Beyond my ken.ladajo wrote:I guess I was getting at the idea that it is not a primary mechanism or concern. Just something to be aware of.
Can you answer these questions?
Time will tell. Be nice to have some actual test data and analysis in public.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
So was Mark Suppes. But he seems to have fallen off the planet of late IRT Polywell.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
~
Cusp/ Wiffleball confinement refers to the surface area of the plasma 'quasi' sphere in relation to the cusp loss surface area. Use the Wiffleball analogy of bouncing balls- it is more complicated with consideration of magnetic mirroring, etc., but the final result is similar. Whether the balls are ions or electrons, if they hit a hole with outward momentum, they will exit. The confinement is often referenced as the number of passes/ bounces before this ball hits a hole. The number is similar for ions and electrons when only talking about magnetic cusp confinement in isolation. The magnetic cusp confinement is the same when considering the number of bounces/ distance traveled. At the same energy, the ions are traveling ~ 1/60th or less slower, so in terms of magnetic cusp confinement time the ions reside inside for much longer than the electrons (assuming the electrons are replaced faster so that the net neutral plasma is maintained). Note that this ignores the ExB magnetic confinement losses of the ions which is not related to the cusp loss surface area ratios and is perhaps greater than the electron ExB losses by a factor of over 60- at least when the magnet surfaces are far apart, the picture may change some at the nubs, etc. because even one electron gyroradius motion might reach a surface ).ladajo wrote:Dan, what are you saying here? Please clarify.Note that the ion magnetic confinement benefits from the Wiffleball effect also. The confinement time may increase from the cusp confinement of perhaps 60 passes to up to several thousand passes (taken from the patent application).
As I understand, Ions are attracted, not "confined". If they do not fuse, and escape via the vacuum maintenance system, then there is the opportunity to recover and recycle them as fuel.
Power In is a function of driving (e-) and the well. Net Power is a result of sufficient fusion events to generate more power than used to make the well. It seems that you are losing sight of the basic concept to some degree.
Magnetically Confine Electrons, and thus confined Electrons create a large negative potential in the center of the magnetic fields.
Limit Electron Loss Rate via Wiffleball Dynamic (Magnetic Cusp Pinching).
Positively Charged Fuel Ions are Electrostatically Attracted to the Big Negative.
Ions seeking center collide with each other creating head to head and offset events.
Now add the excess electrons so that the plasma is negatively charged by ~ 1 ppm. This is obtainable, and sufficient for the ions to be electrostatically contained, and that greatly modifies the above considerations. I said that an ion that hits a hole with outward momentum exits, but with the potential well the ions do not have outward momentum at this point. Effectively they do not see the cusps and their containment is purely electrostatic. There are two exceptions, when the fuel ions are up scattered, they have outward momentum when they hit a radius from the center where the cusp is. This means that as the plasma tries to thermalize, the higher energy ions escape and this modifies the thermalization distribution in the surviving contained plasma- at least for the ion population. This added to claimed edge annealing effects on the ions provide possible mechanisms for profound changes in the thermalization process of the ions and claimed 'mono' energetic ion populations throughout the lifetime of the average fuel ion. The other exception to ion electrostatic confinement is ions that are born with KE far above the potential well voltage. This would be fusion produced ions, the alpha particles from P-B11 fusion, and also to the He3 and Tritium fusion ions from D-D fusion. While they are slowed some by the potential well, they keep most of their KE and they either hit the Wiffleball border and bounce back, or they hit a cusp and escape. This assumes the distance from the Wiffleball border to the magnet surfaces are great enough that the gyroradius of the fusion ion does not carry it to the magnet on one pass. As the fusion ions are fast their MFP is great enough that ExB drift is much less of an issue so they will tend to bounce around till they hit a cusp. They will not heat the plasma much (this is why Polywells are not ignition machines), nor will they heat the magnets much through impacts. This has significant implications. R. Nebel stated that ~ 3.5 Tesla B fields in a 3 (?) meter diameter machine would satisfy the gryroradius concerns. R.Nebel also said that the lifetime of an alpha particle was a few thousand passes, the same as the electrons and this reflects the magnetic confinement of ions being comparable to that of the electrons (ignoring ExB drift) when electrostatic confinement of the ions is not dominate.
Dan Tibbets
To error is human... and I'm very human.
