1000 or more, which brings high mass usage. An efficient solid state - no turbines and intermediary thermal stage on energy conversion - reactor system that transforms directly the fission energy into electric power is also required. The development of such reactor structures is based on deep understanding of fission, and the materials behavior in fission dominated structures. During the fission process the Uranium nucleus is splitting in two other lower mass nuclei having a total kinetic energy of about 3.2 10-11 J/fission (200 MeV/fission). The range of these fission products is depending on the penetrated material stopping power, and is due to ionization, phonon excitation and nuclear collisions. These three processes are driving to nuclear fuel heating, removed through thermal conductivity into the coolant agent. The electronic component dominates the fission products stopping. The energy loss process is producing by ionization of the lattice atoms important electron nano-showers loops heating the fuel. The ionization depends on the atomic charge number, material density and ion energy and ionization level. Following various Monte-Carlo simulations we observed that a planar condenser in nanometer range thickness, MomO (Metal-oxide-metal-Oxide) structure can become polarized if the metals differ by the electron densities. The nanometer dimension of the layers is driving to predominant quantum effects which, if mitigated may drive to electron hole multiplication due to excitonic effects and finally increasing the conversion efficiency. By extracting electric current from the fuel this needs less cooling power, and an optimal operating temperature can be maintained by controlling the heat flow. That makes the alternative of supra-conductive cryogenic nuclear reactor battery with power levels in Gw range to be something which worth to be considered. The paper describes various material combinations in order to achieve such direct fission based electric pile and its potential use for powering a e-ion accelerator structure for space propulsion to relativistic speeds.