A hydrogen bomb surpasses break even. It just isn’t harnessable.


Bob

Actually it's the energy of the fission products that drives the reaction. Which is to say that fusion alone is simply not capable of any sort of sustained chain reaction.

A good analogue is the "water-powered" automobile concept. Supporters claim that it would run by using water itself as a fuel. What they fail to mention is that a constant voltage is required to first separate the oxygen from the hydrogen before combustion is even possible. And of course it just so happens that the energy required to achieve that will always be MORE than that engine could possibly generate. Why? Well because water is literally BURNED (ie: oxidized) hydrogen! It has to be UNBURNED before it can be used as a fuel. There are really no other options. (Whereas ACTUAL fuels contain energy "locked up" in the bonds which can then be easily liberated by kicking of the reaction with a simple spark in the presence of an oxidizer.)

Well the same basically goes for fusion. You could throw 1.21 Gigawatts at it and STILL wouldn't even come close to quenching its thirst! Fission on the other hand locks up energy in the form of a quite different kind of bond but the effect is in fact much the same as with ordinary fuels. Small energy input with high output. It's no wonder there is such a high demand for new nuclear reactors. Unlike fusion the output obtained is basically "free".

 

There have been tests now that show that quantum computing works, at least for some things.

One really good example is using quantum computing to explore the world of the quanta. If not anything else, it uncovers some of the mysteries of the quantum world.


But what is most interesting to me is a lot of what we see here has to be accepted as new physics possibly without any explanation as of yet. Apparently we can measure things now that we cant completely explain using any kind of classical mechanical model because no model like that can exist, even though the phenomenon is real. The world of the tiny is a different world detached from what we normally call reality, and that makes it even more difficult to predict what might come in the future.

But what could be better for exploring the quantum world than a machine that actually works in the quantum world, or at least depends on the physics of the quantum world to operate.


Last i read, China had achieved the fastest quantum computer so far.

Bear in mind no one ever provably built an actual quantum computer. And the simple reason for that is that the very working principles which have been proposed for such a machine are AT THE VERY CORE inherently flawed. The actual intent of the Schrödinger thought experiment was to clear up the insanity of claims that everything in the universe is in superposition of all possible states. Unfortunately many chose to instead run with the idea for whatever reason and as a result most people merely assume it to be true. But it isn't. Wave functions don't "collapse" upon "measurement".

YES the thing you are observing is most certainly to one degree or another governed by a probability density function. That nevertheless DOES NOT mean that the object itself is in some weird superposition of states just waiting around to be "observed" by someone or something before taking on its "final" state. And THAT is why we shall never see a TRUE quantum computing system. It just isn't based on reality.

 

Actually it's the energy of the fission products that drives the reaction. Which is to say that fusion alone is simply not capable of any sort of sustained chain reaction.

What is your definition of s sustained fusion reaction, then? Certainly the stars are a sustained fusion reaction.

Bob

 

What is your definition of s sustained fusion reaction, then? Certainly the stars are a sustained fusion reaction.


Bob

Sure but only thanks to the ever-present and extreme gravitational forces involved. (Which for our sun is roughly two octillion tons of SUSTAINED pressure directed toward the center!). Nothing on Earth could possibly generate that kind of pressure/force on a continuous basis.

 

Fusion ignition like H-bombs (where fission lights the 'match') is self-sustaining Fusion until the released energy destroys the reaction plasma fuel and everything near it. We have controlled non-breakeven Fusion ignition reactions today scaled up to Megajoules of fusion energy in labs.

The hard problem is not 'Fusion', fusion is easy (demonstrated in a lab in 1934), the hard problem is 'Plasma'.

https://phys.org/news/2021-08-major-nuclear-fusion-milestone-ignition.html

While the latest experiment still required more energy in than it got out, it is the first to reach the crucial stage of 'ignition', which allowed considerably more energy to be produced than ever before, and paves the way for 'break even', where the energy in is matched by the energy out.

https://van.physics.illinois.edu/qa/listing.php?id=18653&t=self-sustaining-nuclear-fusion

Q & A: Self-Sustaining Nuclear Fusion

 

Bear in mind no one ever provably built an actual quantum computer. And the simple reason for that is that the very working principles which have been proposed for such a machine are AT THE VERY CORE inherently flawed. The actual intent of the Schrödinger thought experiment was to clear up the insanity of claims that everything in the universe is in superposition of all possible states. Unfortunately many chose to instead run with the idea for whatever reason and as a result most people merely assume it to be true. But it isn't. Wave functions don't "collapse" upon "measurement".

