3 ms·

> Our analysis indicates that better than break-even performance is possible even in a deuterium-deuterium system at bench-top scales. That means it should be

> Our analysis indicates that better than break-even performance is possible even in a deuterium-deuterium system at bench-top scales. That means it should be relatively easy to verify in a laboratory, right?

ChuckMcM 7y ago
Yes, that was my take on the paper.
ceejayoz 7y ago
That it hasn't since publication in 2015 indicates they missed something.
- rolph 7y ago
  https://arxiv.org/abs/1808.00622 https://arxiv.org/abs/1808.00622 [2019] " Equations describing plasma equilibria are derived from the total energy of the system. The MHD equilibrium is shown to hold even for systems where the magnetic field may locally vanish. Through conservation of helicity, confinement is shown to be intimately related to electromagnetic tension. For an axisymmetric device, the presence of a magnetic field or current circling the axis is shown to be destabilising. This provides a simple explanation for the poor performance of some devices for which MHD predicts stability" there is a cadence between electric charge motion and magnetic flux, and a dynamic balance has to be manufactured. the addendum describes the magnetic confinement of electrodes to be a source of instability in the reaction. as well as providing a corrective factor for the mathematics, describing the theory.
Retric 7y ago
Fusion over breakeven releases a boatload of ionizing radiation. So, it’s not exactly a safe thing to put on a lab bench. As even a single watt of power requires the kind of wall you put on a nuclear power plant. As a rule of thumb, fusion is only really vastly better than fission once you turn it off. That said, I agree there is likely something wrong with the design.
- rolph 7y ago
  Thats the thing, even if you get the technique down right, then the system has to be engineered to transduce that energy and other product into something we can use. such as mechanical motion or electromagnetic generation/propulsion, or harvesting products such as isotopic helium.
- gpderetta 7y ago
  you can build your own fusion reaction in the comfort of your home. Apparently fusor devices [1] are hobbist level difficulty. They are nowhere near break even, but they do generate a lot of radiation which can still be contained safely on a benchtop apparently. [1] https://en.wikipedia.org/wiki/Fusor https://en.wikipedia.org/wiki/Fusor
  - Retric 7y ago
    At the hobbyist level they are making detectable amounts of radiation, but only something like 1 trillionth of a watt worth of fast neutrons per second.
    - gpderetta 7y ago
      Right, I completely missed the point that you were concerned about the amount of radiation at break even. I wonder whether you could detect the increased efficiency well before reaching break even (that wouldn't prove that you can reach break even of course)?
      - Retric 7y ago
        Starting with HH vs DD fusion gives you validation with orders of magnitude less radiation, lower pressures would be similarly useful. But, IMO partnering with someone in the nuclear industry is probably the best bet. Really, if your not asking for money just a location that's a fairly easy sell. If it doesn't work at all that's no real cost to them. If it almost works that's a cheap neutron source that's easy to turn on and off which is valuable. And if it actually works that's one of those world changing things people are willing to support.

ChuckMcM 7y ago

Yes, that was my take on the paper.

ceejayoz 7y ago

That it hasn't since publication in 2015 indicates they missed something.

rolph 7y ago
https://arxiv.org/abs/1808.00622 https://arxiv.org/abs/1808.00622 [2019] " Equations describing plasma equilibria are derived from the total energy of the system. The MHD equilibrium is shown to hold even for systems where the magnetic field may locally vanish. Through conservation of helicity, confinement is shown to be intimately related to electromagnetic tension. For an axisymmetric device, the presence of a magnetic field or current circling the axis is shown to be destabilising. This provides a simple explanation for the poor performance of some devices for which MHD predicts stability" there is a cadence between electric charge motion and magnetic flux, and a dynamic balance has to be manufactured. the addendum describes the magnetic confinement of electrodes to be a source of instability in the reaction. as well as providing a corrective factor for the mathematics, describing the theory.

Retric 7y ago

Fusion over breakeven releases a boatload of ionizing radiation. So, it’s not exactly a safe thing to put on a lab bench. As even a single watt of power requires the kind of wall you put on a nuclear power plant. As a rule of thumb, fusion is only really vastly better than fission once you turn it off. That said, I agree there is likely something wrong with the design.

rolph 7y ago
Thats the thing, even if you get the technique down right, then the system has to be engineered to transduce that energy and other product into something we can use. such as mechanical motion or electromagnetic generation/propulsion, or harvesting products such as isotopic helium.
gpderetta 7y ago
you can build your own fusion reaction in the comfort of your home. Apparently fusor devices [1] are hobbist level difficulty. They are nowhere near break even, but they do generate a lot of radiation which can still be contained safely on a benchtop apparently. [1] https://en.wikipedia.org/wiki/Fusor https://en.wikipedia.org/wiki/Fusor
- Retric 7y ago
  At the hobbyist level they are making detectable amounts of radiation, but only something like 1 trillionth of a watt worth of fast neutrons per second.
  - gpderetta 7y ago
    Right, I completely missed the point that you were concerned about the amount of radiation at break even. I wonder whether you could detect the increased efficiency well before reaching break even (that wouldn't prove that you can reach break even of course)?
    - Retric 7y ago
      Starting with HH vs DD fusion gives you validation with orders of magnitude less radiation, lower pressures would be similarly useful. But, IMO partnering with someone in the nuclear industry is probably the best bet. Really, if your not asking for money just a location that's a fairly easy sell. If it doesn't work at all that's no real cost to them. If it almost works that's a cheap neutron source that's easy to turn on and off which is valuable. And if it actually works that's one of those world changing things people are willing to support.