A calculated 62,000 times increase in density vs ITER with 10 T magnets. ITER is using 20 T magnets.
Actually, I think the 6 in 62500 was a typo. Based on his numbers in that post, it looks like he meant 2500 (unless I'm missing something). Still very impressive, though.
As he points out, that's even without ion focussing.
I did a quick in my head and Nebel's number seemed OK. But even a 2,500X increase in density is excellent.
Hmmm, now I think that was my mistake and that the difference in ion density is squared to get the power density change (250 ^ 2 = 62500). I probably just missed the change in which density he was talking about.
What you will find is that the average density of ITER is ~ 1.0e20/m**3. If you use the formula I sent you for the Polywell, you will get a density ~ 2.5e22/m**3.
That's 250, not 2500. Apparently my own density was the problem.
TallDave wrote:Unlike a tokamak, there isn't a plasma-generated B field.
The only way I can think of that the plasma inside the machine deform the coils B-field to make a wiffle-ball is by creating its own field.
That is, the magnetic w-b would be the result of the interaction of the coils generated B-field and the plasma generated B-field.
Is there any other way I dont see?
Well, the electrons push back on the magnetic field because they want to get away from each other and kiss the positive Magrid. It's electron pressure, as I understand it.
There's a couple of ways to think about it. One is to look at the electrons spinning around the B field lines (they gyro part in gyroradius) and in the process they create a B field in the opposite direction to the external field.
(If they didn't we could build perpetual motion machines.)
When enough electrons and ions are spinning around the external B field lines you get a reduction in the total field. That causes the gyroradius to grow, which allows the external field to take over again. So there is a constant balance.
The higher the pressure, the more ions and electrons there are OR the faster they are moving, or both. The net end effect is that the B field is reduced.
You can call it "pushing" on the B field, because that is what it looks like.
drmike wrote:When enough electrons and ions are spinning around the external B field lines you get a reduction in the total field. That causes the gyroradius to grow, which allows the external field to take over again. So there is a constant balance.
The higher the pressure, the more ions and electrons there are OR the faster they are moving, or both. The net end effect is that the B field is reduced.
The B field is reduced inside the electron gyroradius but increased outside it, so the macroscopic field is lessened inside plasma's high density regions, and increased outside them. Right?
Superposition applies - the fields from the electron currents add to the external fields (generated by other currents...) So yes, since it's a dipole it'd have to. It would look like
the B field is being pushed back towards the MaGrid coils if there is enough current
flowing.