YES the thing you are observing is most certainly to one degree or another governed by a probability density function. That nevertheless DOES NOT mean that the object itself is in some weird superposition of states just waiting around to be "observed" by someone or something before taking on its "final" state. And THAT is why we shall never see a TRUE quantum computing system. It just isn't based on reality.

Part of what you are saying contradicts many things i have read within maybe the last year or so.

But your last statement is very interesting and maybe tugs at the heart of the matter:
"It just isn't based on reality".
The problem with that statement is that our reality as human beings is based on many many years of experience where that experience is gained by measurements we have made with our eyes, ears, etc., and processed by our brains which effectively make those measurements by averaging trillions of particles and particle movements, and so until now we never had any direct measurement of any individual particles which means until recently we had no idea what these particles were doing or how they were acting in novel situations and we didnt need to because we survived without needing that knowledge. Now that we can measure particle activity more succinctly, we find that the entire concept of 'reality' comes into question. What is reality to us simply is not reality to them (the particles). This opens up a new chapter in physics where for now we just have to accept what is happening and work with it because there aint no way to disprove it, it's been tried.

See, we have come this far as humans to understand the universe in a certain way, with certain mechanisms that we took for granted to be true. However, now that we are looking at finer details we find that some things dont actually work the way we thought at first, and why should they, they dont have to comply with what we believe are laws of the universe, instead we have to comply with whatever they are actually doing as we discover more details as time goes on. We've always done this, but in the past most of what we did was again based on statistical analysis that until now we didnt even realize was statistical in nature because we had nothing else yet that would pluck out the mechanisms of those statistical operations. In a computer, when we add 1+3 and get 4 we then usually throw out the 1 and the 3, keeping just the 4. We then cant look back to find out exactly how that 4 came to be. Was it 1+3 or was it originally 2+2 or was it 0+4 or a million million other possibilities 1.1+2.9 perhaps. Even more to the point, if we added numbers 1+2+3 and took the average and printed it out on paper and handed it to someone else, they would see the number "2" and that's all. They would never see the 1, 2, or 3, and after all it could have been a million million other numbers that led to that average of 2. So really they dont know what the details were that led to the 2 they just see that 2, and that 2 has great meaning to them because it tells them something important they wanted to know in order to perhaps run their company. So they didnt need to know the underlying details of how that 2 came to be they just needed to know that it was 2 and not 3 for example. At some point someone found that if they did know the origin of that 2 they would be able to calculate something with more precision and so they start to think about finding out what those original numbers were. Before that, their reality emerged as a simple number '2' but now their reality has to be more detailed if they want to be able to calculate more accurately and possibly even cover more cases than they could before.

But back to the issue of 'acceptance' for a minute. What if we found out that everything in the universe has existed before any big bang and actually has 'always' existed. That means that there was never a time no matter how far we go back where this stuff has never existed. It simply "always was".]
That, to us, would seem very far out and hard to grasp so we might reject it because what we have measured statistically and compiled with our brains over years and years told us that everything evolves from one thing to another, and even then we have an extremely small window of time that we have been doing this. So how could we possibly think we know what is true and what isnt, for the entire universe and possibly more and over ALL time from who knows what the starting point was or if there even was a starting point. But anyway, if there was no starting point because everything has always existed, we'd have to accept that without detailed measurement.
We have laws of thermodynamics that tell us that systems must evolve in a certain way, but just what is the system here. Is it our solar system, or the galaxy, the universe, or the universe of universes, or something even bigger.

So i guess the main point here is since we dont know everything yet basically everything is on the table yet as to what reality really is. Since we cant know that exactly just yet, we cant make statements that exclude certain attributes except under some presumed paradigm that we are stuck with having to lay out beforehand that worked for us in the past. If it comes time to change taht paradigm, we either change with it or keep our feet stuck in the mud of old science. There are just too many experiments that show that at least for now we are stuck in the mud, but we are starting to break free little by little, day by day.

 

Nothing on Earth could possibly generate that kind of pressure/force on a continuous basis.

It doesn't have to
There are numerous pulsed plasma techniques being explored to generate the ignition conditions for only a small fraction of a second, which I think will be more likely to produce break-even conditions using a much smaller reactor than the monstrous Tokamak they are building in France.

