Toward electron self-localization in H2 gas: Multiple scattering effects on the electron drift mobility at low temperature and intermediate densities

We report here the first measurements of the electron drift mobility μ in gaseous H2 in the intermediate density range 0.5 × 1026 m−3 ≤ N ≤ 5 × 1026 m−3, at low temperature, T = 49.7 K and T = 29.7 K. In this range, the density is small enough to make the presence of electron states self-localized in bubbles negligible but, at the same time, is large enough for multiple scattering effects to alter the prediction of the classical kinetic theory for the mobility of quasi-free electrons. The analysis of the present data confirms the validity of the model we have developed to describe the quasi-free electron mobility in dense noble gases, which is based on the heuristic inclusion of multiple scattering effects in the classical kinetic theory.