Parametric Study of Beta-Endpoint Energy in Direct Energy Converters

Abstract : Several solid-state materials have been identified for potential use as direct-energy-converter (DEC) for isotope-based batteries. Numerical simulations, using a nuclear scattering code (MCNPX), have been performed to determine the electron energy deposited in the material. Two different parametric studies were performed 1) varying Beta-endpoint energy of a spectrum illuminating layers of silicon-carbide (SiC), 2) the other varying the material layers while keeping the Beta-endpoint energy constant. The goal of the simulations is to identify the regions within the materials of maximum energy deposition so DEC devices can be fabricated for higher efficiency. The results show that 50 keV and 100 keV Beta-endpoint energies stand to have most impact to future Schottky devices, generating the largest number density of carriers, and highest energy deposition efficiency in the first 10 micrometers of SiC.