Some of these techniques also have a couple of other advantages:
One is that they can use the hydrogen-boron cycle which produces few neutrons as compared to the Tokamak's hydrogen-tritium fuel cycle that requires heavy shielding and can generate radioactive isotopes.
Another is the possibly generating electricity directly from the fusion hydrogen-boron plasma, instead of using the inefficient and costly thermal steam, mechanical turbine-generator cycle that the Tokamak and other hydrogen-tritium cycles (which are designed to generate heat), require.

 

Direct electric energy generation from fusion is mainly a marketing point for lab scale demos. We have tons of steam thermal experience in the GW range and some limited direct electrical energy conversion engineering at smaller scales.
Hell, we built direct electrical energy conversion plants using coal.
https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator

A coal-fueled MHD generator is a type of Brayton power cycle, similar to the power cycle of a combustion turbine. However, unlike the combustion turbine, there are no moving mechanical parts; the electrically conducting plasma provides the moving electrical conductor. The side walls and electrodes merely withstand the pressure within, while the anode and cathode conductors collect the electricity that is generated. All Brayton cycles are heat engines. Ideal Brayton cycles also have an ideal efficiency equal to ideal Carnot cycle efficiency. Thus, the potential for high energy efficiency from an MHD generator. All Brayton cycles have higher potential for efficiency the higher the firing temperature. While a combustion turbine is limited in maximum temperature by the strength of its air/water or steam-cooled rotating airfoils; there are no rotating parts in an open-cycle MHD generator. This upper bound in temperature limits the energy efficiency in combustion turbines. The upper bound on Brayton cycle temperature for an MHD generator is not limited, so inherently an MHD generator has a higher potential capability for energy efficiency.

Bremsstruhlung and other radiation effects will still happen with aneutronic devices. A 100MW in 1GW out Q10 aneutronic reactor even with 90% electrical energy conversion will have 200MW of heat waste to dump if you don't have some sort of thermal conversion cycle.

 

Direct electric energy generation from fusion is mainly a marketing point for lab scale demos. We have tons of steam thermal experience in the GW range and some limited direct electrical energy conversion engineering at smaller scales.
Hell, we built direct electrical energy conversion plants using coal.
https://en.wikipedia.org/wiki/Magnetohydrodynamic_generator


Bremsstruhlung and other radiation effects will still happen with aneutronic devices. A 100MW in 1GW out Q10 aneutronic reactor even with 90% electrical energy conversion will have 200MW of heat waste to dump if you don't have some sort of thermal conversion cycle.

So are you saying that fusion electrical energy generation will never become a reality?
If that was really true, then we have a lot of scientists inf countries spending money on stuff that they know will never work. Accusing them of that would require being able to prove conclusively that there is no way it can work. However, the very reason they are doing these experiments is to find out how to do it and originally it was to find out if it would work, but they moved on from trying to find out if it would work to actually producing something that works because so far it's almost definite that ti will work at some point in time. True, it may be jumping the gate, but that's the way we do things. If we see something promising we go after it and if experiments show signs of hope we put money and time into it. The payoff would be incredible. Not only do we get cleaner energy, we also get rid of the huge risk of what we get from fission. The Fukushima disaster dumped huge amounts of contaminated water into the Pacific Ocean, and some plants (flowers, etc.) 100 miles from the site are severely mutated. Getting rid of those kind of risks (and many more) would be a Godsend so it makes sense to throw a lot of effort into it.
I think current plants generate around 25GW hours of heat per day, not sure what they do with it though.

 

So are you saying that fusion electrical energy generation will never become a reality?

I wouldn't say that, but so far, the progress has been glacial. The old cliché about it always being 10 years away seems to be holding up pretty well.

Bob

 

I wouldn't say that, but so far, the progress has been glacial. The old cliché about it always being 10 years away seems to be holding up pretty well.

Bob

I understand and agree in part. There are still engineering challenges that go beyond what we normally think of, but then that is what engineering is all about. Also, ITER is not said to go online until 2035 more than 10 years from now. It will be the first reactor to reach an 'efficiency' of 1000 percent the level believed to be the minimum necessary. The smaller units only get up to 70 percent but they are all much smaller (several dozen around the world).
On the plus side, the ITER project involves many countries chipping in so that means a lot of scientists must be in on this. From what i understand, it is the larges collaborative effort in history.

