Patent Number: 043476210
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENTS As will be appreciated from the fact that several embodiments of apparatus are illustrated and described in which the concepts of the invention may be practiced, significant latitude exists in the designing of apparatus within the scope of the invention, and the apparatus illustrated and described herein is indicative of the structural relations and features considered most advisable in the practice of the invention. FIG. 1 is an elevational, diametrical, sectional view of crossed-field nuclear fusion apparatus in which the invention may be practiced, and wherein the configuration of the reaction chamber is linear. The illustrated apparatus includes a body 10 comprising a central cylindrical core 12 and end portions 14; throughout this body there are present lithium or a lithium-bearing material which in absorbing the high kinetic energy neutrons breeds atoms of the heavy hydrogen gas tritium for subsequent use as a fusion fuel, and accepts kinetic energy, converting it to heat, which on being recovered and removed by a circulating coolant becomes useful energy. The coolant, which circulates in coils or channels 16 through this body, may be hot liquid lithium, or it may be another fluid or gas, for example helium, if the material of the body is a solid substance consisting of or containing a compound of the lithium required to breed tritium. The cylindrical core 12 is encased within the inner cylindrical electrode 18 (which might alternatively be the positive electrode). Neutron-stopping substances other than lithium may be used. Body 10 is recessed at 20, between its end portions 14, to define the reaction chamber 22 in radial alignment with the length of the inner electrode 18, and the outer dimension of the chamber is defined by the annular cylindrical outer electrode 24 which is axially aligned with the inner electrode, and in spaced radial relationship thereto to form the chamber 22. The reaction chamber is terminated at its ends by disks 26 of electrically insulating material that fit inside the ends of the outer electrode 24 and have central openings such that the disks fit over the inner electrode 18. Vacuum pumping means, not shown, are provided to maintain an extremely high vacuum in the reaction chamber 22 so that the only gaseous substance present in significant degree is the fully ionized gas in which the fusion occurs. A neutron absorbing "blanket" 28 of cylindrical configuration surrounds the reaction chamber 22 adjacent the outer cylindrical electrode 24. The purpose of this blanket is to prevent high-energy neutrons from reaching and causing damage to the portions of the apparatus exterior to it and the blanket is of length greater than that of the reaction chamber and of significant radial dimension. The absorption material comprising the blanket must have a maximum neutron absorption capability, as provided by the metal gadolinium, in order to keep the overall outer diameter of the apparatus as small as possible. Fluid cooling and recirculation conduits also exist within the blanket 28, to recover and remove as useful heat the kinetic energy generated in the absorption of the neutrons. A thermal insulating material 30 surrounds the neutron absorption blanket 28, and an electric coil 32 is wound upon the insulation 30. A negative electrical potential is imposed upon the inner cylindrical electrode 18, while a positive electrical potential is connected to the outer electrode 24, or alternatively, these electrical polarities might be interchanged; the difference in the potentials between the electrodes 18 and 24 is several tens of thousands of volts. Thus, a strong and essentially radial electric field will exist within the nuclear reaction chamber 22. The coil 32 is also connected to an electric supply source wherein the coil will produce a very strong magnetic field within the chamber 22 having paths of magnetic flux which are at right angles to the electric field direction producing strong crossed electric and magnetic fields within the reaction chamber. The lines or tubes of magnetic flux are generally parallel to the axis of symmetry of the structure, within the reaction chamber 22. As shown by the arrows in FIG. 1, the stream of fusible ions and space charge-neutralizing electrons circulates generally circumferentially and is confined within the chamber 22 intermediate the electrodes 18 and 24. If the fusion reactions are such as to produce significant charged particle fusion products, as for example the deuterium-deuterium reaction and the lithium and boron-11 reaction, and the inner electrode is negative, the circulating stream would preferably be located closer to the more negative inner electrode than to the other positive electrode 24, as then positively charged fusion products originating within the stream and moving outwardly will penetrate against a substantially larger voltage than those moving inward will pass through, and since their initial generation will be random there will be a net direct electric power generation. Also, for such reactions resulting in positively charged fusion products, the ion and