Anywhere that fields from SAME POLARITY coils meet.
Which is everywhere there is a side.
Where opposite polarities meet, they form on extended field.
They cancel at the center. You can't contain anything that way.
But not so well that they don't want to pay to move the nub, which seems is the prime stated purpose of this new contract.
Well, what it actually says is:
188.8.131.52. The review shall primarily investigate the effects of parallel electron heat loss to the coil joints with respect
to plasma stability and electron confinement time.
3.2.1 The contractor will modify/upgrade the existing wiffleball #7 (WB-7) device by installing compact, high
temperature coil joints to investigate the electron parallel heat loss. This modified device shall hereafter be
identified as Wiffleball #7.1 (WB-7.1).
That doesn't say they're moving them. I'd say it's an open question where they are and why. Maybe Rick will enlighten us at some point.
Not looking for a "square" field, just a substantial restriction in the size of the funny cusp.
At the expense of creating a nonconformal coil shape, meaning you're going to have electron flows going near or through your coils, which is much worse than cusp losses. Again, Bussard knew a lot about cusps, and didn't design it that way. In fact, he went to considerable effort to create conformal containers, and insisted future machines must have them. I would carefully review Bussard's statements before assuming what you're doing will improve on his design. He was a clever guy and spent two decades working on the concept through many iterations.
Robert Bussard wrote:...it was always known that conformal magnet coil
cans/casings were the only way to avoid B field intersect
with their surfaces, but since it was difficult and costly to
build such container shapes,
The need for magnetic field coil containing structures
to be conformal with the B fields they produce, to
avoid excessive electron impact losses (as above)
This requirement has two main consequences: (a) All
coil containers/casings must be of a shape conformal to the
B fields produced by their internal current conductors, and;
(b) The finite size of real coils forces design so that no
coils/containers can ever be allowed to touch each other, but
all corners MUST be spaced at some distance from the
adjacent coils, to avoid B field intercept.
This SHOULD restrict the external population of electrons which some insist is essential. (I think it desireable, but not essential)
Without the B field holding in the plasma, you will never get close to net power densities. Remember, power is B^4 R^3. With no wiffleball, there's no B^4 scaling. You'd need a truly gigantic reactor to get to 100MW on r^3 alone.