What Source of Power in the Future?

[Durandal]

well, that puts the Farnsworth-Hirsch Fusor a whole lot closer to success in my book, as amateurs are actually doing fusion to the same level as the multi-billion $ tokamak and Inertial Confinement guys, yet can do so in their own home workshops for the cost of a used car.

Indeed, and you can create a complex, unpredictable (chaotic) system with about $10 and a trip to Sears. Most people don't realize that scientists love the simple experiments much better than the ones involving multi-billion dollar equipment. :D

right now, the best funded Fusor work is being done at the U of Illinois, and they ARE getting neutron counts -- using straight De+De -- in the same vicinity as most tokamaks, yet still are spending a lot less money to do it (fusors are managing to keep pace with the neut counts of tokamaks regardless of fuel, and can easily run on De+Tritium, but tritium is naturally radioactive, and heavily regulated)... Georgia Tech is considering starting up work with the device as well. The main problems with Fusors have to do with preventing grid losses -- fusors work using electrostatic forces, with 2 grids usually arranged as an inner and outer sphere. ions are accelerated by the electrostatic forces thru the gaps in the grids, but once E levels get high enough, they (the ions) start hitting the grids, heating them up and eventually causing material failure. These losses also are the principal cause of failure to run at the charge levels necessary to get anywhere near a self-sustaining reaction. If somebody manages to figure out a way to minimize or eliminate the grid losses, the fusor has it made. The Holy Grail however is to use aneutronic fuels in the fusor -- no neutrons, no waste products, no gradually turning the containment vessel radioactive... just charged particles that can be harvested for direct electricity, without need for turbines, thermocouples etc.

That's the biggest problem with nuclear fusion: it needs a shitload of pressure. The only practical solution has been to construct a plasma within a magnetic container (any material would simply vaporize under the required temperatures) in such a manner that the probabilities of ion collision would be high enough to permit useful fusion to take place. Granted, there is laser-pellet induced fusion, but from what I've heard, the plasma solution is more promising.

From how I understand it, fusion is just another way of turning the turbine. It releases much more energy, so it can turn the turbine longer, and it carries no radioactivity along with it. I was unaware that they would just harvest charged particles, and I almost doubt that's the case because the useful work in a fusion process would come from the photon release, which would heat up the reactant water, which would turn the turbine and stuff. Unless you mean using the outburst of photons to ionize atoms, of course.

[Shaka[Zulu]]

man... snipping myself is painful...

Indeed, and you can create a complex, unpredictable (chaotic) system with about $10 and a trip to Sears. Most people don't realize that scientists love the simple experiments much better than the ones involving multi-billion dollar equipment.

so true... this is an example of a fusor built by an undergrad college student! (when I build my 1st I hope to do as well)

That's the biggest problem with nuclear fusion: it needs a shitload of pressure. The only practical solution has been to construct a plasma within a magnetic container (any material would simply vaporize under the required temperatures) in such a manner that the probabilities of ion collision would be high enough to permit useful fusion to take place. Granted, there is laser-pellet induced fusion, but from what I've heard, the plasma solution is more promising.

actually, this is one of the strongest points in favor of the fusor design -- there are no magnetic fields, with their attendant weaknesses (polarity, geometry etc.) -- in every magnetically confined system, plasma eventually leaks out of the field and impacts the container, dumping a shitload of power into the magnets, and heating them past their superconducting limits -- once in the mid-80's the princeton tokamak suffered a breach that dumped so much juice into the magnets that the entire 200-ton vessel was lifted 4 inches off the floor! to date, there is no magnetic confinement device capable of operating durations comparable to fusors, which can operate in a steady (but not self-sustaining) fusion mode for tens of minutes or more, depending on the design. in fusors, it is almost unheard of for the plasma to impact the container (if it does, it means something is seriously wrong... bad grid, bad vacuum etc) -- if you ever see one in 'star' mode you will see what I mean. here is an example:

From how I understand it, fusion is just another way of turning the turbine. It releases much more energy, so it can turn the turbine longer, and it carries no radioactivity along with it. I was unaware that they would just harvest charged particles, and I almost doubt that's the case because the useful work in a fusion process would come from the photon release, which would heat up the reactant water, which would turn the turbine and stuff. Unless you mean using the outburst of photons to ionize atoms, of course.

true for neutronic reactions, which heat water similarly to fission reactors... aneutronic fuels effectively sidestep the issue as they produce protons, electrons and heavier charged particles almost exclusively (x-rays too iirc). there is still a need for coolant, but not as a power conversion step. I can look up some common reactions if you like, and maybe provide some better details on fusor design.