Magnetic confinement nuclear energy generator

A fusion reactor (10) includes a sphere (12). Structure (20) is disposed within the interior of the sphere (12) for producing a magnetic field. Structure (24, 26) is circumferentially disposed around the exterior of the sphere (12) for producing a countermagnetic field. Structure (28, 32, 38, 46a) is provided for injecting a gas containing fusible ions into the sphere (12). Structure (30, 32, 38, 46) is also provided for heating the gas within the interior of the sphere (12). Structure (62, 64, 66, 68) is provided for extracting heat from the sphere (12).

TECHNICAL FIELD 
This invention relates to the generation of energy from the fusion of 
atomic nuclei, and more particularly to a magnetic confinement nuclear 
energy generator. 
BACKGROUND ART 
It is known that individual nuclear particles are so constituted as to 
permit fusing of the lighter nuclei. Fusion of lighter nuclei is 
accompanied by release of energy. Of particular interest, is any fusion 
reaction in which power can be produced in quantities greater than the 
power consumed in establishing and maintaining the reaction. There are 
over thirty reactions now known to be possible. The most appealing 
reactions are those which involve the heavy hydrogen isotopes, deuterium 
and tritium, because they tend to have the largest fusion reaction cross 
section at the lowest energies. Many possible reactions are well known. 
For example, Van Norstrand's Scientific Encyclopedia, Fifth Edition, 
Reinhold Company, New York, N.Y., 1976, at page 1656, et seq., discusses 
various aspects of the possibilities for producing a net gain in power 
from fusion reactions and briefly describes some of the attempts to 
perform such reactions with a net power gain. 
Plasma research has received concentrated attention, but the formidable 
task of plasma containment has yet to be solved. In avoidance of the 
problems of containment, a more recent approach involves laser-induced 
fusion. In its simplest form a focused energetic laser beam is brought to 
bear on a small deuterium-tritium pellet for heating to fusion 
temperatures. Efforts on this and on other fronts such as those involving 
containment have been steady in response to high incentives. 
Thus, while many of the possibilities have long been known and have been 
widely attacked through various approaches towards achieving net power 
gain from fusion, the challenge remains unsatisfied. 
A central problem of deuterium fusion for power production is that of 
raising a small mass of ionized deuterium or a mixture of deuterium and 
tritium to the necessary reaction temperature while maintaining the 
density of the plasma and temperature long enough for a sufficient portion 
of the hot ionized gas to proceed with a nuclear reaction. The necessary 
temperature required is of the order of 10.sup.8 K.degree., such that no 
solid state matter can maintain mechanical integrity while in close 
contact with the reaction. It is therefore necessary to either confine the 
reacting plasma with a magnetic field or to pulse the reaction so rapidly 
that inertial forces from rapidly moving high temperature gases can be 
used to provide the confinement forces for the short time necessary. 
Magnetic confinement of the reacting plasma has been attempted in many 
forms. Such previously developed forms have suffered from instabilities 
which have allowed the hot plasma to leak through the confining fields too 
rapidly. A deficiency in prior systems is the amount of thermodynamic 
equilibrium time required because heat is frequently introduced by heating 
the electrons of the plasma. If the plasma is thin, the thermodynamic 
equilibrium time necessary for the positive ionic temperature to equal the 
electron temperature where the reaction can occur is too long compared to 
the stability time. The particle leak rate of the magnetic confinement 
system must also permit a confinement time longer than the instability or 
the electron-ion thermodynamic equilibrium time. 
Several factors of a magnetic confinement system are important for allowing 
the required reaction time and plasma density to be reached. These factors 
include the field strength and gradient of the magnetic field, the 
particle density and density gradient of the plasma and the stability time 
of the plasma confinement. All these factors interact and influence the 
confinement time. 
A need has thus developed for a fusion reactor which greatly extends 
confinement time and increases the effectiveness of the other factors 
involved in nuclear fusion utilizing a confinement system which will 
provide long confinement time. Such a natural system is the Van Allen 
belts of radiation around the earth. In these belts an ion plasma of 
sufficient temperature to sustain deuterium-deuterium fusion is confined 
by a small magnetic field with a relaxation time of many months. The Van 
Allen belts of radiation are created by charged particles reflected in a 
north-south oscillation by "magnetic mirrors" formed by the increasing 
intensity of the magnetic fields in the higher latitudes of the earth. 
This natural system of magnetic mirrors makes use of fields on the outside 
of the earth's "magnet". 
A need has thus arisen for a fusion reactor utilizing a magnetic 
confinement system of magnetic mirrors with the "natural" geometry 
reproduced on a realizable scale to increase plasma density without a 
detrimental reduction in stability time. A need has further arisen for 
such a magnetic system in which provision is made for an input of heating 
energy to raise the temperature of the plasma to the required reaction 
temperature. 
