Electron motion in high-pressure polar gases: NH3

This is the authors' abstract. We don't add key points for this paper.

Drift velocities w for slow electrons in NH3 vapor have been measured and are reported as a function of the density-reduced electric field E/N (⩽24×10−17 V cm2), density N (2.43–292×1018 molecule cm−3), and temperature T (300–650 K). The w decreases with increasing N considerably and this decrease varies with T; for a fixed N it is higher the lower the T. Use is made of the T- and N-dependence of w to assess the role of the various processes which delay the electron drift. The density range above ∼2.5×1019 molecules cm−3 seems to represent the transition from the free (or quasifree) to the localized (anionic) electron state. The number density NL at which complete electron localization occurs, has been estimated at various T. At T=300 K, NL≃3.3×1020 molecule cm−3 or ∼0.01 g cm3. Estimates have also been made of the binding energy of the electron to the trapping species (possibly NH3 clusters) which, depending on T, range from 0.11 to 0.15 eV.