Why people are so optimistical to Polywell?

[KitemanSA]

Joseph,
Here is a basic question for you.
Suppost you had a cold plasma where the ditribution of ion velocities was broader than the Maxwell-Boltzmann distribution:
would the laws of physics require the distribution to tighten up until the M-B distribution was reached?

yes it would. ok i'm curious now; what's your point?

That the hypothesized "annealing" process seems based on that law of physics and is thus not necessarily in the relm of the "perpetual motion" machine.

[KitemanSA]

The cold Maxwellian distro is TIGHTER in energy distribution than the hot center. This is annealing.

I have read just now.
Would you like to say that radial ion stream when it moves out of hot center will have lower temperature?

The radial ion "stream" will climb the potential well, converting kinetic energy into potential, cooling down. In the mean time, the degree of "chaos...velocity spread, whatever you call it" will be ~uneffected by climbing the potential well. When the ions have reach zero RADIAL velocity due to the well, any distribution of tangential velocities that is broader than the M-B distro should tighten up, becoming MORE mono-energetic, not less.

As was pointed out, the ions at the center will have a variance in "radial" velocity too, but that just defines where on the way up the well the ion comes to a radial rest. And they all do, other than the ones destined to be lost OVER the edge of the well.

Of course, the data may prove me wrong about all this. Wish we had some!

[Joseph Chikva]

And now you have heard of a hypothetical third method. Annealing.

I know annealing only in metal processing. Or you cannot explain me because of my bad English, or may be Polywell inventors discovered a new phenomenon.
Because if we would not dissipate energy and energy remains in reaction zone you can calculate M-B distribution as much as you wish.

[Joseph Chikva]

The radial ion "stream" will climb the potential well, converting kinetic energy into potential, cooling down.

We live in potential well caused by gravitation of Earth. For escaping that we need some kinetic energy. Yes?
Do you think that throwing a hot subject upwards its temperature decreases because kinetic energy converts into the potential?
Or if that subject is cooling down that is possible only thanks to radiation and heat transfer with air?

[D Tibbets]

The radial ion "stream" will climb the potential well, converting kinetic energy into potential, cooling down.

We live in potential well caused by gravitation of Earth. For escaping that we need some kinetic energy. Yes?
Do you think that throwing a hot subject upwards its temperature decreases because kinetic energy converts into the potential?
Or if that subject is cooling down that is possible only thanks to radiation and heat transfer with air?

Your Earth gravity analogy is appropriate, but your baseline- starting point is wrong. The starting point for the ions introduced into the Polywell is way above the surface of the Earth in your annalogy. They are moving slow, they are cool, they have low kinetic energy (all these terms are synonymous. Just take a rock or asteroid that is caught in Earth's gravity well, it will accelerate until it passes or hits the Earth (center of the Polywell. If you place a trampoline just above the surface the rock will bounce back up . A better comparison might be a satellite in a highly elliptical orbit about the earth. At apogee it is slowest and furthest from the Earth. It has maximum potential energy and minimal kinetic energy within the system. As the satellite continues it's orbit it approaches closer to the Earth, it picks up kinetic energy from the Earth's gravitational field (the electrical field in a Polywell) until it reaches paragee where it has the maximum of kinetic energy and and minimum of potential energy. It will continue to orbit in such a manner for a very long time so long as there is no counter force (like thin atmospheric friction). At the top of the potential well (gravitaional well) the speed is lowest. If you take the example to extremes the resultant maximum and minimum speeds can be higher. Use the Earth's magnetic well, but constrict it to the dimensions of a black hole. Now the elliptical orbit can be more pronounced- because paragee orbital radius can be much smaller- thus speed greater,, the apogee orbit can also be much slower (because the orbital free fall speed could be much smaller ( orbit remains elliptical about a center without hitting it). This can be similar to a well focused / confluent set of ion orbits or oscillations in the Polywell. The better the confluence the greater the maximal speed and the minimal speed, until you approach zero on one end and infinity (or the speed of light) on the other end. Of course the Earth is not a black hole, and the Polywell cannot have total ion confluence to a central point ( the virtual anode that forms would prevent this), but if you can approach close enough to this extreme limit, you will have hot ions in the center and very cold ions on the edge. The other extreme would be perfectly circular orbits. That is also an unobtainable extreme, because random collisions would prevent this. You might have an average circular orbital characteristics, but a certain proportion of the ions will be in variable elliptical orbits. These would undergo differential collisionality as they entered slower orbital domains (with the circularly orbiting ions at that radius from the center). So there is unavoidable annealing *. The question is to what extent this happens to what portion of the ions, and if this results in a thermalized spread different than those ions primarily in orbits with different maximal and near points (apogees and paragees) and if these differences in velocity results in a delta velocity in a region that comes to dominate the other delta V (thermalized spread ) in other regions.