DISCLOSURE OF THE INVENTION 
In accordance with the present invention, a nuclear fusion generator is 
provided in which a magnetic confinement system is utilized which 
substantially eliminates the problems heretofore associated with fusion 
reactors. 
In accordance with the present invention, a fusion reactor is provided. The 
reactor includes a sphere. Structure is disposed within the interior of 
the sphere for producing a first magnetic field. Structure is disposed 
circumferentially around the exterior of the sphere for producing a second 
magnetic field which is antiparallel to the first magnetic field. 
Structure is provided for injecting a gas containing fusible ions into the 
interior of the sphere. The reactor further includes structure for heating 
the gas within the interior of the sphere to promote collisions between 
ions within the sphere. Structure is responsive to the energy produced 
from the ion collisions within the sphere. 
In accordance with another aspect of the present invention, a fusion 
reactor includes a sphere. A superconducting coil is disposed within the 
sphere for producing a high magnetic field within the sphere. A pair of 
Helmholtz coils are disposed circumferentially around the exterior of the 
sphere for producing a second magnetic field which is antiparallel to the 
magnetic field produced by the superconducting coil. Structure is provided 
for injecting a gas containing fusible ions into the sphere. A microwave 
power supply is provided for heating the gas within the interior of the 
sphere to promote collision between the ions within the sphere. Structure 
is further provided which is responsive to the energy produced from the 
ion collisions within the sphere.

DETAILED DESCRIPTION 
Referring simultaneously to FIGS. 1-4, a diagrammatic illustration of the 
present fusion reactor, generally identified by the numeral 10, is 
illustrated. Reactor 10 comprises a sphere 12 having an equator 14 and a 
magnetic axis 16. Sphere 12 has a radius, r (FIG. 3), of approximately, 
for example, one meter. A magnetic field is produced within sphere 12 
utilizing a superconducting coil 20 which is suspended at the center of 
sphere 12 by superconducting leads 22 (FIG. 4). Magnetic axis 16 
represents the axis of the system of the present invention whereas the 
equator 14 is defined as the perimeter of the mid-plane perpendicular to 
the magnetic axis 16 of superconducting coil 20. 
A pair of Helmholtz coils 24 and 26 are disposed circumferentially around 
the exterior of sphere 12 to produce a magnetic field antiparallel to the 
magnetic field produced inside sphere 12 by superconducting coil 20. The 
field produced by Helmholtz coils 24 and 26 increases the magnetic field 
in the outer regions near equator 14 of sphere 12 and ensures a uniform 
field in the region of equator 14. 
A gas containing fusible ions such as deuterium or a mixture of deuterium 
and tritium is introduced into sphere 12 from an input source 28 (FIG. 1) 
through input horns 32 which are circumferentially disposed around axis 16 
of sphere 12. The gas within sphere 12 is heated utilizing an input source 
30 which supplies microwave power to a wave guide 38. Wave guide 38 is 
interconnected to horns 32. 
FIG. 5 illustrates one horn 32. The aperture of each horn 32 is divided 
into an odd number of sections 46 across the direction at right angles to 
equator 14. Septa 48 separate sections 46. Central section 46a of horn 32 
is interconnected via wave guide 38 to input source 28 for receiving a gas 
supply of nuclear fusible fuel gas such as, for example, deuterium or a 
mixture of deuterium and tritium. The remaining sections 46 of horn 32 are 
interconnected via wave guide 38 to input source 30 to receive microwave 
power which functions to heat and ionize the gas within sphere 12 thereby 
creating a hot plasma. The microwave power from input source 30 for plasma 
heating can be produced from standard power sources of 80% efficiency. 
The sections 46 of horn 32 on either side of section 46a allow for a 
variation of phase of microwave power from input source 30 across the 
aperture of horn 32. FIG. 5 illustrates septa 48 separating sections 46 of 
horn 32 having phase angles of 0.degree., .theta..degree. and 
2.theta..degree. on one side of equator 14 and 0.degree., -.theta..degree. 
and -2.theta..degree. on the other side of equator 14. This variation in 
phase of the microwave power is along the direction of the stationary 
magnetic field lines of superconducting coil 20 in the region of the 
plasma excitation. 
As shown in FIG. 3, the plasma variation produces a magnetic wave which 
sweeps plasma 56 away from the mid-plane and along the static magnetic 
field flux lines produced by superconducting coil 20 towards the cusps 20a 
and 20b of superconducting coil 20. This action causes an increase in the 
component of the kinetic energy of the plasma within sphere 12 parallel to 
the magnetic flux relative to the component perpendicular. This action 
further allows a mirror ratio in the magnetic field to approach the limit 
imposed by the ratio of the high magnetic field at cusps 20a and 20b to 
the low magnetic field in the region of the microwave excitation of, for 
example, approximately 400 kgauss. Because cusps 20a and 20b are "back to 
back" the plasma leakage at these magnetic mirrors is eventually recovered 
by return to the main stream 56. 
