Influence of the tritium β- decay on low-temperature thermonuclear burn-up in deuterium-tritium mixtures

Low-temperature (T less than or equal to 15 keV) thermonuclear burn-up in deuterium-tritium mixtures with various deuterium-tritium-helium-3 ratios is considered. The general dependence is studied for the critical burn-up parameter x(c),= rho r(c) upon the initial temperature T, density rho(0), and tritium molar concentration y for the [D]:y.[T]:(1 - y)[He-3] mixture. In particular, it is shown that, if the tritium concentration y decreases, then the critical burn-up parameter x(c)(T, rho(0), y) grows very quickly (at fixed T and rho(0)). This means that tritium beta(-) decay significantly complicates thermonuclear burn-up in deuterium-tritium mixtures.