Calculation of Low-Energy Electron-Atom Transport Cross Sections from Total Cross-Section Measurements

Modified effective-range theory (MERT) is used to determine the cross sections necessary for calculation of electron-atom transport coefficients. Two means of obtaining the transport cross sections are given: (1) direct integration of the weighted MERT differential cross section, and (2) inserting MERT phase shifts in a partial-wave formula for the transport cross sections. Both of these approaches are applied to $e^{-}$-Ar collisions, and it is found that the second method is more useful for energies above ${10}^{-3\mathrm{}}$ eV. The constants given by Golden and Bandel are used to calculate the first four transport cross sections for $e^{-}$-Ar and $e^{-}$-He collisions for energies below 0.5 and 2 eV, respectively.