electron stream can be introduced and maintained, at a range of electric potentials substantially lower than the potentials of either of the two electrodes, so that all such positively charged fusion caused particles will, after production, move to one or the other electrode against a substantial electric potential, thus causing direct generation of electric power, as well as producing usable heat by being stopped at the electrode surfaces. For such positively charged particles do not penetrate through the electrodes to cause damage farther on, in contrast to neutrons which readily penetrate the electrodes and must be absorbed farther on. The stream of fusionable ions and space charge neutralizing electrons circulating within the chamber 22 are preferably introduced into the chamber by a plurality of channels 34, FIGS. 2 and 3, each channel having an outlet 36 substantially tangentially related to the nuclear reaction chamber 22. As later described, the channel outlets 36 are oriented in a circumferential or tangential direction in order to aid the entrance of the particles into the strong crossed electric and magnetic fields within the chamber, in that with this orientation of the outlet the charged particles emerge already moving under the crossed field influence within the channel in the direction of the circulation within the reaction chamber. Preferably, the channels 34 are each of a rectangular cross sectional configuration, as will be apparent from FIG. 6, having edge portions 38 formed of an insulating material. One of the elongated channel sides, as indicated at 40, is constructed in the form of a negative electrode, while the diametrically opposite elongated channel side 42 constitutes a positive electrode. Conductors, not shown, are connected to the channel wall electrodes whereby suitable polarities are imposed thereon. When, as in FIG. 3, a plurality of channels 34 is used, the channel side having the more negative potential, of any of the channels, will be at essentially the same potential as the channel side having the more positive potential of the adjacent channel inward from it, for the case where the outer fusion chamber electrode is the positive one. Thus there is established at stream outlet from the channels a potential gradient across the entire combination of streams, corresponding to the potential gradient required to produce the parallel-to-one-another crossed field advance circulation of the several streams. This sequence of potentials, and the potentials on the inner and outer electrodes, and other needed electrical provisions, will be such as to cause there to exist a strong essentially radial electric field in the region between the outer electrode 24 and the outer face of the outer stream, and a similarly strong radial electric field between the inner electrode 18 and the inner face of the inner stream. These strong radial electric fields between the electrodes and the faces of the streams well separated from them serve very important functions in the confining of the streams to their loctions of origin at the outlets from the entrance channels. Adjacent each edge 38 of the channel, and within the confines thereof, are located a pair of spaced wire or tubular grids 44. The inner grids or tubes 46 are provided with potentials positive to the potentials of the nearest adjacent stream region, in order to reverse random motions of ions causing the ions to be repelled back into the flowing stream of ions and electrons. A negatively charged grid 48 is also located in each channel end region, beyond the positively charged grid array, with grid wires given potentials negative to the potentials of the nearest adjacent stream, to repel electrons endeavoring to escape from the stream which have passed through the inner grid 46, causing the electrons to move back into the stream. The actual design details of these grids or arrays of tubes, and choices for voltages applied to the several grid wires or tubes, will depend on design details of the ion and electron stream passing along the channel, including matters of division of ion kinetic energy as between the crossed field advance velocity along the stream and other components of their motions, the kinetic energies of the electrons, collision rates with the stream as affected by particles densities, energies, and types of ions. FIG. 4 schematically illustrates the formation of the stream 50 of fusible ions and space charge neutralizing electrons injected into the nuclear fusion chamber 22. In producing this stream of particles it is necessary that the high energy ions have a high particle density as they enter into the circulation within the fusion chamber, and the ions must be accelerated to high values of kinetic energy before entering the entrance channel where they mix with electrons. The ions are generated by an ion source, actually ten separate ion sources, schematically represented at 52, which includes a grid 54 through which the ions pass, free of electrons. Various state-of-the-art sources exist that are adequate for use in this invention; all of them involve producing a gaseous conducting plasms at far below atmospheric pressures in which