30 ms·
With Helion pulse design peak neuron flux luminosity will still be much higher than that was observed in nuclear reactors. Compared with tokamaks their magnets
by _0w8t 4y ago
With Helion pulse design peak neuron flux luminosity will still be much higher than that was observed in nuclear reactors. Compared with tokamaks their magnets will be directly exposed to it.
Plus their idea to convert fusion energy directly into electricity depends on many unknowns to assert that it will work with reasonable efficiency.
So even if their approach may work to produce positive energy output in few years, a practical device will still be far away.
Edit: Helion itself admits that net positive in electricity with D-3He is tricky even with their design at that presentation.
So most likely their first prototype will be D+D with all the problems associated with high-energy neutrons.
- DennisP 4y agoBear in mind that Helion's magnets will not be superconductors. Last I saw, they were looking at an aluminum alloy. Exposure to D-D neutrons isn't likely to be a structural problem at least, since you don't get the helium buildup in materials that you get with D-T. The presentation says they think they can get a 5X gain with D-3He, and they think that's sufficient given the efficiencies of their heating and extraction.
- _0w8t 4y agoThe new video by the same guy https://youtube.com/live/wK5v1Nw98xs https://youtube.com/live/wK5v1Nw98xs from 32 min describes how Helion will get a lot of D+T neutrons from the secondary reactions despite all their efforts. Even without that the neutron flux from D+D reaction by Helion own admission will be enough to do a lot of damage within days of operation based on experience with slower fission neutrons.
- smaddox 4y agoHelion as already demonstrated recovering 95% of the energy from non-fusable plasmas and Q << 1 plasmas. Thousands of times. It's perhaps worth noting that the high speed, high power electronics required to implement their approach are fairly new. I don't know how old the concept of FRC merging is, but if it existed in the 70's they wouldn't have had the technology to build it. Edit: and to be clear, I'm talking about the dynamic control circuits, not the capacitors. That's old technology.
- _0w8t 4y agoThe new video by the same guy who created the original criticism https://youtube.com/live/wK5v1Nw98xs https://youtube.com/live/wK5v1Nw98xs starting from 2:03:00 explains that 95% recovery efficiency is not the whole story.
- deleted 4y ago[deleted]
- smaddox 4y agoIon escape might be a significant consideration, but given the plasma density and magnetic field strength, I'm guessing it wouldn't degrade the efficiency too much. Presumably they've done the calculations. I have not. As for the input heating loss, presumably that's included in the 95% recovery figure. If it's not, then it would definitely be good to know what the actual figure is including input heating losses.
- DennisP 4y agoThe nice thing about colliding two FRCs is that they form a new FRC with all their kinetic energy converted to heat, and it's very efficient to accelerate an FRC.