A Spheromak is a controlled fusion reactor design in which the fusion plasma is electromagnetically confined within a spherical electromagnetic field geometry. Deuterium plasma or deuterium/tritium plasma is injected into a spheromak. This places a small star like ball of fusion plasma inside of the spherical electromagnetic field, inside the spheromak. Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance of one atom in 6500 of hydrogen. ...

The spherical electromagnetic field deflects the plasma toward the center of the chamber, and thus compresses it, or pinches it in the center of the spherical electromagnetic field via the Lorentz force. Also the deuterium and tritium atoms, like light hydrogen atoms, possess a property called diamagnetism. The property of diamagnetism causes hydrogen atoms, including those of dueterium and tritium, to collect in the center of an electromagnetic field. In physics, the Lorentz force is the force exerted on a charged particle in an electromagnetic field or just magnetic field. ... Diamagnetism is a very weak form of magnetism that is only exhibited in the presence of an external magnetic field. ...

The core of a spheromak may be a hollow iron or steel sphere that is wrapped with up to 100,000 superconducting steel electromagnetic solenoid coils that are cooled by a liquid helium cooling jacket. As the spheromak operates, a little bit of its plasma is allowed to leak out the other side of it. This leaked plasma's energy may be tapped to generate electric power, or to provide a plasma exhaust jet for a fusion rocket engine.

The spherical electromagnetic field can have a magnitude of up 10 tesla when operated in a steady manner, or a magnitude of up to 100 or even 1000 tesla when operated in a pulsed manner for a fraction of a second. The tesla (symbol T) is the SI derived unit of magnetic flux density (or magnetic inductivity). ...

The electromagnetic field is created by running alternating electric current through the solenoid coils wrapped around the spheromak. Because plasma is an electric conductor, the alternating electromagnetic field of the spheromak will induce an electric current in the plasma via Faraday's law of induction. An alternating current (AC) is an electrical current where the magnitude and direction of the current varies cyclically, as opposed to direct current, where the direction of the current stays constant. ... Faradays law of induction gives the relation between the rate of change of the magnetic flux through the area enclosed by a closed loop and the electric field induced along the loop: where E is the induced electric field, ds is an infinitesimal element of the closed loop and...

Furthermore, high energy microwave emitters that are much more powerful than those used in microwave ovens are attached to the plasma injector gun. These microwaves and the electrical resistance heating of the plasma are used to heat it to fusion range temperature in excess of 100,000,000 degrees Celsius.

The electric current induced in the plasma will cause the electrothermal resistance heating of the plasma inside the spheromak. The electric current running through the plasma will also generate an electromagnetic field around the plasma.

The field geometry serves to confine the plasma for a fraction of a second, and also to try to achieve the electromagnetic implosion of a ball of fusion plasma inside the spherical magnetic field by deflecting it to the center of the field via the lorentz force exerted on the plasma by the spherical magnetic field of a spheromak.

The electromagnetic deflection of the plasma to the center of the spherical magnetic field will increase the density of the fusion plasma ball. So the fusion ignition strategy is:

• Heat the plasma to a temperature of 100,000,000 degrees Celsius or more.
• Increase density of plasma by using spherical electromagnetic field geometry to deflect plasma to center of field, and thus compress it in the center of the spherical magnetic field geometry.
• Use the combination of the inertia of the ball of plasma, the spherical electromagnetic bottle confining the plasma, and the diamagnetism of the the hydrogen to achieve confinement of the fusion plasma as long as possible so as to hopefully ignite nuclear fusion in the plasma.

Conclusion

Thus far, no one has built a working prototype based on this design. Only theoretical studies have been done on spheromaks currently.

If a lawson criterion value of 10^14 or higher is achieved inside the spheromak, nuclear fusion will occur in the ball of plasma inside of it. The lawson formula that applies is the three factor one of: L = Temperature in celsius * Density of the plasma * Time of the confinement of the plasma In nuclear fusion research, the Lawson Criterion is an important general measure of a system that defines the conditions needed for a fusion reactor to generate net output energy -- that is, produce more energy in the fusion reactions than is lost in thermal and other radiation out of the fuel. ...

See Also

• Tokamak
• Nuclear fusion