Toroidal reactor

#In the field of physics a need exists for high temperature plasmas of ions and electrons. Various means and appratus have been proposed and used for providing such plasmas comprising the toroidal research reactors at Princeton University referred to in the art as stellarators. Such torodial configurations are described and shown in U.S. Pat. Nos. 3,278,384 by Leonard et at., entitled "Negative Stellarator"; 3,016,341 by Spitzer, Jr., entitled "Reactor"; 3,002,912 by Spitzer, Jr., entitled "High Temperature Apparatus". In an effort to achieve a hot dense plasma, several techniques have been employed. Furth et al, in U.S. Pat. No. 3,702,163 discloses a device for heating and compressing a plasma colum. Another method for heating a plasma is disclosed in U.S. Pat. No. 3,713,967 to Hamilton et at. in which a neutral particle beam is injected into the containment zone of a reactor vessel in order to heat the plasma and in U.S. Pat. No. 3,755,073 to Haught et al. in which a neutral particle beam is injected into a target plasma to maintain a high plasma temperature due to thermal collision between the ionized beam particles and the plasma. While these and the other torodal plasma research reactors used heretofore have been successful research reactors, they have had to meet the criteria of the well-known Lawson's minimum condition on n.sub.1 96 .sub.E, which is the product of the ion density n.sub.i and the plasma energy confinement time .tau..sub.E, in order to generate sufficient thermal power to recreate the electrical power invested in producing the plasma. A theoreticla dicussion of this Lawson criteria is provided in Proc. Phys. Soc., B (London 70, 6(1957)).

#It is an object of this invention to operate a plasma reactor to provide a plasma of ions and electrons under conditions less restrictive than the above-metioned Lawson criteria.

#It is another object to provide a two-component plasma.

#In the drawings where like elements are referenced alike:

#FIG. 1 is a graphic illustration of the instantaneous reaction probability of a neutral beam that bombards a magnetically confined bulk plasma in which a 180-keV deuteron slows down in bulk tritium plasma of T.sub.e =5 keV, T.sub.i =0. Instantaneous probability of fusion and division of deuteron energy between electrons and tritons are also shown. (the 11/4 factors are calculated at n=3.times.10.sup.13 cm.sup.-3.)

#FIG. 2 is a graphic illustration of the results of FIG. 1 at a variety of energies and target electron temperatures. The figure represents the energy multiplication factor F as a function of deuteron injection energy W.sub.0 for various electron temperatures of cold-triton-target plasma, assuming total energy release of 22.4 Mev.

#This invention is useful in the field of plasma physics. To this end, this invention provides plasma particles that are confined in a strong toroidal magnetic field, e.g., from several KG up to 150 KG or more at densities of up to 10.sup.12 particles/cm.sup.3 or more. Suitable species of ions in the plasma comprise deuterons, He.sup.3 and tritons. The invention operates mainly with a two-component plasma. An energetic or high-temperature neutral deuterium beam is injected and retained in the lower-temperature bulk tritium plasma as an energetic ion component which interacts with the existing background plasma ions. This two-component plasma gives rise to more rapid fusion reactions than would be achieved when operating with a single-component plasma, where tritium and deuterium ions are at the same bulk plasma temperature.

#In understanding this invention, it is known that suitable plasma confinement means, such as the well-known stellarators described in the above-mentioned publications, can magnetically confine high temperature one-component plasmas having a substantially uniform Maxwellian temperature distribution in a plasma column in a toroidal vacuum chamber. In this regard, these plasma confinement means have previously been designed to heat and confine a relatively warm to holt bulk plasma, in which case the attainment of thermonuclear reactions requires the meeting of the well-known Lawson criterion, i.e., n.sub.i .tau..sub.E (the product of the ion density and plasma energy confinement time), as defined above. Should these heretofore known plasma confinement and heating means, which are incorporated by reference herein and used in accordance with this invention, be adapted to confine a cold triton plasma, this invention produces fusion reactions therefrom by injecting a neutral beam thereinto. In this regard, the well-known Lawson criterion is greatly relaxed in accordance with this invention. To this end, in connection with a generalization of Lawson's criterion, one case is provided by this invention where the bulk plasma temperature, comprising the T.sub.e (electron temperature) and the T.sub.i (ion temperature), is maintained by injection of a neutral beam of ions that gives rise to an energetic ion component of density n.sub.n <<n.sub.i and initial W.sub.o >>T.sub.e, T.sub.i, these terms being defined for ease of reference as follows:

#T.sub.e =electron temperature of bulk plasma