ionization results from the passage of electric current, in the form of a flow of electrons, between a positive and a negative electrode, and with use of a grid structure, possibly a multiple-grid structure, at one face of the plasma enclosure that encourages ion emergence while preventing electron emergence. One such ion source that has been used successfully in research toward controlled nuclear fusion employs a multiplicity of hot filaments to provide the electrons whose acceleration by the plasma entrance fields gives them requisite ionizing energy. In another type of ion source the ions are drawn electrically from magnetically collimated arcs in the appropriate gas, as for example deuterium gas. Whatever the particular ion source, the ion stream is accelerated to the desired kinetic energy of from 10,000 to 20,000, or perhaps more, electron volts by passage through the requisite accelerating fields assigned by state-of-the-art ion optical methods, and thence pass adjacent a plurality of electron sources 56 located at the entrance to the crossed field channels 34, with parallel to one another joining of ion streams from different ion sources at successfully different potentials, so that after being accelerated to a common kinetic energy of forward motion they will form a stream having a potential gradient as desired to produce the cross-field advance within the channel. As shown in FIG. 5, the electron sources 56 can consist of a plurality of charged hot filaments 58 and associated accelerating grids 59 wherein the electrons emerge from these sources at kinetic energies of a few hundred electron volts prior to merging with the passing ion stream thus providing the space charge neutralization for the stream. As represented by dotted line 62, the region in which the ions and electrons merge, is subjected to a magnetic field of conventional strength in engineering apparatus, being several thousand gauss, and as the stream of ions and electrons moves into and through the channel 34 the stream will be confirmed within appropriate boundaries, not reaching the edges of the channel, by the circumstances of its introduction into the channel, in particular the potentials of the stream portions at their locations of merging and channel entrance, as governed by accelerating grids 60 and the ion and electron optics of the stream environments. With reference to FIG. 1, a stream exit channel 64 communicates with the right end of the chamber 22, whereby the circulating stream of particles may be removed from the chamber after passing therethrough, or there may be at that location a plurality of such channels 64, comparable with the use of a plurality of entrance channels 34. The exit channels 64 may consist of a rectangular channel construction as shown in FIG. 6, having an entrance for receiving the ions and electrons which have reached the right end of the reaction chamber; if there are several channels their several potentials are maintained at the potentials corresponding to the portions of the stream they are to receive. In the preferred embodiment the ions and electrons pass through the injection channels 34 at a very high total kinetic energy of the ions, imparted to the ions by the ion optical system outside the region of the very strong magnetic field of the reaction chamber. Each channel stream contains space charge neutralizing electrons at a density equal to that of the ions. The electrons' energies must be high enough to prevent any significant recombination with the ions to create neutral gas particles, but the electrons will initially be introduced into the stream with kinetic energies very much lower than those of the ions. As the crossed-field advance velocity of the electrons is the same as that of the ions, the two kinds of particles will pass through the channels at equal rates, carrying equal and opposite electric currents, so that the net current is zero in each injection channel. It is the intent that for the portion of the injection channel 34 that lies within the strong magnetic field, passing through the neutron-absorption blanket 28 and at the point of orientation for proper delivery of the stream into the reaction chamber, the major portion of the kinetic energy of the ions will be in the sloping components of the tightly-looping trochoidal or quasi-trochoidal motions characteristic of charged particle advance when the kinetic energy corresponding to the crossed field advance velocity is a small fraction of the particle's total kinetic energy. The cross sectional extent of the channel, in the direction of the applied electric field, is made large enough so that the radius of the looping component is a small to moderate fraction of the extent of the channel in this direction, and so also to the channel extent, at the existing values of ion energies, magnetic field strength, and potential gradient in the stream. In the portion of the injection channel that lies outside the region of very strong magnetic field, where the magnetic flux density is relatively low, being a few thousand gauss, the crossed field advance velocity is high, with essentially all of the kinetic energy of the ions being in the crossed field