4 ms·

MHD have pretty low efficiency (otherwise the world wouldn't have bothered with turbines, pistons/crankshafts, etc.). They claim 95% recovery. That is amazing.

by trhway 4y ago

MHD have pretty low efficiency (otherwise the world wouldn't have bothered with turbines, pistons/crankshafts, etc.). They claim 95% recovery. That is amazing. That would in particular seem to imply that the radiative/thermal losses less than 5%, which is very strange (classic thermal radiative power is 4th power of temperature and add bremsstrahlung to that). You'd usually need high density (or size sometimes can do for it) for the radiation/thermal to not escape much. They seem to have demonstrated efficient recovery at conditions far from the real fusion where such radiative losses would be expected to grow disproportionally.

Animats 4y ago
According to Wikipedia, there's an inherent limit on MHD generators due to plasma instability. That's also the problem with most fusion systems, where everybody struggles to maintain a stable plasma for seconds. The idea behind this Helion thing seems to be to run in pulsed mode, so long term stability isn't required. Pulsed fusion systems have been around for a while. There's another startup, First Light Fusion, also claiming to have a commercial energy source Real Soon Now.[1] People have been claiming that for pulsed fusion since at least 1971, when laser confinement was a big thing. [1] https://firstlightfusion.com/ https://firstlightfusion.com/
- trhway 4y ago
  I personally believe that the pulsed/inertial would be the fusion, be it energy generation or space engine (after all the only net positive artificial fusion device so far - thermonuclear bomb - is "pulsed", and so we have only a matter of engineering to scale it down :). My bet though would be on something like Sandia Z-machine or on laser (as we've had remarkable laser efficiency improvements) as they clearly create fusion conditions (and much closer to the bomb confinement wise) and burn significant amounts of fuel (thus allowing for typical established ways of energy generation) than for example Helion where the plasma clouds don't carry much fuel and thus can't produce significant amounts of energy.

by trhway 4y ago

Animats 4y ago

According to Wikipedia, there's an inherent limit on MHD generators due to plasma instability. That's also the problem with most fusion systems, where everybody struggles to maintain a stable plasma for seconds. The idea behind this Helion thing seems to be to run in pulsed mode, so long term stability isn't required. Pulsed fusion systems have been around for a while. There's another startup, First Light Fusion, also claiming to have a commercial energy source Real Soon Now.[1] People have been claiming that for pulsed fusion since at least 1971, when laser confinement was a big thing. [1] https://firstlightfusion.com/ https://firstlightfusion.com/

trhway 4y ago
I personally believe that the pulsed/inertial would be the fusion, be it energy generation or space engine (after all the only net positive artificial fusion device so far - thermonuclear bomb - is "pulsed", and so we have only a matter of engineering to scale it down :). My bet though would be on something like Sandia Z-machine or on laser (as we've had remarkable laser efficiency improvements) as they clearly create fusion conditions (and much closer to the bomb confinement wise) and burn significant amounts of fuel (thus allowing for typical established ways of energy generation) than for example Helion where the plasma clouds don't carry much fuel and thus can't produce significant amounts of energy.