Why do fusors work?

[Dan Tibbets]

Steven Sesselmann. Your assertions that nikel 62 is the zero point and fusion and fison exothermic reactions are either pos or negative ( greater or less potential energy) is not accurate. Nickel 62 has the smallest potential energy of any possible nucleus. A proton is not bound so has no potential energy defined . Actually the potential energy often is expresed as the sum of the repulsive energy (electromagnetic repulsion of protons), and the attractive energy of the Strong force. This attractive energy is by convention given a negative value (just like gravity). At Nickel62 the difference between these two forces is at a maximum( the most negative sum is reached). Past Nickel 62 the electromagnetic repulsion is growing faster than the Strong force attraction, as such the potential energy inside the nucleus is increasing (becoming less negative). At some point the net potential energy becomes maximum (~0) and the nucleus quickly falls apart. The position of Nickel 52 at the lowest potential energy state (most stable or most compact) is obvious from the Nuclear Binding Energy per Nucleon graphs. It is even more obvious if you flip the graph upside down (as it would be with a negative value assigned to the attractive Strong force component).

When light nuclei fuse you are harvesting the excess strong force energy. When you fission heavy elements you are harvesting the excess electromagnetic energy (compared to Nickel 62). The missing mass is important, but even more important is the balance of the two forces that make up this missing mass. primarily the repulsive Electromagnetic and attractive Strong forces.

I don't know how this would affect your relativity arguements . If we are at the baseline, increased speed of particles to relativistic speeds would not change their decay or reaction ratesin their frame of reference. From our frame of reference the reaction rates would seem to slow down - a good example is the survival of the Muon as it reaches the Earths surface. Without relativistic effects it would decay much too fast to survive it's several hundred mile trip through the atmosphere, from where it was born to the surface of the Earth. This would seem to be the reverse of what you are proposing. Traveling slower than us would result in faster reaction as percieved from our frame of reference, but how to do this ?

Dan Tibbets

[Chris Bradley]

Dan DT wrote:
> the potential energy often is expresed as the sum of the repulsive energy (electromagnetic repulsion of protons), and the attractive energy of the Strong force. This attractive energy is by convention given a negative value (just like gravity). At Nickel62 the difference between these two forces is at a maximum( the most negative sum is reached). Past Nickel 62 the electromagnetic repulsion is growing faster than the Strong force attraction

If the strong force does not balance the electromagnetic force perfectly, in any extant nucleus, then what other forces are at work to hold the nucleus together?

This just doesn't add up (whichever sign you attribute to each!!)

[Steven Sesselmann]

With all due respect to 300 years of science, if it can't answer Alex's simple question it's no b...dy good.
.

I would like to ask Alex a question, what is hypothetically the most negative charge a grid can have?

Steven

[Steven Sesselmann]

Dan Tibbets Wrote...
"Traveling slower than us would result in faster reaction as percieved from our frame of reference, but how to do this ?"

Dan..., you are knocking at the door, now you just have to find the key.

Steven

[Dan Tibbets]

Chris Bradly, i t seems few understand the Binding energy per nucleon relatio0nship (I cannot guarentee I'm not included in that group).

When the electromagnetic repulsion balances against the strong attraction, then the nucleus is balancing on the cusp of falling apart. This condition is approached as heavier nuclei are reached. It becomes prevalent beyond lead and just past plutonium there are no isotopes that can hold themselves together for long (with the strong force). Of course it varies with neutron count due to weak force and Paul exclusion processes, nucleon paring, etc, but the gross balance competition is between the strong force and the electromagnetic force (with a few variations like helium 4). The most stable, most dense nucleus, and the nucleus with the least potential energy is Nickel62. This is not where the two forces balance out. This is where the strong force has the greatest dominance. A nucleus that is ~ 4 nucleons wide is reaching the limiting range where the strong force will increase the attractive binding energy ( negative potential energy) by a greater amount than the acumulating repulsive electromagnetic repulsionby only a relative small amount compared to light nuclei where ALL of the nucleons are close enough together for the very short range strong force to reach across them all. With increasing nuclear diameter, the neighboring nucleons still attract each other, but not so much with nucleons on the other side of the nucleus. It is different for the electromagnetic repulsion because of the greater range of the force. I might add that using a negative value for the attractive force is a convention, but it is not necessary, so long as you keep track of the opposing effects. The attractive energy builds up , but saturates. The repulsive force continuously builds up and it saturates also, but less rapidly. A graph of the two opposing forces have different slopes and at Nickel 62 they cross. Beyond that point the repulsive force increases faster than the attractive force, but the attractive force had a head start because it was increasing faster (becoming more negative by convention) with the lighter nuclei. It takes it a while for the repulsive force to catch up (heaviest elements).
The Nickel 62 is the turn around point, the lowest potential energy possible, but that does not mean it is the point where a balance in established. It is the point where the trends reverse.
Another analogy. A balance scale. One one side is a small pan (representing the volume where the strong force can collect) and a much bigger pan on the opposite side (which represents the much larger volume where the repulsive electromagnetic force can collect).
The strong force lead pellets are added to the small pan at the same rate as lithium pellets are added to the large pan. Initially the scale will swing to the left side( strong force pan side) But the pan is small, additional lead pellets will fall over the side. Now, as additional pellets are added, the lithium pellets are still accumulating and the scale starts swinging to the right. At some point a balance will be reached where the arms are level. This would be ~ lead or beyond. The Nickel 62 is where the lead pan is filled up. This is a simplified analogy. It doesn't take into account that the strong force always continues to increase in a logarithmic fasion ( as does the electromagnetic force, but since this increase becomes progressively less with each step, it approaches a level line (like additional lead pellets falling out of the pan).

