Tuesday, December 11, 2007

Another IEC Fusion Company: Fusion Power Generation

A couple of Columbia grads are having a go at IEC fusion under the name Fusion Power Generation, and they're looking for funding. (Aren't we all?) Alex Klein used to work at EMC2; the meat of his approach can be found on their Q & A page:
9. What is different about our approach?

- By adding a particular type of magnetic field to a traditional spherical IEC machine, using a shaped electromagnet which doubles as the accelerating cathode, we are able to dramatically lower the losses of energetic ions that limit the efficiency of traditional designs.

- The magnetic field confines electrons to the reaction region at the center of the machine; electrons enter via secondary emission from the electromagnet itself. The electrons bulk-neutralize the positive charge of the ions, and allow the ions to converge to very high densities at the center: the density can be increased by a factor of 10,000 or more over conventional IEC devices.

- The magnetic field also creates space charge lenses at the openings of the electromagnet so-called magnetic mirrors, which in turn serve to continually refocus beams of ions as they pass in and out of the core. The focusing action can be made to exactly counteract the effect of Coulomb collisions between particles, and ions can re-circulate on stable orbits thousands of times through the device without colliding with a material structure, preventing the loss of energy that limits the efficiency of conventional machines. In this way the density will be greatly increased while the input power to the device will be reduced over conventional IEC machines.

- Both effects will help solve the problems that have limited previous IEC experiments' performance.

- With higher densities, electrons and ions can arrange themselves in alternating layers of positive and negative charge, forming "virtual electrodes" that can result in yet higher densities of ions at the center of the machine, and a trapped ion population that never intersects any material structure. Evidence for this effect has previously been observed in operating IEC machine.

- The addition of a small radio frequency modulation of the cathode voltage will drive trapped ions to converge simultaneously at megahertz rates in the very center of the machine at high energies, provided a harmonic electric potential can be maintained inside the cathode, an effect called POPS (Periodically Oscillating Plasma Sphere) that has been documented in previous IEC experiments.

- Pulsed operation will potentially raise the fusion rate still further.

- We have plans to extract ions which have developed non-ideal orbits at low energy, thus substantially increasing the energy confinement time and further raising efficiency.

Good luck, guys. (Hat tip: jumartinez at talk-polywell.org.)

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