Theoretical study of the T+D2 and D+T2 collisions in low-temperature hydrogen plasmas

Abstract

The study of low-temperature hydrogen plasmas is relevant for many technological plasma applications. The theoretical investigation of elementary processes, especially those involving H, D, and T species, is crucial for the modeling of nonequilibrium plasma systems such as those found in fusion plasmas. We report fully quantum time-independent calculations of rate coefficients for the vibrationally inelastic and reactive collisions of T with ${\mathrm{D}}_{2}(v=0)$ and of D with ${\mathrm{T}}_{2}(v=0)$. Our calculations are based on the ${\mathrm{H}}_{3}$ global potential-energy surface of Mielke et al. [S. L. Mielke et al., J. Chem. Phys. 116, 4142 (2002)]. We obtain state-to-state rate coefficients for the formation of DT through $\mathrm{T}+{\mathrm{D}}_{2}$ and $\mathrm{D}+{\mathrm{T}}_{2}$ reactions and for the vibrational excitation of ${\mathrm{D}}_{2}$ by T and of ${\mathrm{T}}_{2}$ by D for temperatures up to 2500 K. The results are compared to existing ones for other hydrogen isotopes and significant differences are found between the different sets of results, confirming that specific data have to be obtained for all the collisional systems of interest of hydrogen plasmas. We expect that this data will allow a more accurate modeling of hydrogen plasmas of interest for technological applications.