Of course only time will tell. Engineering challenges i liken sort of like the development of the 'tiles' of the Space Shuttle. Better tiles would have required better materials engineering which could be the place where quantum computing comes into play.
But like many other new ideas it's the waiting game again ... waiting to see if they can get it going and dont run out of support on the way.

Oh one more little interesting thing about all this. On the way to a fully operational unit, the various engineering advances will no doubt produce products that can be used elsewhere. I am expecting high temperature products, procedures, and techniques to come out of this even if we never get a working unit. So at least we should benefit in one way or another.

 

So are you saying that fusion electrical energy generation will never become a reality?
If that was really true, then we have a lot of scientists inf countries spending money on stuff that they know will never work. Accusing them of that would require being able to prove conclusively that there is no way it can work. However, the very reason they are doing these experiments is to find out how to do it and originally it was to find out if it would work, but they moved on from trying to find out if it would work to actually producing something that works because so far it's almost definite that ti will work at some point in time. True, it may be jumping the gate, but that's the way we do things. If we see something promising we go after it and if experiments show signs of hope we put money and time into it. The payoff would be incredible. Not only do we get cleaner energy, we also get rid of the huge risk of what we get from fission. The Fukushima disaster dumped huge amounts of contaminated water into the Pacific Ocean, and some plants (flowers, etc.) 100 miles from the site are severely mutated. Getting rid of those kind of risks (and many more) would be a Godsend so it makes sense to throw a lot of effort into it.
I think current plants generate around 25GW hours of heat per day, not sure what they do with it though.

I'm pro actual and practical fusion energy, not pie in the sky, low probability, high possible return investments designed to skirt the problems with aneutronic fusion systems.
I'm saying, today, now there are zero designs and possible designs that will actually produce positive grid power for any means of fusion energy conversion to electricity in the near future, don't believe what marketing says to possible investors.

http://depts.washington.edu/physcer...ntations1210/4-Esuabana-Aneutronic Fusion.pdf
https://emagazine.com/hb11-energys-...cess-is-it-the-way-out-of-the-fusion-impasse/


Direct conversion sounds great but the history of it being actually better than thermal steam to turbines is mixed.

 

I'm pro actual and practical fusion energy, not pie in the sky, low probability, high possible return investments designed to skirt the problems with aneutronic fusion systems.
I'm saying, today, now there are zero designs and possible designs that will actually produce positive grid power for any means of fusion energy conversion to electricity in the near future, don't believe what marketing says to possible investors.

http://depts.washington.edu/physcer...ntations1210/4-Esuabana-Aneutronic Fusion.pdf
https://emagazine.com/hb11-energys-...cess-is-it-the-way-out-of-the-fusion-impasse/


Direct conversion sounds great but the history of it being actually better than thermal steam to turbines is mixed.

It sounds like you are saying, "I'll believe it when i see it", and i think we all share that sentiment to some extent, but i also find it hard to believe that so many scientists from so many different countries are basically swindlers and raconteurs. They say now that it has been proved that it works scientifically the remainder of the tasks involve just engineering and when we look into the past it's pretty amazing what mankind has come up with so far and actually achieved. A good example is the LHC which is an amazing accomplishment, as well as partially autonomous probes that go to other planets and there is even one coming up that is going to an asteroid for some tests that may someday save human kind. How about the James Webb Telescope, or even the Hubble, and there are three more amazing telescopes coming up.

We all believe what we see working already, it's the ability to reason into the future that sets us apart from both the firm believers and the stubborn naysayers. Note i am saying 'reason' into the future not foretelling the future. We can not foretell the future at least not yet, but we can reason out what may or may not happen. When we do this we use the most intelligent arguments we can find and we apply some heuristic thinking that we gained from past experience. That sometimes includes listening to the experts in the fields of interest. In our culture it is acceptable to counter an experts opinion but it usually requires solid proof or at least a reasonable theory that can be accepted by peers.
What this all means is that we dont just throw a die and use the result to tell us what to believe may happen in the future, we use the most intelligent information we have at the time to make a judgement. I am making the prediction that it will happen because that is what the experts in the associated fields say and i have no absolute proof that they are just making it all up. Could they really be making it all up? Sure, human nature, but since there are so many in agreement i think the most intelligent judgement is to believe them. Of course time will tell there's no getting around that.

 

Calling the actual scientists "swindlers and raconteurs" are YOUR words not mine.

"I'll believe it when i see it" is the scientific method that makes sure intelligent guesses are correct.

