ITER and all things fusion.

[Nuke]

9 hours ago, SargeRho said:

Thoughts on Helion Energy? Apparently they're building a larger scale demonstration reactor, and are going for direct conversion/D-He3 fusion.
http://www.helionenergy.com/?page_id=199

I don't know enough about Fusion to judge how likely they are to succeed, though several big names have invested in them.

they have a pretty web page but thats all ive seen. i need to see more technical information to tell if its a good idea or not.

5 hours ago, Elthy said:

Helium-3 fusion wont happen. Its simply to rare, and a reactor able to fuse He3-De could also do De-De, which is way, way easier to get.

it will happen, just not on earth. use whatever fuel is abundant locally. on earth we got lots of boron and hydrogen for p-b11, and lots of deuterium for boring fusion. on the moon, he3 is easier to find (and i wonder if you cant actually farm the stuff, set up favorable conditions for natural formation on the lunar surface and other bodies). of course it will be used there and its probibly not feasible to ship it home. unless of course we become planet locked with no means off due to declining resources, failing economies and dying populations.

6 hours ago, PB666 said:

Direct energy has an amperage problem, don't see this as going any were unless neutron absorbtion creates a cascade photoelectric effect. Not likely and the electrons do not have the voltage as seen in the generators of a steam turbine. You have essentially three choices, single loop steam turbine, two loop presuurized liquid sodium(98'C) or liquid lithium (180'C) in which the steam reactor is the second stage. If you place lithium as the first loop you can breed fuels, but you have to extract the fission products during operation, the operating temperature will be higher which can cause problems for superconductors and increase the rate of part wear, and increase the cost of parts. 

direct conversion is used in reactions that produce charged paricles and no neutrons (i suppose you could use it on d-t fusion since it puts out a proton, but you still have neutrons to contend with so its easier to have a pure thermo system rather than a direct conversion and thermo hybrid system). p-b11 only puts out alpha particles and you can directly convert those in their entirety, and you then only have to contend with waste heat from running your system.

[PB666]

3 hours ago, Nuke said:

they have a pretty web page but thats all ive seen. i need to see more technical information to tell if its a good idea or not.

it will happen, just not on earth. use whatever fuel is abundant locally. on earth we got lots of boron and hydrogen for p-b11, and lots of deuterium for boring fusion. on the moon, he3 is easier to find (and i wonder if you cant actually farm the stuff, set up favorable conditions for natural formation on the lunar surface and other bodies). of course it will be used there and its probibly not feasible to ship it home. unless of course we become planet locked with no means off due to declining resources, failing economies and dying populations.

direct conversion is used in reactions that produce charged paricles and no neutrons (i suppose you could use it on d-t fusion since it puts out a proton, but you still have neutrons to contend with so its easier to have a pure thermo system rather than a direct conversion and thermo hybrid system). p-b11 only puts out alpha particles and you can directly convert those in their entirety, and you then only have to contend with waste heat from running your system.

Have you actually calculated peak amperage out put. the particles output is generally associated with a photon, often in the gamma spectrum, absorption energies also include, in simplistic terms, the heat of moving particles. All of this eventually ends up as radiative and convectional heat that ends up as the phase coversion of water. This then goes into a turbine in which a preset rotation results in the specified amperage and voltage, more amprage. Amps and volts produce are run onto a stepup transformer that essentially trades amps for volts for efficient transmission. 

[Nuke]

direct conversion doesnt use photons, it uses alpha particles (or anything with a charge for that matter). they are ejected from the core at high energy levels. you "decelerate" them by allowing them to pick up an electron. this creates a very high negative voltage on the direct conversion grid. then you just have to buck it down to line voltage (which will raise the amperage significantly) and run it through an inverter. expect about 10% loss in collection, buck and inversion and you get about 70% efficiency out of it (compared to about 42% with a rakine cycle, not counting losses at heat exchangers). 

Edited December 12, 2015 by Nuke

[SargeRho]

I did find a picture of 3 reactor prototypes, from 2008, 2010 and 2013.

[Nuke]

now thats some serious fusion pr0n. all the glowey bits <3

[PB666]

3 hours ago, Nuke said:

direct conversion doesnt use photons, it uses alpha particles (or anything with a charge for that matter). they are ejected from the core at high energy levels. you "decelerate" them by allowing them to pick up an electron. this creates a very high negative voltage on the direct conversion grid. then you just have to buck it down to line voltage (which will raise the amperage significantly) and run it through an inverter. expect about 10% loss in collection, buck and inversion and you get about 70% efficiency out of it (compared to about 42% with a rakine cycle, not counting losses at heat exchangers). 