Dan Tibbets

[Dan Tibbets]

Concerning transparent grids, if they were transparent/ vertual, the ions could pass back and forth indefinitely in a connectionless plasma, or a plasma that maintained a mono energetic temperature. The would traverse the potential well indefinitely. The problem is that a collisionless plasma is useless. You cannot have fusion without collisions. And scattering Coulomb collisions will always occur more frequently than fusion collisions. You can come close with D-T fusions at ~ 100 KeV (~ 1:10 ratio) and with D-D fusions at several MeV. The problem with the D-D though is that at these energies losses are increasing faster than the fusion rate. Bremsstrulung in particular is a problem as it increases faster than the fusion crossection curve once you are over several hundred KeV. Also other unwanted nuclear reactions become more prevalent.. Even if you can recover the Bremsstrulung losses through a heat engine (steam plant) you can only reach ~ 30% efficiency, and that is not enough to overcome the fusion/ Bremsstrulung rates at these temperatures. If you had a 99% heat to electricity conversion efficiency, thing would change a lot. Concerning conversion, if you have to accelerate your ions to 2 MeV, and you get ~ 3 MeV per fusion, , you would get ~ 5 MeV of heat, converted at 30% efficiency would result in ~ 1.5 MeV of output. This is less than the energy you put into the fuel ions. You are losing ground. Because of this there are compromises needed. The best monoenergetic temperature would probably be somewhere around 100 to 200 KeV. Bussard preferred ~ 80 KeV, but I don't know if he was planing on only burning D-D or if this incorporated recovering the tritium and helium 3 and also burning those secondary fuels where the three fusion crossection curves are different.

Back to thermalization. Upscattering will result in the ions reaching the wall and losing their energy. I don't know the relative rates but it would not be far behind grid collisions, perhaps 1-2 orders of magnitude at best, depending on the temperature - again there would be a compromise between the fusion and scattering crossections. If the gridded fusor can reuse the ions for ~ 10-20 passes, then with a transparent/ virtual/ magnetically shielded cathode (or anode with an Elmor Tuck Watson fusor), them perhaps 100-2000 passes might be achievable. Bussard , etel found that ~ 10,000 or more ion passes was the minimum required ( or > ~ 100,000 electron passes). ~10-100 times more would be needed to achieve good fuel burn up. You need something more. . Without going into details, this is embodied in the Polywell design. There is also a group of MIT graduates types working on something similar.

Dan Tibbets

[Dan Tibbets]

Steve Sesselmann, It is generally accepted that we line in fairly flat space. If we lived near the event horizon of a black hole the relative fusion rates would be faster away from the black hole from out perspective, but I'm not sure how we would interface with this. As far as speed, we are traveling at ~ known velocities relative to distant galaxy clusters, and our movement with the expansion is also known and at least for nearby (several billion light years) the speeds are not reletivistic. . Perhaps if we located a reactor on the opposite side of the observable universe, it would have a much faster percieved fusion rate. But, the transport of the electricity to us might ba a problem.

As for the rest mass/ energy of a proton (or neutron?), if this is actually a result of a velocity in a different frame of reference, I do not see the link to our reality/ reference frame. To a photon the rest mass / velocity in some other dimension may be zero or very close to it. but to increase the fusion rate of these particles from our perspective we would have to speed our selves up, not slow the particles down- that would be decreasing their energy to almost nothing ( in our reality/ frame of reference) and thus eliminating any energy yield for us.
Mmm... I might be knocking on the door, but I don't know what is behind it and I don't have a key.

Dan Tibbets

[Carl Willis]

I feel this thread has been given a fair shake, but the chain of responses is mostly characterized by word salad. We've got wide-ranging and off-topic speculation. A dearth of credible references, or new theoretical developments closely accountable to observed reality. And more than a lion's share of barking-mad nonsense.

It's never been my understanding that off-the-cuff scifi-convention bathroom banter amounts to "Theory." We don't have a general banter forum. (That idea has been proposed, and shot down, several times.) If we did have such, that's where 90% of this thread would belong. But as it is, this is a "Theory" forum.

To get to the point at last: thread's closed.

-Carl