The short version of this is that at certain ideal MFP, machine size, and density in a spherical geometry has to result in this annealing effect. The magnitude of this effect will change as conditions change, but never reach zero in a collisional plasma.

* Annealing is a term chosen by Bussard, etel presumably because they could not find a better term. Annealing means to reduce stresses, imbalances in a substance. Not only in an end product, but during the processing of a product- like repeated annealing of iron as it is hammered into a horse shoe or what ever. In this sense 'annealing' is a descriptive term as the ions are relaxed into a thermalized state at the beggining of each elliptical orbit. Remember the beginning of each orbit is at the edge , not at the center (or the surface of the Earth in your analogy). It is the physics that dictates that this starting energy will be a narrow thermalized cluster about a low energy average. This is a simplistic view of a complex dynamic plasma, but it gives the trends.
It is also improbable, or impossible (?) to maintain for very long. If you pulse some monoenergetic ions int a spherical potential well, the annealing will slow the overall thermalization process in the hotter regions of the well, but will lose out in the end (become a small correction to the overall thermalized spread that is probably very small). But if you maintain a flow of new monoenergetic ions at the edge of the potential well and/ or the ion dwell time is short enough, then this annealing deviation from a perfect statistical thermalized spread will become increasingly significant, and even dominating . The only real argument is the time intervals involved in a given system. A true Maxwll - Boltzmann distribution describes a plasma without borders or any other extrenal forces effecting the plasma.

Dan Tibbets

[D Tibbets]

PS: You are confusing terms. If you throw a rock upwards it slows down and transfers energy to the Earth's gravitational well. We are talking about velocity here. Always, it is velocity that is important. Temperature is often used synonymously but remember that this is sloppy terminology, and can be confusing.

Dan Tibbets

[KitemanSA]

The radial ion "stream" will climb the potential well, converting kinetic energy into potential, cooling down.

We live in potential well caused by gravitation of Earth. For escaping that we need some kinetic energy. Yes?
Do you think that throwing a hot subject upwards its temperature decreases because kinetic energy converts into the potential?
Or if that subject is cooling down that is possible only thanks to radiation and heat transfer with air?

If I sat at the bottom of a gravity well and had a flask of very hot, ALMOST mono-energetic gas with a "temperature" just hot enough to have the molecules ALMOST escape that gravity well, and I were to release that gas at the very bottom of that well, then yes, as the gas ALMOST reached escape, it would stop, and be VERY cold. This is not a brick o stuff at a temperature. These are ions that GAIN a set amount of energy falling into the well becoming "hot", get "thermalized" a bit, LOSE the energy climbing back out of the well becoming cold, and "thermalize" to a tighter distribution. Hypothetically.

[Joseph Chikva]

PS: You are confusing terms. If you throw a rock upwards it slows down and transfers energy to the Earth's gravitational well.

Bussard offered to "throw" ions "upwards" (radially in the same manner as in analogy), they slows down and transfer energy to electrons' electrostatic well.

[Joseph Chikva]

The radial ion "stream" will climb the potential well, converting kinetic energy into potential, cooling down.

We live in potential well caused by gravitation of Earth. For escaping that we need some kinetic energy. Yes?
Do you think that throwing a hot subject upwards its temperature decreases because kinetic energy converts into the potential?
Or if that subject is cooling down that is possible only thanks to radiation and heat transfer with air?

If I sat at the bottom of a gravity well and had a flask of very hot, ALMOST mono-energetic gas with a "temperature" just hot enough to have the molecules ALMOST escape that gravity well, and I were to release that gas at the very bottom of that well, then yes, as the gas ALMOST reached escape, it would stop, and be VERY cold. This is not a brick o stuff at a temperature. These are ions that GAIN a set amount of energy falling into the well becoming "hot", get "thermalized" a bit, LOSE the energy climbing back out of the well becoming cold, and "thermalize" to a tighter distribution. Hypothetically.