advance velocity. Thus the kinetic energy in the looping component of the ion motion is very small, so that the departure from straight line motion along the channel is trivial. Where the channel passes between the turns of the main coil 32, it is exposed to an extremely steep increasing gradient in the magnetic flux density. By properly relating the geometry and dimensions of the channel to the voltage thereacross in the region of this steep gradient, the transition of the motion of the ions of the stream from essentially straight line advance motion to a much slower tightly looping motion can be accomplished without harmful enlargement of the stream cross section. As an example, at a strong magnetic field flux density of 200,000 gauss and an electric field strength of 10,000 volts per centimeter within the stream of charged particles in the portion of the channel 34 inside the main coil 32, the guiding centers of both kinds of particles have a crossed field advance velocity along the channel of 10.sup.6 volts per meter divided by 20 webers per square meter, giving 50,000 meters per second as this advance velocity along the channel. For deuterons, with an ion-to-electron mass ratio of 3669, the square root being 60.6, this gives a kinetic energy content in the crossed-field advance velocity of 26 electron volts. If the total kinetic energy per ion, given in its ion optical acceleration, is 20,000 electron volts per deuteron, an acceptable order of magnitude for fusion, this leaves substantially all of the kinetic energy in the looping component of the motion in this within-the-main-coil portion of the entrance channel. For deuterons the radius of the looping component of the motion at this kinetic energy and in this magnetic field is 1.44 millimeters. It is desirable to have the ion and electron density lower in this portion of the entrance channel than in the streams within the reaction chamber, both to avoid occurrence of fusion before passage through the neutron blanket is completed, and as an aid to controlling random motion movement of the charged particles in the magnetic field direction toward the ends where their escape is prevented by the grids 44. At an illustratively desirable ion and electron density of 2.times.10.sup.13 per cubic centimeter in this within the main coil portion of the entrance channel, the current flow carried by the ions is 2.times.10.sup.19 per cubic meter multiplied by 50,000 meters per second to give 10.sup.24 ions and electrons flowing along the stream per square meter per second; at 1.6.times.10.sup.-19 coulomb per ion this is 1.6.times.10.sup.5 amperes per square meter, or 16 amperes per square centimeter, of current carried along th channel by the ions, with an equal and opposite current carried by the negatively charged electrons, the net current in the channel being zero. At the point of injection into the circulating stream within the nuclear reaction chamber 22, with a plurality of channels 34 being used, the several channels will have differing average electric potentials. For the design in which the outer electrode 24 of the reaction chamber is the positive electrode, the channel 34 having the outermost radial position will be at the higher potential, the next one somewhat less positive, and so on. Also, as described elsewhere, within each channel's stream as it exits from the channel outlet 36 there is a potential gradient with the potential declining inwardly for this example. Thus as the several streams enter the reaction chamber 22 there appears in this annular chamber a radial potential distribution generally declining from a highest value at the outer electrode, which is at a potential substantially higher than that at the side of the outermost stream, to a lesser value at the inner electrode 18, which would be in this illustration at a potential substantially lower than that at the side of the innermost stream. There will be a considerable radial distance between the outer side of the stream 50 and the outer electrode 24, and similarly a considerable radial distance between the inner side of the stream 50 and the inner electrode 18; however, there need be no separation radially between the several stream of channels 34 after they enter the nuclear reaction chamber 22 and begin their circumferential circulation at right angles to both the magnetic field and the applied electric field. This illustrates a basic aspect of the invention, i.e., establishing the potential distribution within the stream at stream entry by design and operation of the apparatus, and maintaining this potential distrubution during the circulation within the reaction chamber, if necessary by control of charge distribution at or beyond stream edges, as for example by circulating streams of electrons outside the main stream or streams. By establishing and maintaining a potential distribution in which the potential gradient is less steep within the inner stream 66, FIG. 3, than within the outer stream 68, the crossed field circulational advance of the inner stream can be made slower than that in the outer stream so that time for circulation around the smaller inner stream path be made the same as for