Energy Storage and Conversion in Solid Hydrogen

Abstract : The trapping of unpaired atoms of hydrogen (H) in a solid hydrogen matrix (Hsub2) increases the energy available for propulsion applications, i.e. the specific impulse. The incremental increase in stored energy depends on the metasable atomic hydrogen concentration. To maintain a large atomic hydrogen concentration, recombination of atoms into molecules must be understood and suppressed. It was the purpose of this research to study both theoretical and experimental approaches to creating large atomic hydrogen concentrations. The theoretical considerations have lead to analytic procedures for calculating the atom diffusion times and the atomic recombination coefficients from statistical mechanics. The experimental studies have yielded numerical estimates of the atom density in solid tritium based on measurements of the ortho to para tritium conversion rate. The atom density expressed as a concentration approaches 1% near K. Such large atom densities lead to very unusual thermal response when the temperature of the host solid matrix is increased, resulting from the rapid recombination of the trapped atoms. In practice, this response provides a method of retrieving the stored energy from the host solid