What would happen if Alternating Current ran in the rings?
What would happen if Alternating Current ran in the rings?
I have a feeling this will be one of those ideas which looks great on paper, but terrible in practice. A friend suggested it and I wanted to know what people thought about it. If an AC current went through the rings, it would continually flip the direction of the magnetic field. My thinking is, that during the “flipping” the fields would be zero and in that time the trapped material would dissipate. The flipping of the field should cause electrons to reverse motion. Those corkscrewing away from the center would head back into the center and vice-versa. The thing to get at is how much time all this takes. If the electron motion is ~3E7 M/S and the ion motion is 4.9E5 M/S and the distance is 6”, I would not expect that there is an alternating current on a time scale fast enough to effect particle motion.
Alternating current through the magnet coils? If the frequency is 500 HTZ, the B field would go to zero every millisecond. An electron travels ~ 10,000 M / millisecond, so during the fraction of a millisecond when the B field is near zero, the electron will escape. Admittedly the electron confinement time in WB6 was only ~ 0.2 milliseconds, but this ignores recirculation which changes the effective confinement time into a few milliseconds. Even at frequencies of 1 million HTZ, the electron travels 10 meters/ micro second or more. In a 3 meter machine the containment is again close to zero. At a frequency of a billion HTZ things might atart getting interesting.
Practically, alternating current or even variable D/C current may lead to magnet failure quickly. Each time the current changes, there are different expansion forces between the wires. The wires rub against each other and the insulation may quickly fail. Other issues like hysteresis may also cause problems.
If you wish to induce local variation in the plasma microwave input may be more appropriate (POPS). Alterations in the B field strength might also be useful if the magnets survive. This would be a variable D/C current, not an A/C current (does not pass though zero ). Combined with POPS induced plasma clumping, interesting things might happen. At very high frequencies the reversing field may cause charged particles to vibrate on a field line without migrating much in either direction. What effect this would have on cusp behavior, recirculation, bouncing, etc is uncertain, but I suspect harmful.
One mistake about magnetic containment in a Polywell would be comparing it directly to a Tokamak. There are definite limits on how long the B field can be maintained in a Tokamak. Also, in a tokamak magnetic field variation may be a tool to aid in the extraction of the fusion ash. In a Polywell the fusion ash (He3 and tritium ions from D-D fusion or alphas from P-B11 fusion) leave the system relatively quickly and naturally through the cusps, which a Tokamak does not have. Also, keep in mind that the plasma in a Tokamak is magnatized , while in a Polywell (within the Wiffleball) it is almost entirely non magnetized.
Dan Tibbets
Practically, alternating current or even variable D/C current may lead to magnet failure quickly. Each time the current changes, there are different expansion forces between the wires. The wires rub against each other and the insulation may quickly fail. Other issues like hysteresis may also cause problems.
If you wish to induce local variation in the plasma microwave input may be more appropriate (POPS). Alterations in the B field strength might also be useful if the magnets survive. This would be a variable D/C current, not an A/C current (does not pass though zero ). Combined with POPS induced plasma clumping, interesting things might happen. At very high frequencies the reversing field may cause charged particles to vibrate on a field line without migrating much in either direction. What effect this would have on cusp behavior, recirculation, bouncing, etc is uncertain, but I suspect harmful.
One mistake about magnetic containment in a Polywell would be comparing it directly to a Tokamak. There are definite limits on how long the B field can be maintained in a Tokamak. Also, in a tokamak magnetic field variation may be a tool to aid in the extraction of the fusion ash. In a Polywell the fusion ash (He3 and tritium ions from D-D fusion or alphas from P-B11 fusion) leave the system relatively quickly and naturally through the cusps, which a Tokamak does not have. Also, keep in mind that the plasma in a Tokamak is magnatized , while in a Polywell (within the Wiffleball) it is almost entirely non magnetized.
Dan Tibbets
Last edited by D Tibbets on Sun Dec 02, 2012 12:36 am, edited 1 time in total.
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happyjack27
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agreed.
ac on coils = fail. for two reasons:
*the physical stress that produces is a problem
*timescales of electrons are jsut way too small compared to ac current.
if you want ac effect, the thing to do to avoid both of those problems is use electromagnetic waves instead - e.g. in the range of microwaves to affect the electrons or r.f. waves to affect the ions.
though none of this considers the electric current created by a changing magnetic field. (as in an electric generator.) that could be interesting. but i suspect the difference in timescales might still be overwhelming.
ac on coils = fail. for two reasons:
*the physical stress that produces is a problem
*timescales of electrons are jsut way too small compared to ac current.
if you want ac effect, the thing to do to avoid both of those problems is use electromagnetic waves instead - e.g. in the range of microwaves to affect the electrons or r.f. waves to affect the ions.
though none of this considers the electric current created by a changing magnetic field. (as in an electric generator.) that could be interesting. but i suspect the difference in timescales might still be overwhelming.
Also agreed.
Capacitive reactance varies as 1/f and inductive reactance varies as f, so the impedance (RLC) of the magrid coils to an AC signal would be dominated by inductive reactance as frequency goes up, tending towards an open circuit in the limit.
To explore high frequency modulation, better to vary the magrid case potential and leave magnet current constant. Or use microwaves.
Capacitive reactance varies as 1/f and inductive reactance varies as f, so the impedance (RLC) of the magrid coils to an AC signal would be dominated by inductive reactance as frequency goes up, tending towards an open circuit in the limit.
To explore high frequency modulation, better to vary the magrid case potential and leave magnet current constant. Or use microwaves.
Like, they did. (ECF). Read past reports/public accessible stuff.Or use microwaves
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)