that around the longer outer stream path. Confinement of the stream of particles within the entrance channels 34 may be understood in terms of ion-optical perceptions which indicate the field forces exist that compel motion to be in the cross-field direction, with but little departure therefrom if the channel parameters are properly designed, or one can think in terms of "magnetic pressure," the concept being that the charged particles can cross magnetic flux lines only to a very limited extent in the absence of electric fields in the direction of the longer cross sectional dimension of the channel. Such fields do not exist outside of the ion and electron streams. The same considerations apply to the continuing existence of circumferential streams after emergence from the entrance channels 34 into the circulating streams in the reaction chamber. As to the circumferential circulation within the annular reaction chamber 22, provisions are made to assure that the stream 50 during each circulation around a circumferential path shifts axially to a limited extent in the direction of the magnetic field provided by the main coil 32, to provide an advancing of the stream circulation in that direction. Thus, the total path within the reaction chamber will correspond to a helix with a pitch small relative to its diameter and with the axis of the helix being the same as the axis common to the two electrodes 18 and 24; thus these helical paths of the charged particles' guiding centers lie in the annular region between the two electrodes and are concentric with the cylindrical shapes of those electrodes. This advance from turn to turn around the helical paths is provided by giving the magnetic field a small circumferential component. This can be accomplished in the disclosed embodiment by passing a direct current of appropriate strength along the length of the inner electrode 18 in the opposite direction to the small axial component of the current in the main coil 32 that produces the strong magnetic field. The combination of this circumferential component of the magnetic field with the basic strong field parallel to the axis of the electrodes is called a "poloidal" magnetic field. A variation in the apparatus wherein the invention concepts of the invention may be practised is shown in FIG. 7, wherein the apparatus is in the form of a two part toroid. Preferably, when the apparatus is in the form of a toroid it would comprise a complete toroid wherein an annular reaction chamber between two toroidal electrodes exists, whereby the stream of particles may continually move along curved axis helical paths about a 360.degree. elongated circuit of the helical axis. However, because of the need to support the inner electrodes such a construction is not practical. In FIG. 7 the two halves of the toroid are designated by the reference numerals 70 and 72, and are identical in construction and identical numeral references are utilized in the description thereof. The apparatus portions 70 and 72 include an arcuate inner small diameter tubular electrode 74 which is of substantially a 180.degree. configuration, and at its end is mounted upon the insulating-material mounting plates 76 radially disposed with respect to the general configuration of the apparatus. The tubular electrode 74 may be positively charged, and an annular reaction chamber 78 is defined by this electrode and the outer negatively charged tubular electrode 80 circumscribing the inner electrode. The outer electrode is also mounted on the plates 76. Alternatively, the inner electrode may be negatively charged and the outer electrode positively charged, as the basic requirement is that there exist between them a strong applied electric field having a direction radial to the circular axis common to the two electrodes. The outer confines of the apparatus are defined by the tubular housing 82, which is of considerably larger diameter than the outer electrode 80 wherein an annular radial space exists between the housing and the outer electrode, which is filled with a high neutron absorbing material 84, as for example gadolinium and containing circulating conduits, not shown, for removing therefrom the heat resulting from stopping the high-energy neutrons. The circulation removes the heat as useful output, or there can be provisions to circulate hot liquid lithium in this space, to breed tritium as well as accepting the kinetic energy of the neutrons and converting it to heat removed by the circulation to become useful energy. Or there can be used a solid substance consisting of or containing lithium to serve to breed tritium gas, with a liquid or a gas, for example helium, circulating as the coolant to remove and provide utility from the heat, and to remove the tritium gas as it is bred. Magnetic coils 86 encompass the housing 82 for producing the desired strong magnetic field within the reaction chamber between electrodes 74 and 80. The entrance channels 88 for introducing the stream of high kinetic energy fusible ions and space charge neutralizing electrons are located adjacent the plates 76, and exiting channels 90 are located at the opposite ends of the reaction chamber for permitting