The start-up of tokamaks and the tokamak start-up

In this paper the author considers the case of a successful start-up, JET, and then two cases whose startups are still under discussion, INTOR and NET. The author discusses that during the initial phase of any toroidal confinement scheme, not only the pressure and temperature values increase but also their profiles change continuously. The author cites that several years ago he found that there exists a unique family of axisymmetric equilibria, which can be considered as tokamaks, for which one of three profiles - pressure, temperature and toroidal current profile - can be chosen in a largely arbitrary way without changing the distribution and in some cases even the absolute value of the external poloidal magnetic field necessary to ensure the equilibrium. The author concludes with an example related to the increase of the average kinetic pressure and of the average beta in such configurations