Generation of tritiated methane using a CuO-Al4C3 bed

With the supply of a constant flow rate of hydrogen with a constant tritium concentration to a CuO-Al4C3 bed at 573 K, methane with a constant radioactivity was generated at a high conversion ratio. Although tritiated methane was conventionally generated using a set of tritiated water vapor bubbler and an Al4C3 bed, its tritium radioactivity was limited by the saturated water vapor pressure and was dropped by a large decrease in density when water was vaporized. The present CuO-Al4C3 bed can substantially eliminate its limit because of the successive conversion from hydrogen to methane using a CuO-Al4C3 bed heated to 573 K. The difference in output between the ionization chamber and the gas chromatography was discussed based on the complete-mixing series-tank model. (author)