Abstract
Large magnetoconductivities are observed on high-mobility Si inversion layers in the temperature range of 4-1 K at very small magnetic fields. With the use of current localization theory the inelastic scattering rate has been extracted from the data as a function of both temperature and electron surface density. Inelastic lengths of about 8×105 cm at 1 K have been derived from the results. Band-structure effects are observed in the localization phenomena at very high electron surface densities.