the particles to be removed therefrom. Preferably, the stream of ions and electrons is introduced into the reaction chamber 78 by a plurality of entrance channels 88 as described with respect to FIGS. 1-3, and the operation of the apparatus of FIG. 7 is functionally similar to that as described with respect to FIG. 1. Of course, it will be appreciated that the advantage of the toroid construction of FIG. 7 lies in the ability to locate a relatively long chamber in a minimum of space and there is also the advantage that with the toroidal shape of the coil producing the strong magnetic field there exists an absolute minimum of stray magnetic field outside the outer housing. The circular toroid configuration is particularly suitable for using apparatus of this type in cylindrical housings such as rocket engines and the like. In FIGS. 9 and 10 another embodiment of apparatus for producing nuclear fusion in accord with the inventive concepts is illustrated. In this embodiment the apparatus is of such construction as to permit the traveling streams of high kinetic energy fusionable ions and space charge neutralizing electrons to be recirculated through a pair of nuclear reaction chambers wherein the time of persistence of the stream may be prolonged indefinitely, and the ion density may be progressively increased, and the rate and duration of neutron generation elevated with respect to prior described apparatus. The apparatus illustrated in FIGS. 9 and 10 is of a linear configuration wherein annular reaction chambers have an elongated linear axis, as in the embodiment of FIG. 1, and it will be appreciated that there are a number of structural similarities between the embodiment of FIG. 1 and that of FIGS. 9 and 10. The body 92 is formed of a material which provides absorption of neutrons and breeding of tritium gas using lithium, and the body includes internal conduits or channels, not shown, for circulation for the purpose of removing therefrom the heat generated by the stopping of the neutrons and the removal of the tritium gas resulting from the breeding. The circulant might be hot liquid lithium, or in the case of use of a solid substance containing lithium or a lithium compound for tritium breeding, the circulant might be some other liquid or gas, for example helium gas. Centrally, the body is of a reduced cylindrical configuration surrounded by the inner negative electrode 94. A cylindrical positive electrode 96 of tubular configuration circumscribing electrode 94 in radially spaced relationship thereto defining an annular inner nuclear reaction chamber 98. A second outer annular nuclear reaction chamber 100 is defined in radial alignment with the chamber 98 by an annular cylindrical negative electrode 102 disposed adjacent electrode 96, and an annular outer cylindrical positive electrode 104 in spaced relationship to electrode 102 defines the outer confines of the outer reaction chamber 100. As the outer electrode 96 of the inner chamber 98 and the adjacent inner electrode 102 of the outer chamber 100 may be at very different electric potentials, electrical insulation must be provided between them. An alternative design might be one in which for both reaction chambers the outer electrodes are electrically positive, and the inner ones negative, or even a design in which for one chamber the outer electrode is positive relative to the inner, and for the other chamber the outer electrode is negative relative to the inner; any of these arrangements would provide the requisite radial electric fields in both chambers. Both of the chambers 98 and 100 are circumscribed by the cylindrical annular blanket of material 106, having high neutron-absorbing characterstics, such as gadolinium, and the blanket contains cooling conduits, not shown, for remvoing and usefully employing the heat therefrom generated by the stopping and absorption of the neutrons. The thickness required in the neutron absorbing blanket, and the need for tritium breeding in the inner core body 10 of FIG. 1 and 92 of FIGS. 9 and 10, also the need for tritium breeding and the thickness of the absorbing blanket 84 of the FIG. 7 embodiment, depend on the types of fusionable ions used in the reaction chamber. The embodiments here presented, emphasizing tritium breeding and a relatively thick blanket to protect the main coil from damage by exposure to neutrons, are described primarily with reference to the use of a mixture, in nearly equal proportions, of tritium and deuterium as the materials from which the ions are formed. Conceivably also there might be employed lithium and "boron 11" for which the fusion results only in the production of positively charged particles, no neutrons at all. The positively charged particles cannot penetrate the electrodes to pass beyond them into the main coil; therefore no neutron-absorbing blanket would be required, although the cooling of the metal surfaces where the high-energy charged particles are stopped becomes necessary; in principle, also, some of the energy can be recovered by direct electrical conversion resulting from penetration of the positively charged particles against a substantial potential. By the use of such materials