So what is this mysterious high voltage? And above 110,000 volts circuit isolation, including in transformers becomes a big expensive problem. 

[Nuke]

100kv sounds about right (at least thats what my google fu tells me). i imagine power utilities know how to deal with dc to transmission level ac conversion. large scale pv solar does it, but at a smaller scale. expensive, yes, but its nothing we havent done before.

turns out transformers are slightly more efficient than buck regulators, and both have efficiencies in the 90-99% range. its the power inverter thats going to drop it most. still way better than rakine though.

hardest part is getting the reactor to work, and if we can do that it really doesnt matter how we get the energy out of it.

Edited December 13, 2015 by Nuke

[Stoney3K]

I believe Polywell wanted to do direct conversion but that implies voltages in the MV range (with fusion product particles having several hundred keV of energy, add a few electrons and you get hundreds of kV), and material breakdown for insulation is going to be one of the challenging factors there. Semiconductors are out of the question so there's a good chance vacuum tubes are making a comeback in that area.

IMO, ITER is never going to burn any other fuel than money. It's an academic research project, not a commercial engineering effort, so they have no interest in finishing the project on schedule, on the contrary, finishing on schedule means a lot of academics are now out of a job and looking for new research grants.

[SargeRho]

Actually, finishing ITER successfully would mean even More money even sooner, since the plan is to build DEMO after ITER has demonstrated that Tokamaks are viable power plants.

[Stoney3K]

12 minutes ago, SargeRho said:

Actually, finishing ITER successfully would mean even More money even sooner, since the plan is to build DEMO after ITER has demonstrated that Tokamaks are viable power plants.

Don't forget that from the original schedule, ITER would have already been operational by now and the groundwork for DEMO was to be laid. Instead, largely due to politics, ITER hasn't achieved first plasma yet.

The issue isn't engineering here, it's bureaucracy because it's an international, academic effort. Right now there is no commercial incentive to make nuclear fusion work on a short term scale (apparently not even global warming can convince them). They're blowing a lot of smoke on how awesome the project will be and how it will be the first project that ever achieves net power, only to dump it in a huge heat sink next to the plant because they won't hook it up to the grid. We're still *another* half of a century away from that if it is up to the ITER road map.

Also, anything that takes $15-20bn to engineer as a one-off and then another few *billion* and a quarter of a century to build doesn't really qualify as a viable power plant, when cheaper and more straight-forward alternatives are available. It would be an economical option if such a plant means that power becomes essentially limitless. ITER is not, it does not have a continuous, full load duty cycle.

Jet engines and nuclear power stations were developed in a record-setting pace for a very, very simple reason that gave them incentive to exist: The Second World War. Anything beyond that up to today's technology is only an evolution of that.

Edited December 13, 2015 by Stoney3K

[sgt_flyer]

 

48 minutes ago, Stoney3K said:

Don't forget that from the original schedule, ITER would have already been operational by now and the groundwork for DEMO was to be laid. Instead, largely due to politics, ITER hasn't achieved first plasma yet.

The issue isn't engineering here, it's bureaucracy because it's an international, academic effort. Right now there is no commercial incentive to make nuclear fusion work on a short term scale (apparently not even global warming can convince them). They're blowing a lot of smoke on how awesome the project will be and how it will be the first project that ever achieves net power, only to dump it in a huge heat sink next to the plant because they won't hook it up to the grid. We're still *another* half of a century away from that if it is up to the ITER road map.

Also, anything that takes $15-20bn to engineer as a one-off and then another few *billion* and a quarter of a century to build doesn't really qualify as a viable power plant, when cheaper and more straight-forward alternatives are available. It would be an economical option if such a plant means that power becomes essentially limitless. ITER is not, it does not have a continuous, full load duty cycle.

Jet engines and nuclear power stations were developed in a record-setting pace for a very, very simple reason that gave them incentive to exist: The Second World War. Anything beyond that up to today's technology is only an evolution of that.

 At least, now that diplomats from a lot of countries have unanimously agreed at the COP21 that something should be done to limit global warming, (even if the treaty is very vague on the how, who and when) we should start seeing a renewed interest towards clean baseload energies - fission and fusion still come to mind in this case (especially given the timeframe of until the end of the century).

now, tokamaks or other equivalent fusion technologies would be considered much safer to distribute to develloping countries than giving them fission power plants (and more than that, guess several countries would be scared to see the uranium enriching equipments needed to prepare the fuel rods used to make weapons - as seen with the problem over iran's civil nuclear program)

So - maybe a chance for more push / funding and less bureaucratic stupidity for these technologies now that climate is a concern

 

[Nuke]

even if iter-demo works, its still not really economically viable in anywhere but the richest nations on the planet. polywells are nice because you could roll them out in a factory and ship them all over the place, and its not the only option out there for an economically viable reactor.

