4 ms·

a bit of background about this tech (as understood by a non-physicist) 1. Take a big metal ball and surround it by a whole bunch of synchronized pistons 2. Fi

a bit of background about this tech (as understood by a non-physicist) 1. Take a big metal ball and surround it by a whole bunch of synchronized pistons 2. Fill said ball with molten metal 3. Fire a wave of plasma from both ends of the ball 4. Time the firing of the pistons so that the plasma and pressure wave from the pistons all meet in the center and create the conditions necessary for fusion to occur. While it isn't yet proven, if this method works it would be quite a bit simpler than the other lines of research into fusion reactors which require massive arrays of magnets to suspend plasma and exotic materials that don't exist yet. I have no idea if this is actually feasible, but it sure sounds cool!

pm90 13y ago
This makes me wonder: what are the current constraints on fusion reactors? I mean, I had heard that the problem is that the current reactors consume more energy than they produce. Is that the case or is it just not possible to get fusion in the laboratory?
- arethuza 13y ago
  It's actually pretty straightforward to create fusion: http://en.wikipedia.org/wiki/Fusor http://en.wikipedia.org/wiki/Fusor The catch is doing it in a way that actually produces a surplus of energy that isn't a bomb. NB Even with bombs, most H-bomb designs actually get more energy from fission than fusion. Edit: I wish there was some rule that said that a small percentage of mega-projects like ITER had to be used to fund competing approaches like this. http://en.wikipedia.org/wiki/ITER http://en.wikipedia.org/wiki/ITER
  - maaku 13y ago
    While we are completely off topic, for those who are interested: an H-bomb typically originates more energy from does get more energy from fission than fusion, but the fissile energy is converted into more destructive forms by the fusion reaction. Much of the destructive power of an H-bomb compared with a more conventional fission design is from the fusion reaction.
- mng2 13y ago
  You are asking a few different questions here. The biggest problem for fusion in general is probably the limited theoretical understanding of plasmas, since simulations are intractable. The biggest practical problem faced by any commercial-scale deuterium-tritium fusion plant is a lack of neutron-resistant materials. Other concepts are built around aneutronic fuels such as pB11, but given the much higher temperatures required, my personal feeling is that this is shooting for Mars when one hasn't even made it to the moon. As for whether breakeven is even possible (not counting H-bombs), we have to get a little technical. 'Breakeven' is defined as when the input power is equal to output power. However to generate net power, the fusion output power needs to be converted to electricity and fed into the reactor, which means there will be thermodynamic losses. A typical ratio quoted for net power generation, also termed 'ignition', is 1:5. ITER is shooting for 1:10. The current record holder is the JT-60 tokamak in Japan. It has achieved slightly better than breakeven, with a caveat: these are simulated numbers. You see, for safety and convenience, JT-60 does not use tritium, just deuterium, so the numbers are extrapolated from the D-D case to the D-T case. This does not strike me as a major issue since other tokamaks (JET) have run with tritium, but I am not an expert. Tokamaks are the furthest along in terms of achieving ignition, but there are still a host of practical issues that need to be solved before the technology can be commercialized. http://en.wikipedia.org/wiki/JT-60 http://en.wikipedia.org/wiki/JT-60 http://en.wikipedia.org/wiki/Lawson_criterion http://en.wikipedia.org/wiki/Lawson_criterion
modeless 13y ago
You missed a step: 2.5: Spin the liquid metal really fast to create a vortex (like in a water bottle) such that the hole in the vortex reaches all the way to the bottom of the ball. Also note that in step 3, "both ends" of the ball are the top and bottom. The plasma from the bottom is fired up through the hole in the middle of the vortex.

pm90 13y ago

This makes me wonder: what are the current constraints on fusion reactors? I mean, I had heard that the problem is that the current reactors consume more energy than they produce. Is that the case or is it just not possible to get fusion in the laboratory?

arethuza 13y ago
It's actually pretty straightforward to create fusion: http://en.wikipedia.org/wiki/Fusor http://en.wikipedia.org/wiki/Fusor The catch is doing it in a way that actually produces a surplus of energy that isn't a bomb. NB Even with bombs, most H-bomb designs actually get more energy from fission than fusion. Edit: I wish there was some rule that said that a small percentage of mega-projects like ITER had to be used to fund competing approaches like this. http://en.wikipedia.org/wiki/ITER http://en.wikipedia.org/wiki/ITER
- maaku 13y ago
  While we are completely off topic, for those who are interested: an H-bomb typically originates more energy from does get more energy from fission than fusion, but the fissile energy is converted into more destructive forms by the fusion reaction. Much of the destructive power of an H-bomb compared with a more conventional fission design is from the fusion reaction.
mng2 13y ago
You are asking a few different questions here. The biggest problem for fusion in general is probably the limited theoretical understanding of plasmas, since simulations are intractable. The biggest practical problem faced by any commercial-scale deuterium-tritium fusion plant is a lack of neutron-resistant materials. Other concepts are built around aneutronic fuels such as pB11, but given the much higher temperatures required, my personal feeling is that this is shooting for Mars when one hasn't even made it to the moon. As for whether breakeven is even possible (not counting H-bombs), we have to get a little technical. 'Breakeven' is defined as when the input power is equal to output power. However to generate net power, the fusion output power needs to be converted to electricity and fed into the reactor, which means there will be thermodynamic losses. A typical ratio quoted for net power generation, also termed 'ignition', is 1:5. ITER is shooting for 1:10. The current record holder is the JT-60 tokamak in Japan. It has achieved slightly better than breakeven, with a caveat: these are simulated numbers. You see, for safety and convenience, JT-60 does not use tritium, just deuterium, so the numbers are extrapolated from the D-D case to the D-T case. This does not strike me as a major issue since other tokamaks (JET) have run with tritium, but I am not an expert. Tokamaks are the furthest along in terms of achieving ignition, but there are still a host of practical issues that need to be solved before the technology can be commercialized. http://en.wikipedia.org/wiki/JT-60 http://en.wikipedia.org/wiki/JT-60 http://en.wikipedia.org/wiki/Lawson_criterion http://en.wikipedia.org/wiki/Lawson_criterion

modeless 13y ago

You missed a step: 2.5: Spin the liquid metal really fast to create a vortex (like in a water bottle) such that the hole in the vortex reaches all the way to the bottom of the ball. Also note that in step 3, "both ends" of the ball are the top and bottom. The plasma from the bottom is fired up through the hole in the middle of the vortex.