that would greatly lessen the thickness of the neutron absorbing blanket, or possibly even eliminate it, the size required of the apparatus can be greatly reduced, and the demands for providing excitation of the strong magnetic field also greatly reduced, because of the lessened volume in which the strong magnetic field must be produced. Because of these reasons, the possibility of using the embodiment of FIG. 9 in a nuclear-fusion engine for space vehicle propulsion is attractive, in that with no requirement for tritium breeding the dimensions can become small, and for the space environment the existence of the extensive stray field of the linear configuration would be of less significance as a practical matter than for earth-bound applications. Such an application would become attractive in view of the capabilities of this invention for controlling the kinetic energies and densities of the ions of the stream rather straight-forwardly up to high values, and in the recirculating mode of FIGS. 9 and 10 to have the ions remain in the active state for long periods of time. With reference to FIGS. 9 and 10, a thermal insulation material 108 surrounds the neutron absorbing blanket 106, and the electric coil 110 is wound upon the insulation for providing a strong magnetic field within the chambers 98 and 100. A stream 112 of high kinetic energy fusible ions and space charge neutralizing electrons is introduced into the inner chamber 98 by channel 114, and the particles of the stream are generated in a manner identical to that previously described. The particles introduced into the left end of the inner chamber 98, FIG. 9, will move about the inner electrode 94, and move with helical travel toward the right. It is desired that the stream of ions and electrons be transferred from the inne chamber 98 to the outer chamber 100 adjacent the right end of the chamber 98, and for this purpose a transfer channel 116 or a plurality of transfer channels, establishes communication between the right ends of chambers. The transfer channel 116 is of a rectangular cross sectional configuration identical to that shown in FIG. 6, but is of an arcuate longitudinal shape, FIG. 10, and includes a tangential inlet end 118 for receiving the stream of particles within the chamber 98, and an outlet end 120 whereby the stream of particles is tangentially introduced into the chamber 100; in the transfer channel the particles of the stream have their guiding centers constrained by the requirement for crossed field advance to move while within the chamber from the point where they enter it from one chamber to where they exit into the other; the transfer channel is a crossed-field channel. The electric potential and the circumferential component of the magnetic field are such as to cause the stream of ions and electrons introduced into the right end of the chamber 100 to move toward the left end, and as will be noted in FIG. 9, a second crossed field transfer channel 122 is located at the left end of the chambers 98 and 100, establishing communication therebetween whereby particles within chamber 100 may be transferred inwardly into the chamber 98, and the travel cycle of the particles repeated. The channel 122 is of similar construction to channel 116, and is of a construction identical to FIG. 6, being a crossed field transfer channel, including a tangential inlet end within outer chamber 100, and a tangential exit end within chamber 98. The apparatus also includes a crossed field stream exit channel 124 disposed adjacent the entrance channel 114, and the exit channel is located adjacent the left end of the outer reaction chamber 100 whereby stream particles may be removed from the outer chamber as desired. The channels 114 and 124 merge into channel 122 to tangentially introduce and receive the stream particles. Thus, by controlling the rate at which particles exit the chamber 100, and the rate at which they enter the inner chamber 98, the density of particles within the stream 112 recirculating within the chambers can be regulated. The control of the particle flow through the various channels is controlled by electric potentials and other known means. The apparatus of the invention may be operated by introducing a stream of high kinetic energy fusible ions and space charge neutralizing electrons into the chamber 98 via entrance channels 114 for a sufficient time to permit particles to "fill" the chambers 98 and 100, and after the time that the chambers are filled the entrance of stream particles terminates and the stream continues to recycle through chambers 98 and 100, and no exiting of stream particles via the exit channel 124 occurs. However, if desired, during the recirculation of the stream, even though the stream is dispersed throughout both chambers, additional high kinetic energy ions and space charge neutralizing electrons may be introduced into the chambers via channels 114. It is possible after a desired portion of the stream exits through the exit channel 124, to substantially linearize the motion and then pass the stream through apparatus of a magnetohydrodynamic nature which will recover into electrical form a large part of the kinetic