For about 15-20 past years the experimental procedure and techniques in tokamaks have made great progress that enabled the plasma parameters to be effectively enough controlled and in some cases a number of dangerous instabilities to be suppressed; besides the plasma confinement was improved. However, the experimental rector, ITER, being designed with due account of the progress made is oversized and considered as an unduly expensive facility. Hence there naturally, arise a question: if the chosen way to develop tokamaks, i.e. permanent increase of their sizes (and cost), the only one correct? In fact, since major physical tokamak concepts were stated, main efforts have been undertaken in the development of the experimental procedures and techniques and “the arm race”, i.e. a competition in building larger and larger facility .If let the “ideology” of the tokamak creation unchangeable, then the only correct way left is to increase its sizes. As follows from the Lawson criterion the ignition may be achieved by increasing either the plasma density (this the case of laser nuclear fusion) or the confinement time. As the plasma density in the tokamaks is limited to a value of the magnitude of the magnetic field, one needs to increase the time of confinement. In its turn, this time in the existing tokamaks (stellarators) is limited because of the fact that their plasma proves to be substantially non-equilibrium and suffers numerous instabilities. In the paper an alternative method to increase the plasma density has been suggested. In the magnetic nuclear fusion reactor (MNFR) discussed below the magnetic field of tokamak (or stellarator) type is mainly used for thermal isolation of the hot plasma, while its pressure is confined by high pressure gas (for instance, deuterium-tritium mixture). This work deals with the main physical aspects of the reactor: plasma equilibrium, instability, self-sustaining fusion burning and the possibilities of the non-inductive current drive due to the bootstrap mechanism. The bootstrap current generated in the fusion plasma is shown to be quite sufficient to maintain a poloidal magnetic field required for thermal isolation of the hot plasma. A series of obvious advantages of using high-pressure gas for the confinement of plasma pressure and energy are noted, e.g. absence of interaction fast charged particles and first-wall components, small sizes of the reactor and opportunity for using other fuel mixtures (f.e. D+He³).
Keywords: high-pressure gas, confinement, fusion burning, reactor, bootstrap current