Saying it works scientifically with the remainder of the tasks involve just engineering is classic marketing. Engineering is always what matters when actually building things like grid-scale power generation. The root problem is not fundamental physics in fusion energy generation the root problem is the engineering and technology we need to create from a field of science that's still evolving. We don’t even yet know what we don’t know.
This is the dream for a actual grid scale power plant: https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant

11:17 He explains that Fusion is easy, plasma engineering is hard.

So many scientists from so many different countries are true believers in the faith but it takes massive amounts of money to follow that dream. Follow the track record.
https://www.discovermagazine.com/technology/why-nuclear-fusion-is-always-30-years-away#.WqIVWWaZPOQ
https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2017.0431
https://royalsocietypublishing.org/doi/10.1098/rsta.2017.0444

 

"I'll believe it when i see it" is the scientific method that makes sure intelligent guesses are correct.

Saying it works scientifically with the remainder of the tasks involve just engineering is classic marketing. Engineering is always what matters when actually building things like grid-scale power generation. The root problem is not fundamental physics in fusion energy generation the root problem is the engineering and technology we need to create from a field of science that's still evolving. We don’t even yet know what we don’t know.
This is the dream for a actual grid scale power plant: https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant

11:17 He explains that Fusion is easy, plasma engineering is hard.

So many scientists from so many different countries are true believers in the faith but it takes massive amounts of money to follow that dream. Follow the track record.
https://www.discovermagazine.com/technology/why-nuclear-fusion-is-always-30-years-away#.WqIVWWaZPOQ
https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2017.0431
https://royalsocietypublishing.org/doi/10.1098/rsta.2017.0444

Well i am not saying that it is definitely absolutely possible, i am saying that all logical roads lead to the strong suggestion that it does work, and that 'suggestion' is getting stronger and stronger with time which is a good indicator. Just becomes something is 'hard' to do doesnt mean we can say that it will most likely not happen. Yeah plasma is difficult but not impossible.
There are many things that can go wrong such as not being able to engineer a needed material or even lack of funding.
I said the science was clear not the engineering because it took time for them to declare that it was really scientifically possible to do it on Earth. We always knew it was 'possible' in general because it happens in nature, but to do it on Earth had to be proved and it was proved. The tasks now involve engineering. History tells us the same thing happened with the Shuttle. There were roadblocks that had to be overcome, and they were. Had it gone on, it would have gotten better except maybe the cost which was too high.

IF you are talking about "in our lifetime" then that may not be possible and that's unfortunate because it will be a glorious day for mankind when it finally gets here. In the mean time maybe i'll fire up my solar panels

Anyway, when people talk about things that may or may be true or not they often assign a confidence level to that topic. My confidence level is about 90 percent for practical fusion. I wonder if you can place a confidence level on your belief or lack thereof for this and we are talking practical and supplying electrical energy to at least several cities.

 

Well i am not saying that it is definitely absolutely possible, i am saying that all logical roads lead to the strong suggestion that it does work, and that 'suggestion' is getting stronger and stronger with time which is a good indicator. Just becomes something is 'hard' to do doesnt mean we can say that it will most likely not happen. Yeah plasma is difficult but not impossible.
There are many things that can go wrong such as not being able to engineer a needed material or even lack of funding.
I said the science was clear not the engineering because it took time for them to declare that it was really scientifically possible to do it on Earth. We always knew it was 'possible' in general because it happens in nature, but to do it on Earth had to be proved and it was proved. The tasks now involve engineering. History tells us the same thing happened with the Shuttle. There were roadblocks that had to be overcome, and they were. Had it gone on, it would have gotten better except maybe the cost which was too high.

IF you are talking about "in our lifetime" then that may not be possible and that's unfortunate because it will be a glorious day for mankind when it finally gets here. In the mean time maybe i'll fire up my solar panels

The bottom line is will it be possible to make money with fusion energy. Even if it all works as planned it just might not be competitive with that fusion generator in the sky for a long time.

 

Well i am not saying that it is definitely absolutely possible, i am saying that all logical roads lead to the strong suggestion that it does work, and that 'suggestion' is getting stronger and stronger with time which is a good indicator.

But that's just the thing. The intrinsic mechanisms involved suggest precisely otherwise.

Fusion requires a huge amount of energy to drive the deuterium together to form helium. This is NOT a chain reaction! The process demands a continuous "push" in order to keep things going.

