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Theoretical and experimental investigations of the concentration dependence of mobility were carried out at T = 300 and 77 °K in the concentration range from 1012 up to 5 × 1017 cm−3. For non‐oxidized, highly pure crystals of n‐Si the experimental data are in good accordance with the theory, taking into account the lattice and impurity as well as intervalley scattering. The presence of high oxygen concentration in silicon samples results in a considerable decrease of the absolute mobility values fundamentally at diminished temperatures and small impurity concentrations. The observed decrease of mobility can not be explained by neutral impurity scattering of current carriers.

By solving the kinetic Boltzmann equation, a quasi‐momentum distribution function for charge carriers in p‐Ge is found taking into account the non‐sphericity of the constant energy surfaces of light and heavy hole bands. Account is also taken of the anisotropic carrier scattering by ionized impurities and acoustic lattice vibrations. The magnetic field and temperature dependences of the Hall‐factor rH are calculated for fields 0 < B ≦ 5 T and temperatures 77 K ≦ T ≦ = 260 K. The results calculated are compared with measured τH values obtained on oriented p‐Ge samples with free carrier concentration p ≈ 1.7 × 1014cm−3.

An analytic expression is derived which determines the electric field strength E(r) in the sensitive region of an one‐open‐face coaxial detector (spheric coaxial detector ‐ SC detector). The cases of no charge in the sensitive region (Na‐Nd = 0) and of uniform charge distribution (Na‐Nd = = const. ± 0) are considered. The applicability of the expression obtained is confirmed experi‐mentally for a model SC detector. The E(r) dependence in SC detectors is shown to be steeper than in coaxial detectors with two open faces (right coaxial detector ‐ RC detector). This de‐pendence is found to steepen when approaching the closed face and near it and to be steepest along the cylinder axis.