If we talk about thermal distribution I think that ions being in any field would have distribution different from M-B.
But temperature of ions at the Polywell’s edge will not lower than in center at the expense of that they move in electrostatic well. You are wrong.

[93143]

Have you ever seen an entropy profile through a shock wave?

[Joseph Chikva]

Have you ever seen an entropy profile through a shock wave?

And?

[Giorgio]

Have you ever seen an entropy profile through a shock wave?

I am afraid you will just add more confusion with that example.
There are some terminology issues here that need to be cleared if we want to make him understand.

@Joseph Chikva
Convert the way you are seeing the ions from a thermodynamic environment to a pure mechanical system.

We have a big permanent magnet in the middle (potential well).
We have a gun shooting metal balls (ions).
We shot the balls toward the magnet at a speed so that they will overpass the magnet, but still feel his influence. At a certain point the influence of the magnet will stop most of the metal balls and attract them back toward it.

If you plot the speed on a graph, you will see cusps.
At maximum distance "X" from the magnet the ball will be at zero speed (bottom of the cusp or COLD).
At minimum distance from the magnet the ball will have maximum speed (top of the cusp or HOT).

Makes more sense now?

[Joseph Chikva]

Have you ever seen an entropy profile through a shock wave?

I am afraid you will just add more confusion with that example.
There are some terminology issues here that need to be cleared if we want to make him understand.

@Joseph Chikva
Convert the way you are seeing the ions from a thermodynamic environment to a pure mechanical system.

We have a big permanent magnet in the middle (potential well).
We have a gun shooting metal balls (ions).
We shot the balls toward the magnet at a speed so that they will overpass the magnet, but still feel his influence. At a certain point the influence of the magnet will stop most of the metal balls and attract them back toward it.

If you plot the speed on a graph, you will see cusps.
At maximum distance "X" from the magnet the ball will be at zero speed (bottom of the cusp or COLD).
At minimum distance from the magnet the ball will have maximum speed (top of the cusp or HOT).

Makes more sense now?

So, you mean too that when the cloud (stream) of balls or ions stops they are COLD and when has non-zero velocity - HOT?
The picture is a little bit different: you have a gradient of velocities of arranged (coherent) moving but from this doesn't follow at all that you have also a gradient of temperatures.

[KitemanSA]

So, you mean too that when the cloud (stream) of balls or ions stops they are COLD and when has non-zero velocity - HOT?
The picture is a little bit different: you have a gradient of velocities of arranged (coherent) moving but from this doesn't follow at all that you have also a gradient of temperatures.

So perhaps we have finally found the linguistic issue.

In polywell, the velocity is generally discussed as "temperature" using the (IIRC) 1eV ~ 11.6 kK equation. So MONO-energetic plasmas moving along with 10keV of kinetic energy are considered darned HOT and those with 0eV of kinetic energy are considered COLD. Near the center, the HOT plasma "thermalizes" (spreads its energy distribution) while at the COLD end it does it again (narrows); hypothetically.

All the discussions you have been making appear to assume a hot MAXWELLIAN plasma. That is NOT Polywell (we hope).

[Joseph Chikva]

So perhaps we have finally found the linguistic issue.

It is not only linguistic issue because:

In polywell, the velocity is generally discussed as "temperature" using the (IIRC) 1eV ~ 11.6 kK equation. So MONO-energetic plasmas moving along with 10keV of kinetic energy are considered darned HOT and those with 0eV of kinetic energy are considered COLD.

As a rule in nuclear physics any energy and mass calculated in eV-s. And temperature as well.
When you quote 1eV ~ 11.6 kK - this is temperature that is proportional to average energy of particle in distribution. As you maintained "K" that is temperature and not velocity.

When you talk any energy 1 eV = 1.6E-19 J

When you talk about mass, e.g. electron's mass 9.1E-31 kg = ~0.511 MeV

Etc.

And I do not know on what you hope but "thermalized" means the increase of temperature that is not mono-energetic but Maxwelian or having another distribution.

Why you call moving mono-energetic plasma "HOT" and not "HEAVY"?

I did not wait that would be forced to explain here so simple things.