Dan, I think you are off track here. I understand confinement. But in Polywell, the point is not to Magnetically Confine Ions. They are bigger, heavier, and they are intended to be Electrostatically attracted to the concentration of Magnetically Confined (e-)s.Whether the balls are ions or electrons, if they hit a hole with outward momentum, they will exit. The confinement is often referenced as the number of passes/ bounces before this ball hits a hole. The number is similar for ions and electrons when only talking about magnetic cusp confinement in isolation.
The number is NOT similar for Ions and (e-)s. That is what makes the Polywell concept attractive. It does not seek to magnetically confine (e-)s. For a given field strength, Ions will be magnitudes less affected than (e-)s.
The magnetic fields in Polywell are not meant to focus Ions. The fields do impact them, but are not strong enough (nor desired to be) to drive them.
The fields exist for (e-) control. The cusps contraction occuring during wiffleball mode is for (e-) containment. As I understand, the confinement studies were done for (e-) plasma alone.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
Do we care if ions escape?
Annealing would seem to be more important to ion energy distribution across the core. I don't think an upscattered higher energy ion is going to stopped by the B-Field.
Edit: Corrected typo on high energy ion escaping, vice not.
Annealing would seem to be more important to ion energy distribution across the core. I don't think an upscattered higher energy ion is going to stopped by the B-Field.
Edit: Corrected typo on high energy ion escaping, vice not.
Last edited by ladajo on Wed Feb 06, 2013 1:24 pm, edited 1 time in total.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
Yes annealing might rehabilitate some of the upscattered ions, but I guess that many will hit a cusp and exit and that is also good from a thermalization perspective, though it does cost some energy as the escaping upscattered ion has some retained energy after escaping the potential well and it picks up additional energy from the positive potential on the magnrid. The key here is that these escaping ions are much fewer than the electrons escaping, thus the energy gain from electron recirculation dominates over ion losses.hanelyp wrote:Primary confinement of ions in a polywell is the electric potential well. But the magnetic field gives annealing a chance to recover upscattered ions before they completely escape.
Certainly FUEL ion containment is by electrostatic means except for the up scattered examples. If there was not ions that were up scattered to outward energies greater than the potential well, then fuel ion containment might approach infinity. This is obviously not the case. Fuel ion containment in the Polywell may optimistically reach a few seconds, provided they survive that long before fusion. A few seconds of effective electrostatic confinement is certainly much worse than containment obtained in Tokamaks, but the obtainable density more than makes up for the difference in terms of the triple product. The mono energetic characteristics are an added benefit but not critical for profitable D-D fusion according to R. Nebel.
As for central focus, the potential well may promote this, but any ions that exceed the Wiffleball border radius (up scattered) enters the magnetic domain and bounce back (or occasionally escape) with increased angular momentum. Bussard mentioned this as one of the things that limits the obtainable central focus/ confluence.
Annealing occurs between ions on the edge at low energies. The Coulomb scattering cross section increases rapidly in relation to the slow collision speeds of two ions. But an up scattered ion may still have several thousand eV of more KE and the conditionality is much less than the border energy of perhaps 10-100 eV for the average ion close to the top of their potential well. So, the up scattered ions will participate much less in the annealing process in this edge region. This is why I suspect annealing does not have much effect on ions that are up scattered more than a small amount.
As for the lifetime of the ions that are not contained by the potential well (electrostatic confinement) they are contained by the same mechanism as the electrons (except no recirculation). The alpha particles fit this description with their KEs of millions of eV. The potential well would slow them as they travel outward by only~ 10%. And I use R.Nebel's quote of a few thousand passes to mean the alphas leave about as fast as the Wiffleball Trapping Factor dependent electron cusp losses- a few thousand passes. It makes sense to me, and it is also what R. Nebel claims.
A. Carlson claimed that the alphas would leave- through a cusp, after only ~ 10 passes. But, I assume he was using Mirror machine magnetic cusp confinement numbers while ignoring the ~ 100(?) fold improvement due to the Wiffleball effect.
The Wiffleball effect is an absolute cornerstone of the machine's success. This magnetic confinement operates on any reasonable charged particle and is what I've tried to emphasize. Of course the additional brilliant idea of using excess electrons to create a potential well in a non neutral plasma is the additional step that decouples the electron confinement from the ion confinement and allows for electrostatic confinement of the ions of interest, which is much more efficient. The separation is not absolute and this has consequences, but the ion electrostatic containment is good enough to limit losses to perhaps 1% or less than the magnetic containment electron losses.
Some confusion may come from claims of ~ 100,000 passes electron containment, while Wiffleball containment is in the low thousands;but recall that this includes an ~ 10 X improvement through recirculation.
