[en] A method is described for separating isotopes in which a selected isotope is first ionized in a partially bounded region and then driven toward the boundary by space charge electric fields. Radial electric fields, which accelerate movement of the charged particles towards the walls of the boundary, are generated by charge separation associated with ambipolar diffusion of the particles in the plasma column. Selective photoexcitation leads to the preferential ionization of the isotopic component to be separated from the gas mixture. The resulting altered gas mixture component concentrations in the central region and periphery of the bounded area flow from the system through different output channels