Referring again to FIG. 3, the main magnetic field produced by 
superconducting coil 20 will guide electrons and ions along the magnetic 
flux lines towards the cusps 20a and 20b at the ends of super-conducting 
coil 20. The components of the random thermal velocities of the electrons 
and ions which lie along the flux lines will cause plasma 56 to flow into 
the magnetic cusp region 20a and 20b from all other parts of the plasma 
within sphere 12. This flow will produce an increase of pressure at the 
magnetic cusp 20a and 20b. This flow will also cause the reversal of the 
velocity components due to reflection at cusps 20a and 20b. Thus the 
pressure and corresponding velocity will be higher at the cusps 20a and 
20b within sphere 12. A sufficient input of microwave heating energy from 
input source 30 at the lowest density part of the gas volume will power 
this compression which builds up to the limit imposed by the magnetic 
pressure at cusps 20a and 20b. 
Referring to FIGS. 3 and 5, the energy produced due to the fusion reactions 
taking place in reactor 10 is extracted from the interior surface 60 of 
sphere 12. The exterior surface 62 of sphere 12 is provided with a lining 
64 of carbon, such as, for example, pyrolitic carbon. A suitable heat 
exchange jacket 66 surrounds the exterior of sphere 12. Exchange jacket 66 
is connected to a utilization unit 68 (FIG. 1). 
The present reactor 10 produces directed kinetic energy supplied by the 
moving magnetic wave to plasma 56 at the region of lowest pressure and 
density and provides dynamic adiabatic compression at the magnetic cusps 
20a and 20b to produce a density and temperature sufficient to produce 
nuclear fusion in the region of the magnetic cusps 20a and 20b on each end 
of superconducting coil 20. It can be shown that fusion takes place within 
reactor 10 and that the product of the estimated particle density and the 
confinement time will be expected to be greater than the Lawson criterion 
for the relevant system efficiency, ion mixture and ion energy. 
Assume the Lawson criteria for a deuterium-tritium ion mixture with 
energies of 10 kev to 20 kev and 40% efficiency to be 4.times.10.sup.13 
sec/cc. It will also be assumed that in the present reactor 10, the 
magnetic field in the reaction region will be 400 kilogauss. The maximum 
kinetic pressure will equal the confinement pressure of the magnetic field 
as follows: 
EQU p.sub.max =B.sub.2 /8.sub..pi. (1) 
and since B=400 kilogauss, it can be seen that: 
EQU p.sub.max =6.4.times.10.sup.9 dynes/cm.sup.2 =6.4.times.10.sup.9 
ergs/cc.(2) 
If the particles have an energy of 10 kev or 1.6.times.10.sup.-8 ergs, the 
number of particles given by p.sub.max is: 
EQU 6.4.times.10.sup.9 /1.6.times.10.sup.-8 =4.0.times.10.sup.17 
particles/cc.(3) 
To find the confinement time, an estimate is made based on the expression 
for the confinement time for the cusp configuration of a magnetic mirror. 
This time may be expected to be smaller than the time for the geometry for 
the present reactor 10. For the cusp geometry the confinement time is: 
EQU t.sub.sec =R.sub.cm.sup.2 B.sub.gauss .times.10.sup.-10 /T.sub.kev(4) 
where R.sub.cm is the radius of the cusp in centimeters, B is the magnetic 
field in gauss and T is the kinetic energy of the particles in kev. 
Based upon superconducting coil 20 having a radius of 5 centimeters and a 
length of 10 centimeters, and a magnetic flux of 400 kgauss, upon 
substituting these parameters into Equation (4) it can be seen that 
t.sub.sec =10.sup.-2 seconds. Therefore the product of the maximum number 
of particles per cubic centimeter and the estimated confinement time is: 
EQU 4.times.10.sup.17 particles/cc.times.10.sup.-2 sec=4.times.10.sup.15(5) 
which is to be compared with the Lawson criteria which is 
4.times.10.sup.13. Therefore the product of the maximum number of fusible 
particles per cubic centimeter and the confinement time estimated for the 
present reactor will fulfill the Lawson criteria. 
It therefore can be seen that the present invention provides for a fusion 
reactor for power production utilizing a magnetic confinement system in 
which the reaction temperature and plasma density can be maintained for a 
sufficient time period such that the ionized gas can proceed with a 
nuclear reaction. 
Whereas the present invention has been described with respect to specific 
embodiments thereof, it will be understood that various changes and 
modifications will be suggested to one skilled in the art and it is 
intended to encompass such changes and modifications as fall within the 
scope of the appended claims.