Upper critical field of a superconductor near Anderson transition

We analyze the temperature dependence of the upper critical field of a superconductor which is close to Anderson metal-insulator transition, taking into account the magnetic field on the generalized diffusion coefficient. Some important deviation from usual behavior of ''dirty'' superconductors and the complete picture of Hc2(T) for different degrees of disorder up to localization region are obtained. Magnetic field effects upon diffusion are especially important for Hc2 behavior of a superconductor within the localization region. (orig.)