Edited December 14, 2015 by Nuke

[Stoney3K]

10 hours ago, sgt_flyer said:

 

 At least, now that diplomats from a lot of countries have unanimously agreed at the COP21 that something should be done to limit global warming, (even if the treaty is very vague on the how, who and when) we should start seeing a renewed interest towards clean baseload energies - fission and fusion still come to mind in this case (especially given the timeframe of until the end of the century).

now, tokamaks or other equivalent fusion technologies would be considered much safer to distribute to develloping countries than giving them fission power plants (and more than that, guess several countries would be scared to see the uranium enriching equipments needed to prepare the fuel rods used to make weapons - as seen with the problem over iran's civil nuclear program)

So - maybe a chance for more push / funding and less bureaucratic stupidity for these technologies now that climate is a concern

 

I can see thorium-based breedere reactors fill in the gap in the short term. Remember that 2050, which would be the date that DEMO comes on-line in the grid, is way beyond the lifespan of all of the current politicians that signed the treaty today. So they could basically care less, the only people who would be affected are their grand-children. And I have yet to meet the first politician who is interested in making political decisions that affect his grandchildren, only to be voted out of office by the next election.

[PB666]

16 hours ago, Stoney3K said:

I believe Polywell wanted to do direct conversion but that implies voltages in the MV range (with fusion product particles having several hundred keV of energy, add a few electrons and you get hundreds of kV), and material breakdown for insulation is going to be one of the challenging factors there. Semiconductors are out of the question so there's a good chance vacuum tubes are making a comeback in that area.

IMO, ITER is never going to burn any other fuel than money. It's an academic research project, not a commercial engineering effort, so they have no interest in finishing the project on schedule, on the contrary, finishing on schedule means a lot of academics are now out of a job and looking for new research grants.

no, i think you are wrong, maybe for the material/engineering scientist. The rest of the nuclear physics nuclear chemistry scientist are waiting for the optimization testing and results tonstart coming in sonthey can write papers. For a publishing scientist these delays are a death trap. 

[Bill Phil]

The way I see it, there are two problems with fusion power: confinement time and waste disposal.

The reactors are turned on and very quickly turn off. If they stayed on, and the confinement could be made sustainablem, then we could very we'll have useful reactors.

Waste disposal would then be a problem. If we're fusing hydrogen, we'll be creating other atoms that can then get in the way. Unless it can fuse those atoms, too.

[Elthy]

Getting the Helium out of the plasma is not that hard. Its still ionised, so the magnetic fields could be arranged in a way that those heavy helium cores cant stay in it. They are tossed against a actively cooled plate, where they are pumped away by vacuum pumps.

[Bill Phil]

36 minutes ago, Elthy said:

Getting the Helium out of the plasma is not that hard. Its still ionised, so the magnetic fields could be arranged in a way that those heavy helium cores cant stay in it. They are tossed against a actively cooled plate, where they are pumped away by vacuum pumps.

But can you guarentee that it won't remove much of the main fuel?

And it's not just helium. Other products are possible, and other fusion types are possible.

[Elthy]

Such a mechanism works with the difference in weight and charge of the elements involved in the reaction. Since products are allways heavier than educts that works no matter which elements you use.

[sgt_flyer]

1 hour ago, Bill Phil said:

The way I see it, there are two problems with fusion power: confinement time and waste disposal.

The reactors are turned on and very quickly turn off. If they stayed on, and the confinement could be made sustainablem, then we could very we'll have useful reactors.

Waste disposal would then be a problem. If we're fusing hydrogen, we'll be creating other atoms that can then get in the way. Unless it can fuse those atoms, too.

Well, i guess that's why fusion scientists wait for ITER  with it, we could experiment with different methods to adress these problems  (and not only theorize - theory alone won't get you very far  :))

even if ITER doesn't work as they want, it will still allow us to learn what doesn't work  (which would be as much valuable for scientists)

[Bill Phil]

53 minutes ago, Elthy said:

Such a mechanism works with the difference in weight and charge of the elements involved in the reaction. Since products are allways heavier than educts that works no matter which elements you use.

It still has to be built.