Fission on the other hand is does NOT require sustained energy input. The ejected neutrons from the very first reaction lead to even more reactions and so forth. It is an unstable system and the reaction is easily initiated by external forces.

So if there is any use for fusion it must be for some utilitarian purpose. Because it can NEVER generate excess energy. It's the atomic analogue of an endothermic reaction. (And fission could thus be correspondingly categorized as "exothermic".)

 

But that's just the thing. The intrinsic mechanisms involved suggest precisely otherwise.

Fusion requires a huge amount of energy to drive the deuterium together to form helium. This is NOT a chain reaction! The process demands a continuous "push" in order to keep things going.

Fission on the other hand is does NOT require sustained energy input. The ejected neutrons from the very first reaction lead to even more reactions and so forth. It is an unstable system and the reaction is easily initiated by external forces.

So if there is any use for fusion it must be for some utilitarian purpose. Because it can NEVER generate excess energy. It's the atomic analogue of an endothermic reaction. (And fission could thus be correspondingly categorized as "exothermic".)

Where did you learn physics? You can have energy gain in the fusion plasma without ignition. At ignition the push process becomes self-sustaining and self-heating with Q plasma in theory becoming infinite, this is why H-bombs explode with equivalent megatons of energy. The root problem is commercial breakeven, can the investors make money, not simple fusion physics you don't seem to understand.

 

Where did you learn physics? You can have energy gain in the fusion plasma without ignition. At ignition the push process becomes self-sustaining and self-heating with Q plasma in theory becoming infinite

From Wikipedia:

In order to undergo fusion, the fuel atoms need to be given enough kinetic energy to approach each other closely enough for the strong force to overcome the electrostatic repulsion. The amount of kinetic energy needed to bring the fuel atoms close enough is known as the "Coulomb barrier". Ways of providing this energy include speeding up atoms in a particle accelerator, or heating them to high temperatures.

So the temperatures/pressures involved really must be CONTINUOUSLY maintained. Which of course means that energy has to be pumped into the system on a NONSTOP basis. Factor in heat loss and you get net NEGATIVE yield.

Again just look at the current state of the art. Not a SINGLE demonstration of self-sustained fusion power. For that matter there probably never will be either.

 

From Wikipedia:



So the temperatures/pressures involved really must be CONTINUOUSLY maintained. Which of course means that energy has to be pumped into the system on a NONSTOP basis. Factor in heat loss and you get net NEGATIVE yield.

Again just look at the current state of the art. Not a SINGLE demonstration of self-sustained fusion power. For that matter there probably never will be either.

More proof that you have no idea what you're talking about.

The extra energy comes from mass to energy conversion of strong nuclear force particle interactions. The prime problem is confinement not energy production from the fusion process. The strong nuclear force is strongest of all the fundamental forces, once the triplet of fusion happens the electromagnetic energy for two nucleons can be orders of magnitude smaller than the energy of their strong interaction.
https://www.britannica.com/science/nuclear-fusion/Fusion-reactions-in-stars

Energy is released in a nuclear reaction if the total mass of the resultant particles is less than the mass of the initial reactants. To illustrate, suppose two nuclei, labeled X and a, react to form two other nuclei, Y and b, denotedX + a → Y + b.The particles a and b are often nucleons, either protons or neutrons, but in general can be any nuclei. Assuming that none of the particles is internally excited (i.e., each is in its ground state), the energy quantity called the Q-value for this reaction is defined asQ = (mx + ma − mb − my)c2,where the m-letters refer to the mass of each particle and c is the speed of light. When the energy value Q is positive, the reaction is exoergic; when Q is negative, the reaction is endoergic (i.e., absorbs energy). When both the total proton number and the total neutron number are preserved before and after the reaction (as in D-T reactions), then the Q-value can be expressed in terms of the binding energy B of each particle asQ = By + Bb − Bx − Ba.


The D-T fusion reaction has a positive Q-value of 2.8 × 10−12 joule. The H-H fusion reaction is also exoergic, with a Q-value of 6.7 × 10−14 joule. To develop a sense for these figures, one might consider that one metric ton (1,000 kg, or almost 2,205 pounds) of deuterium would contain roughly 3 × 1032 atoms. If one ton of deuterium were to be consumed through the fusion reaction with tritium, the energy released would be 8.4 × 1020 joules. This can be compared with the energy content of one ton of coal—namely, 2.9 × 1010 joules. In other words, one ton of deuterium has the energy equivalent of approximately 29 billion tons of coal.