Unlike the Tokamak design, in which the magnetic field must be narrowed to squeeze the hot plasma to greater density, in a dipole field the plasma naturally gets condensed, Kesner explains. Vibrations actually increase the density, whereas in a Tokamak any turbulence tends to spread out the hot plasma.
The renowned physicist Richard Feynman once compared confining a plasma inside the magnetic field in a Tokamak to "trying to hold Jell-O with rubber bands," says LDX chief experimentalist Darren Garnier of Columbia. "It's the difference between pulling and pushing." Whereas the Tokamak's magnetic field tries to push the plasma in from the outside, "we have the field lines on the inside, pulling on the plasma," which is inherently more stable, he says.
Engineering is the art of making what you want from what you can get at a profit.
IEC (Polywell) and "Levitated Dipole" are just the only two fusion reactors that I know which confine ions toward the center (as the Sun does). Pulling them from the inside. Maybe it is time to start mimic nature!!! It has always given great results. Going against nature is not impossible but it has demonstrated for long to be the hard way.
So is this system generating the intense pressure needed to fuse atoms (D-D or T-D) that I thought was requried in a tokamak design? I thought Polywell was getting around the pressure issue and replacing it with speed (smashing the atoms together at great speed). Is that true?
rj40 wrote:So is this system generating the intense pressure needed to fuse atoms (D-D or T-D) that I thought was requried in a tokamak design? I thought Polywell was getting around the pressure issue and replacing it with speed (smashing the atoms together at great speed). Is that true?
Not exactly.
Density (pressure) is higher inside the grid than outside. Dr. B called it the Whiffle ball multiplication factor.
Engineering is the art of making what you want from what you can get at a profit.
So the polywell has the Whiffle ball multiplication factor. Does this MIT design have something similar? Or, is it still closer to the bad ol' tokamak design?
As far as I know Tokamaks don´t use high pressures to fuse atoms. They use high temperatures in order to increase the kinetic energy of the ions ( # collisions) . Polywell, instead of using high temperatures , uses directly electromagnetic attraction toward the central well to enhance ion velocity and create more collisions.
Which is for you the more elegant and simpler way of confinement? I have clearly done my choice
jlumartinez wrote:As far as I know Tokamaks don´t use high pressures to fuse atoms. They use high temperatures in order to increase the kinetic energy of the ions ( # collisions) . Polywell, instead of using high temperatures , uses directly electromagnetic attraction toward the central well to enhance ion velocity and create more collisions.
Which is for you the more elegant and simpler way of confinement? I have clearly done my choice
Well, some designs use magnetic compression or "pressure" to increase density, which in turn creates higher temps.
A gas can be heated by sudden compression. In the same way, the temperature of a plasma is increased if it is compressed rapidly by increasing the confining magnetic field. In a tokamak system this compression is achieved simply by moving the plasma into a region of higher magnetic field (i.e., radially inward). Since plasma compression brings the ions closer together, the process has the additional benefit of facilitating attainment of the required density for a fusion reactor.