  The atomic hydrogen formation channels of the C + C2H2 reaction have been
investigated using a continuous supersonic flow reactor over the 52 K 296 K
temperature range. H-atoms were detected directly at 121.567 nm by vacuum
ultraviolet laser induced fluorescence. Absolute H-atom yields were determined
by comparison with the H-atom signal generated by the C + C2H4 reaction. The
product yields agree with earlier crossed beam experiments employing universal
detection methods. Incorporating these branching ratios in a gas-grain model of
dense interstellar clouds increases the cC3H abundance. This reaction is a
minor source of C3 containing molecules in the present simulations.
