thread for segments files and parameters for simulation runs

[happyjack27]

i.e. through the center of a cusp. from my sims you need to get very near the exact center to have any chance of getting the electron to stay.

I'm still not sure whether you're talking about them staying in the WB itself, or in the exact middle of the WB. Are you thinking they would shoot through and exit an opposing cusp if not lined up properly? I don't think that's a major concern. They should bounce around about 100,000 times before exiting.

not in the exact middle per-se, but actually getting in side it somewhere in the first place. and the best way to do that is ofcourse to shoot for the exact middle.

[happyjack27]

happyjack:

in your electron only simulation I am amazed at how spherical, i.e., not spiky, the inner core of electrons is. Yet it also seems to show bunching of electrons along the cusp lines (cube projected onto a sphere effect) or am I seeing things there? If this is a real physical feature it indicates there must some secondary effect causing the electrons trapped in the core to 'puff-out' into a perfect sphere (minimal surface shape), like a surface tension due to some global interaction of the particles/plasma.

my understanding is that we are seeing what is termed a "wiffleball" - a point where electric kinetic pressure balances magnetic pressure.

If the six-coil arrangement can achieve a near perfect sphere electron core it means there would be no need to go to higher-order coil arrangements. In fact, it then would be interesting to see if such a spherical core could be achieved by just two coils in opposition, i.e., the simplest technical arrangement, would be a huge win.

i tried two opposing magnets in the ion-electron hypothesis thread, both with same polarity and opposite polarity. doesn't work, with opposite polarity the magnetic pressure keeps the electrons from going towards the magnet, but meanwhile it eats away at it sending the electrons flying out the sides.

however, one can imagine if you then put a pair of opposing magnets on each axis, you can counteract this affect in all three dimensions.

and then what you have there is a wb-6!

re: no need for higher polyhedron. yeah, it looks like that to me. that might well be the case.

[icarus]

So is this a physical result, cold electrons (i.e. near zero K.E.) accumulating in the very center?

If so it would be huge, also explain why they form a near spherical core, low KE means they cannot push back on the magnetic field significantly but the charge distribution would obviously want to distribute very close to spherical. I.e., they can't go anywhere but they are as away far away from each other as possible, which is not all that far.

But how long would this cold electron core last in the presence of 100MW fusing ion collision events, which is supposedly taking place right in this region? Million Watt question?

[icarus]

happyjack:

my understanding is that we are seeing what is termed a "wiffleball"

I think the 'theory' as per Bussard and Nebel is for a hot electron wiffleball, the cold electron wiffleball that you have discovered is a much different animal occurring at a much smaller radius. A singular entity to be sure but was there waiting to be found I have thought, I've seen similar same structures occur in analogous fluid flow experiments, it is due to the global spherical symmetry but only revealed when higher order effects are taken into account.

EDIT: time for someone else to play devil's advocate here, I'm in danger of slipping into confirmation bias mode.

[happyjack27]

But how long would this cold electron core last in the presence of 100MW fusing ion collision events, which is supposedly taking place right in this region? Million Watt question?

not sure. their mag fields would be proportional to their speed, but the time a particle spends at any relevant distance from their mag field would be inversely proportional to that, so it seems that that would effectively be no change. e-field you could argue that it doesn't increase with speed, but exposure time is likewise inverse to speed so it's affect would actual diminish. however, at higher speeds it will be able to get closer to other particle because the other particles won't have as much time to accelerate away, so in that case i don't know. also curious how the mag fields would react to such disturbances. would it counteract them?

i'm def. not at the point of building that in to the sim. in reality at the densities and time scales i'm running on i don't think i'd get a fusion event for weeks, anyways. i'd have to "force" one. ("ok, you two fuse. thank you.") and if i did i'm not sure i have the time resolution to model the resultant KE accurately. i'd have to drop it down. certainly within the realm of possibility. but not there yet.

[icarus]

happyjack:

yeah, I realise the limitations on 'simulatability'.

Have you thought about just starting with a ball of stationary electrons in the center and seeing if they remain spherically distributed and relatively stationary (cold) over 'longer' timescales?

Probably pretty boring sim. but worth doing as a stake in the ground if this is a physical discovery. Also, getting the result for the stationary radius of such a cold electron sphere, given mag. field, drive voltage would be worthwhile.

[happyjack27]

happyjack:

yeah, I realise the limitations on 'simulatability'.

Have you thought about just starting with a ball of stationary electrons in the center and seeing if they remain spherically distributed and relatively stationary (cold) over 'longer' timescales?

