Temperature dependence of the product branching fractions for the D₃⁺ + NH₃ reaction measured between 110 and 270 K. The data show the probability of formation of NH₃D⁺ (circles), m/z 20 (squares), m/z 21 (diamonds), m/z 22 (pentagons), and m/z 30 (hexagons, N₂D⁺ from background N₂). The dominant channel remains NH₃D⁺ formation across the entire temperature range; see the text for an interpretation of the minor reaction channels. Open symbols indicate measurements at T < 110 K that are influenced by NH₃ freeze out, as evidenced by the increasing signal at m/z 30 (N₂D⁺) from reactions with residual N₂.