energy contained in the motions of the ions that have exited. Just as FIG. 7 illustrated an embodiment using toroidal geometry of the method and designs and operational functioning as described for FIG. 1, so there can be a toroidal embodiment of the recirculational method and designs and operational functioning as in FIGS. 9 and 10. Thus in such an embodiment there are two pairs of chambers, each 180.degree. semicircular in extent, thus together completing the 360.degree., of toroidal design annular reaction chambers, one entirely enclosing the other, and each with a toroidally designed outer electrode and inner electrode at opposite potentials. The stream circulation would be in basically helical form within one of these around a helix whose axis is bent to form a semicircle, to the end of this channel where it meets the mounting plates; then by a crossed field transfer channel the stream is transferred to the other reaction chamber where its travel brings it back to near the mounting plate where the entrance channel is located. The reversing of the direction of travel is due to reversal of the circumferential component of the magnetic field, and this is accomplished by proper choice of magnitudes and directions of current passage in the chamber-bounding electrodes along their semicircular lengths. In the foregoing description the movement of the ions within the annular reaction chamber is described as being of a tightly-looping quasi-trochoidal type. This phraseology is used to describe the looping action of the ions resulting from the fact that the kinetic energy in the small diameter looping components of the ion motions greatly exceeds the energy in the relatively slow crossed field advance motion. The kinetic energy in the looping component of the troichoidal motion is at least ten times greater than the kinetic energy in the crossed field advance motion, and as used in this description, the tightly looping quasi-trochoidal motion is to be understood in this context. Of course, the "tighter" the loops of the ion movement the greater the frequency of collisions of particles within the reaction chamber, and higher energy ratios than ten are of advantage. However, the concepts of the invention are present with an energy ratio of ten, and the phraseology employed in this description, and the claims, is to be understood to include the energy ratio of ten to one in respect to the ion movement. The high kinetic energy ions are given their energy before introduction into the annular reaction chamber which has a primarily axial strong magnetic field and an essentially radial electric field, and the ions assume in the reaction chamber a tightly looping quasi-trochiodal type of motion. The likelihood of fusion collisions occuring is significant in that the looping movement of the ion motions exceeds, at least by a factor of ten, and to factors of tens or tens of thousands, or more, the kinetic energies in the relatively slow crossed field advance motions with which the ions circulate circumferentially around the axis of the reaction chamber, and this motion of the ions distinguishes over prior fusion approaches. The word "quasi" as employed in defining a quasi-trochoidal ion motion signifies that the trajectories are trochoidal motions relative to guiding centers whose paths are arcuate rather than being along straight lines. The novel aspects of the invention include the introduction of the energetic ions into the reaction chamber as ions, with space-charge neutralization occuring by incorporating electrons into the stream as free electrons subsequent to giving the ions their energy. Further advantages result from the employment in the reaction chamber, by crossed field means, of the trochoidal motion of the ions in which the kinetic energy in the looping motion greatly exceeds that in the crossed field advance motion. Further distinction of the invention over known devices exists in the introduction into and retention of the ion and electron stream within a radially delimited region substantially separated from both walls of the reaction chamber providing a substantial confinement in spite of the presence of space-charge waves in the stream. Additionally, the provision, by means of the crossed field advance of the guiding centers along helical paths due to the slight poloidal component of the magnetic field for a continuous and controllable rate of flow of the ion and electron stream into, through and out of the reaction region, including provision for continuous recirculation through the chambers and return to the first chamber also provides a continuous operation not heretofore known. The disclosed method and apparatus make it possible for the operator of the equipment to determine independently of one another the three critical attributes of a magnetically confined stream of ions and electrons, namely, the average ion energy; the density of the charged particles in the stream; and the time of exposure of the ions to the conditions favorable to fusion. It is appreciated that various modifications to the inventive concepts may be apparent to those given the art without departing from the spirit and scope of the invention.