Probably pretty boring sim. but worth doing as a stake in the ground if this is a physical discovery. Also, getting the result for the stationary radius of such a cold electron sphere, given mag. field, drive voltage would be worthwhile.

you're actually describing my first couple sims there. yeah, they form a WB beautifully, but it's much spikier, as one would expect.

i just hope it's not some artifact from a faulty pseudo-random number generator.

[happyjack27]

come to think of it i think i had the e-fields off in those sims. so that could explain the discrepancy.

[TallDave]

you can see the electrons are much denser in the center, and given how they accumulated, that can only imply that their lifetimes are much longer.

Accumulation at the center will happen naturally, because it's where they're slowest. That's why there's a virtual cathode.

so really how many electrons do you want to pump in to the system?

Enough to replace the ones that thermalize.

i thought electron losses where the biggest problem.

Not really, PWs are e-driven by design. Excess electron losses would be a problem.

Electrons in the middle will head down their potential hill, and then they're going to bounce around randomly and thermalize. You might increase their confinement time by aiming for the middle (which is why I say it's interesting), but again I think aiming for the center means your well potential is dropping over time.

Why does the electron distribution have to be "non-thermal" (you mean non-Maxwellian right) again?

I'll let Rick answer that:

The idea behind inertial electrostatic confinement is that you inject electrons with directed (radial) energy into the system. These electrons then form a virtual cathode by giving up their kinectic energy to potential energy in the virtual cathode (hence the importance of inertia). You don’t want thermal electrons. Eventually electrons will thermalize and slow down. When that happens they accumulate around coil cases resulting in screening and other things you don’t want. That’s why you need to either cycle electrons through the system, or find a way to add radial energy to them. This is fundamental.

[TallDave]

as you'd rather have me put it much more awkwardly -- err... i don't even want to try that one -- an electron wb and an ion wb. now they are both formed by a balance between electric kinetic pressure and magnetic pressure. but since the ions are much heavier, that balance point is much further out (i.e. much in favor of electric kinetic pressure, relative to the electrons) so now you have two concentric cores, at different radii and of opposite polarity.

Ah, I see why you have two WBs. But I'm 99.9% certain you're only supposed to have an electron WB.

The ions should be confined by the electrons, not by the magnetic field. But it makes sense you would get that without the e-field on. Had me worried there

[icarus]

come to think of it i think i had the e-fields off in those sims. so that could explain the discrepancy.

OK. I suggest that as a baseline simulation, do the following;

- put in as many electrons as the sim. can handle
- start them stationary randomly distributed on a sphere of about the same size of what you have just found with you long-run cold sphere (assume e-guns can get them in there for now, i.e. no e-guns)
- use same mag, field, e-field conditions as the long run (what were those btw?)
- examine output for stationary (stable) cold electron sphere, measure radius

If you can show a stable or stationary cold sphere of electrons for any conditions it is a good result and you should try to everything you can to verify it and make that result more solid before doing anything else.

[happyjack27]

I'll let Rick answer that:

The idea behind inertial electrostatic confinement is that you inject electrons with directed (radial) energy into the system. These electrons then form a virtual cathode by giving up their kinectic energy to potential energy in the virtual cathode (hence the importance of inertia). You don’t want thermal electrons. Eventually electrons will thermalize and slow down. When that happens they accumulate around coil cases resulting in screening and other things you don’t want. That’s why you need to either cycle electrons through the system, or find a way to add radial energy to them. This is fundamental.

i see, so that lighter cloud of electrons outside the dense center but usually a fair distance away from the coils (as shown in the video i posted) is something you don't want because it dulls the potential well depth. so those are the thermal ones that you want out.

so you shoot an electron into the wiffleball and hope it pops one out of the outer cloud without popping one out of the wiffleball into the outer cloud nearly as quickly. in that case you still need the right energy range and good aim to get it to stick in the WB instead of just adding to the electron cloud.

[icarus]

Talldave:

I'll let Rick answer that:

He doesn't say anything about cold 'thermalized' electrons accumulating in the center of the machine only near the MaGrid, different question so no he didn't answer that.

[TallDave]

the limitations on 'simulatability'.

Heh, I'll just throw this out there for fun:

3-D Particle-in-cell is extremely expensive. Resolution goes like (N)**.5 where N is the number of particles. You have multiple timescales and multiple spatial scales to resolve. This means supercomputers.

He also said they'd be doing a lot of simulation over these couple years since. Sure would like to see those someday.

[TallDave]

Talldave:

I'll let Rick answer that:

He doesn't say anything about cold 'thermalized' electrons accumulating in the center of the machine only near the MaGrid, different question so no he didn't answer that.

Again, it's the top of their hill. They do not sit there, it's just their average position. They are going to come down, they are going to thermalize.