Dan Tibbets
To error is human... and I'm very human.
Losing Ions is not near as important as (e-)s.
Yes, Ions must oscillate enough times through the core to provide a decent chance of a collision/fusion.
And yes, the turn around zone of the ions providing an interaction zone for higher energy upscatters seeking to escape the electrostatic well to transfer some KE to the lower energy ones is important to some degree. But this is mainly a function of the well, not the fields.
The mass for an ion is MUCH more than an (e-), and the magnetic field levels envisioned are about controlling (e-) masses, not ion masses.
Yes, Ions must oscillate enough times through the core to provide a decent chance of a collision/fusion.
And yes, the turn around zone of the ions providing an interaction zone for higher energy upscatters seeking to escape the electrostatic well to transfer some KE to the lower energy ones is important to some degree. But this is mainly a function of the well, not the fields.
The mass for an ion is MUCH more than an (e-), and the magnetic field levels envisioned are about controlling (e-) masses, not ion masses.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
I truly think you have this backwards. First, es lost are often recycled. Those that aren't return much of their energy to the system before they reach the chamber wall. Only those that make it thru the field and reach the MaGrid are total losses, and they only loose the amount of energy that a D ion loses.ladajo wrote:Losing Ions is not near as important as (e-)s.
I understand the "recirc" or "oscillation" aspect for both particle species. I also understand that the motive force and mechanism is different for each, which is the point of Polywell.
My point is that the magnetic field exists for the confinement of electrons. Anything else it may nudge or improve is a bonus. I am also sure that it impacts ions, just magnitudes less than it does (e-)s.
As for ions, the oft quoted annealing process is helpful to the distribution function for the fuel. But is it a must? I think that remains to be seen. Also, it can not be unhelpful as we understand it.
If an ion escapes, there are ways to recover it, or its energy. The loss of (e-)s is a direct impact to power in, which in turn is directly related to Q.
Without confinement (wiffleball) it is a bust. And EMC2 has publically stated directly and in publically available government documents that confinement (wiffleball) is proven. I have never thought they were talking about ions in this context.
Wiffleball is not about ions, it is about (e-)s.
My point is that the magnetic field exists for the confinement of electrons. Anything else it may nudge or improve is a bonus. I am also sure that it impacts ions, just magnitudes less than it does (e-)s.
As for ions, the oft quoted annealing process is helpful to the distribution function for the fuel. But is it a must? I think that remains to be seen. Also, it can not be unhelpful as we understand it.
If an ion escapes, there are ways to recover it, or its energy. The loss of (e-)s is a direct impact to power in, which in turn is directly related to Q.
Without confinement (wiffleball) it is a bust. And EMC2 has publically stated directly and in publically available government documents that confinement (wiffleball) is proven. I have never thought they were talking about ions in this context.
Wiffleball is not about ions, it is about (e-)s.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
Electron mass(rest): 9.109 x 10-31kg
Deuterium mass(rest): 3.34330 x 10-27kg
Trititum mass (rest):5.00736 × 10-27 kg
Boron-11 mass (rest):1.83 × 10-26 kg
Proton mass (rest):1.67262 × 10-27 kg
4 orders of magnitude difference at best, 5 orders with Boron (e-) to fuel, and corrosponding inertial resistance to magnetic field accelleration.
a=F/m Higher mass means lower accelleration (4 to 5 orders of magnitude worth). The charge effects are of the same order of magnitude.
Think of the field requirements in ITER which are derived from need to confine ions compared to field requirements for Polywell.
ITER 15 to 20T, Polywell, 3 to 5T.
Ions are not going to see the magnetic cusps the same way as (e-)s.
The cusps will appear to be much bigger.
Deuterium mass(rest): 3.34330 x 10-27kg
Trititum mass (rest):5.00736 × 10-27 kg
Boron-11 mass (rest):1.83 × 10-26 kg
Proton mass (rest):1.67262 × 10-27 kg
4 orders of magnitude difference at best, 5 orders with Boron (e-) to fuel, and corrosponding inertial resistance to magnetic field accelleration.
a=F/m Higher mass means lower accelleration (4 to 5 orders of magnitude worth). The charge effects are of the same order of magnitude.
Think of the field requirements in ITER which are derived from need to confine ions compared to field requirements for Polywell.
ITER 15 to 20T, Polywell, 3 to 5T.
Ions are not going to see the magnetic cusps the same way as (e-)s.
The cusps will appear to be much bigger.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)