32 minutes ago, sgt_flyer said:

Well, i guess that's why fusion scientists wait for ITER  with it, we could experiment with different methods to adress these problems  (and not only theorize - theory alone won't get you very far  :))

even if ITER doesn't work as they want, it will still allow us to learn what doesn't work  (which would be as much valuable for scientists)

Yeah, ITER might just work out. But the sad thing is that it's essentially a giant proof of concept.

[PB666]

2 hours ago, sgt_flyer said:

Well, i guess that's why fusion scientists wait for ITER  with it, we could experiment with different methods to adress these problems  (and not only theorize - theory alone won't get you very far  :))

even if ITER doesn't work as they want, it will still allow us to learn what doesn't work  (which would be as much valuable for scientists)

Thats right, if i am not mistaken the laser/rf generators are tuned to the wobble and excitation frequencies of dueterium and tritium. This means that other elements will tend to escape the plasma beam more rapidly, of course this is a vacuum and they will be in 4000+ kelvin range, but since it is helium it would prolly steal an electron from the metal housing, impart energy, and could be differentially evacuated. 

So there is a systemic out-selection of non-reactants, these reactants could be pick up by inertial particle diverters along the plane of the torroid, and cooled, generating power while condensing them, rf could be used to direct helium into a concentrated stream that is picked up at 5 microns and pressurized to 10,000 PSI while cooling in a prefilter HP (.0001to 0.000001 m) line in which it is further cooled to the gas liquid transition point for contaminating gases (litium, oxygen, nitrogen, argon, carbon dioxide, water), followed by heliums sublimation point, the remiaing gases can then be reinjected after warming, since they are already presuurized the heating.

Another option is to use a gas centrifuge, a third option is to use rf to crudely separate the helium and hydrogen isotopes and just feeding the hydrogen back to the torroid, sell the helium and let the buyer/waste disposal folks worry about separation.

A forth option is to allow the hydrogen to react with platinum. 

A fifth option is to convert hydrogen to water, introducing oxygen to the helium, but which is much more easily removed under pressure. Along this line we also have bromine gas which forms HBr which at stp can be preciptated in any common lab ultralow freezer. 

A sixth option is to use one of elemental selenium bed made of select isotopes, lots of which have been generated in spent fuel rods to absorb many of the planar nuetrons as well as energized hyodrogen isotopes, allowing the helium to pass through and be evacuated. The neutronated resins can then be recycled removing the reactants for reuse. One of the problems has been with selenium is that is nuclear activity is relatively low, and is pretty much a contanimant in fast breeder reacter schemes. However it lacks prompt critical concerns of other isotopes, its generally not considered dangerous (the nuclear isotopes), so it does have potential in large amounts of being able to create a more massive rtg that last for years, around humans. This might be suitable for powering heating systems at remote locations like Antartica. If you are talking about fusion reactors in space this actually proves useful, for example on Mars, presumb that a colony will need a fusion reactor, the colony might use sealed isotopic selenium beds to ambiently heat greenhouses, or other buildings were you need alot of area, but the surface structures are paper thin. Such a greenhouse would have high pCO2, low pN2, lower pO2 optimized for low pressure and high growth, in order to keep the pH20 high they would need to be heated. Lighting of course would come from diodes. 

Edited December 14, 2015 by PB666

[Elthy]

You seem to forget that the amount of hydrogen and helium involved in the reaction is extremly small, in the range of grams. Such a reactor will just fill a few balloons per day, not worth collecting.

[PB666]

2 hours ago, Elthy said:

You seem to forget that the amount of hydrogen and helium involved in the reaction is extremly small, in the range of grams. Such a reactor will just fill a few balloons per day, not worth collecting.

They are talking about the potential of collecting the very rare He3. Helium-3 is generated when dueterium is bombarded with neutrons and generate tritium which can then naturally decay to helium-3 within a half-life of 12 years, maybe faster at temperatures within the fusion plasma, we actually need to get it working at full power to be certain. Its not much but if you consider for fusion to be useful the scale has to be several times that of ITER and in many places. 

[wumpus]

On 12/11/2015, 6:12:33, Elthy said:

The main problem with fusion is that it will be to late. When its read we will mostly use renewables or we are doomed anyway.

I'd really like to complain that re-processed nuclear fuel rods and fuel from breeder reactors should be considered "renewable".  Using this stuff hasn't different issues (don't let another Ken Lay control the stuff), but isn't the same doom as fossil fuels.

[magnemoe]

On 14.12.2015, 16.01.33, Bill Phil said:

It still has to be built.

Yeah, ITER might just work out. But the sad thing is that it's essentially a giant proof of concept.

Yes, its however lots of other fusion projects today, far more cheaper, more focused and mostly commercial.Main difference is that it's very unsure if they work