dkirtley

Sam Cohen’s Rotating Magnetic Field experiments have shown higher temperature and reasonably long-lived FRCs. His vision is steady operating, 3He systems, atleast at first targeting propulsion. As you dial up the Helium percentages, the neutron output goes down, though the required ion temperature goes up. Princeton Satellite Systems has several NASA programs looking at the propulsion applications.

1% of all deserts is only correct if you are talking about only today's electricity use. Even moderate growth and actually solving energy, not just the electricity subset drives these percentages much higher. To get US centric again, NREL published an optimistic 2016 report suggesting that the maximum rooftop solar capability could ever meet is 40% of electricity. That's 15% of today's energy use in an electricity heavy country.

6% is about the best we can do with a closed cycle. Extra-terrestrial sources could push those numbers even lower by running up to a pure D-He3 reaction.

Thanks FiatLuxDave, I think you are exactly right. Prototype/design cycle time is a huge issue with fusion, fission, and many other energy technologies. No matter how good your idea may be, you have to be able to build, test, iterate, prove, and commercialize it quickly (and ideally, cheaply, but I would argue quickly is even more important). In energy, the physics make everything work better at large scale so it is easy to fall into the "build it bigger" trap.

Interesting: ... "scientific research can provide some measure of confidence that short-term, acute exposures up to about 1-2 T [1000-2000 milliT] should be safe... However, it is not possible to determine whether there are any long-term health consequences even from exposure in the milliT range because, to date, there are no well-conducted epidemiological studies with sufficient power to be able to come to any conclusion on this, and there are no good long-term animal studies."

http://www1.mcw.edu/radiationoncology/ourdepartment/radiatio...

This actually a huge issue for space travel, all of the random electronics and possibly magnetic radiation shielding may be serious. http://www.nasa.gov/directorates/spacetech/niac/westover_rad...

3 Tesla Magnetic field MRI's are now common and I have heard rumors of up to 7T machines in the works: http://www.healthdiagnostics.com/svc_hi_field.php

Helion here. There are pretty big differences. They did get the high Beta and compact/modular parts right. The primary differences are that Helion operates entirely pulsed with simple non-superconducting magnets. That allows us to go to higher temperatures, cleaner fuels, directly recovery energy, and if everything works as planned should eliminate the wall concerns and need for particle beams.

I do think what they are doing is interesting. If its like the Gas Dynamic Trap or Tandem Mirror it has promise, atleast from the fundamental physics point of view. Researchers in Novosibirsk had encouraging results in the last 5 years. They still have a long road ahead to get to fusion-relevant temperatures, but we are staying tuned to this one.

This looks very similar to the old Russian Gas Dynamic Trap: https://e-reports-ext.llnl.gov/pdf/366958.pdf

RF and neutral beam heated steady reactor with very high mirror ratio and superconductors.

The best way to make Helium 3 is with Deuterium fusion. Its a very interesting bootstrap question -- how do you build new reactors, if you have to have working reactors to generate fuel?

Not yet, right now we are focused on pushing the technical milestones as fast as possible. This is a great question, what do people here think about a crowdfunding campaign for something like fusion, is it worth it?

Great reply. The wiki also has a long discussion about Helium 3. http://en.wikipedia.org/wiki/Helium-3 Fusion produces neutrons either in the first or secondary reactions, but there are ways to minimize the amount of them and their energy (and damage/radioactivity)to where you don't generate "nuclear waste". There is an interesting continuum of fusion reactions from pure D-D (which produces little energy, but lots of lower energy neutrons) to D-He3 (that produces some neutrons and lots of energy) to pure He3-He3 (that is called 'anuetronic').

D-D fusion makes Tritium (that decays into He3), Helium 3, or Helium 4 through the fusion process itself, with no breeding.

We believe that there is a correct ratio called Self-Supplied in which you have a small amount of 2.4 MeV neutrons, only deuterium as an input fuel, and the majority of the energy is from the Helium 3 fusion. The hard part is how to separate out the right isotope mixture from the exhaust between pulses.

Yes! Prof. John Slough is the Chief Scientist at Helion and the inventor of the Fusion Engine. UW has been leading the field of 'alternates' fusion for decades. Our 'About Us' page has a short blurb: http://www.helionenergy.com/

There was another good one in science. http://news.sciencemag.org/physics/2014/07/fusions-restless-...

We are hiring for Redmond, WA, but only people that are excited and forward! Our Contact page http://www.helionenergy.com/ has the link.

Both GF and us (Helion) are attempting to dramatically shrink the size and cost of fusion reactors. We are doing that by compressing a fusion plasma repeatedly to generate energy, rather than trying to heat and confine it for long periods. The main difference is that Helion uses high field pulsed magnets to compress the plasma, GF uses pistons to generate liquid metal shocks.

We are hoping three years, three decades is just too late to matter. Part of what was not mentioned are the years that we have put into this already. Fusion is definitely a tough problem, but one that is worth it to solve.