Diffusion tube data related

Lindinger 1984). Rather, we are concerned with the question as to what extent, and under what astrophysical circumstances, may drift tube data be properly applied to elucidate interstellar chemistry, specifically diffuse and dense cloud chemistry and to the chemistry of the shocked regions of interstellar gas. Towards this end, we present some sample data relating to atomic ion reactions which are believed to be applicable to interstellar chemistry and also some other drift tube data relating to molecular ion reactions which illustrate the influence of internal excitation of the molecular ions on their reactivity. 

Katz and Scott used equation (7) to calculate diffusivity data from measurements made on a specially arranged open tube. The equation that explicitly relates dispersion in an open tube to diffusivity (the Golay function) is only valid under condition of perfect Newtonian flow. That is, there must be no radial flow induced in the tube to enhance diffusion and, thus, the tube must be perfectly straight. This necessity, from a practical point of view, limits the length of tube that can be employed. 

---