Discharge start-up in a tokamak with a poloidal divertor

The paper considers the problem of organizing a regime with an expanding magnetic limiter in a tokamak with a poloidal divertor in order to suppress skin effects in the current rise stage. Various laws of limiter expansion may be applied by regulating the current in the divertor conductor. The paper also considers some questions relating to the ionization of the working gas (hydrogen) in a tokamak: the role of processes involving molecules, and controlled influx of the gas. The analysis is performed by means of numerical calculations of a zero-dimensional and one-dimensional model of the initial stage of the discharge. (author)