GB880124A - Thermonuclear reactor and method of initiating and sustaining a thermonuclear reaction - Google Patents

Abstract

880,124. Nuclear fusion reactors. UNITED STATES ATOMIC ENERGY COMMISSION. June 12, 1959 [Aug. 7, 1958], No. 20163/59. Class 39 (4). A method of initiating and sustaining a thermonuclear reaction in an evacuated chamber comprises establishing a first value of containing magnetic field in a part of the chamber to form a magnetically contained sub-volume, the containing field comprising two magnetic minor regions spaced apart axially and having a minor ratio of at least 3À5 to 1; initiating a hot plasma within the part of the chamber; increasing the magnetic field strength to a second normal operating value after the plasma is formed and simultaneously feeding fuel into the plasma at a rate sufficient to sustain the plasma and to gradually fill the sub-volume with plasma ; and then continuing the fuel feed while at the same time continuously altering the configuration of the field to gradually increase the distance between the minor regions until the desired operating distance is reached, thereby filling the entire containing magnetic volume with plasma. In Fig. 1 a cylindrical evacuated vessel contains a pair of end plates 14, 15 and a breeding blanket I is surrounded by magnetic minor coils 2, 3 and by coils 17 which are energised initially to produce a minor field near that of coil 2. High energy molecular ions from source 4 are shot into the reaction space and dissociated into atomic ions by an arc struck between cathode 8 and anode 9; this produces a hot plasma in the space between the minor coil 2 and the temporary minor formed by coils 17, an das soon as the plasma is formed the magnetic fields are increased by a factor of 5, the arc is shut off, the injection of molecular ions is discontinued, and cold fuel is injected into the plasma from source 11. The temporary minor produced by soils 17 is then moved gradually to the right until the plasma fills the entire working volume of the apparatus. The breeding blanket 1 may be of lithium to produce tritium and may contain beryllium which produces extra neutrons by (n, 2n) reactions. The blanket and the end plates may be cooled by water which may circulate through an external heat exchanger to produce power. In another arrangement, Fig. 2 (not shown), the reaction vessel is toroidal. Specifications 853,916 and 869,344 are referred to.