Marcus,
Here's what I found out so far. To recap what's written below is use two copper tubing coils (2 turns each) in helmholtz configuration where their distance apart is equal to the radius of the tube coils. A high voltage pulsing circuit, pulses one coil and then the other microseconds later so that the magnetic field changes direction each time the control circuitry pulses the coil.
Take a look at the following.
Thanks,
Bob
A second very promising approach is also being pursued. Since work began on the high Q tank circuits,
IGBTs (very high current on-off solid state switches) have become available that can each switch 3000 A at
1500 V at 0.5 MHz for a several hundred microsecond pulse. Two power supplies are presently under
construction that will each use twelve IGBT’s in parallel. Figure 4 shows the circuit schematic.
Here’s our power supply, suggest using two copper tube coils (2 turns) in helmoltz configuration and this circuit would pulse each of the copper tube coils. Helmoltz configuration means both coils are separated by the radius of the copper tube coil.
The IGBT output
will pass through a 20:1 air core transformer and into a parallel LC tank circuit (Q~100), where the inductor is
the RMF antenna. By presenting a high impedance only to its resonant frequency, the tank circuit transforms
the output waveform of the IGBT’s into a clean sinusoid. Additionally, the tank circuits high Q greatly amplifies
the real power delivered with circulating power, enabling the creation of a .01T RMF. With a low total
inductance of ~20nH in the primary side of the circuit, as the plasma load increases, the IGBT’s should be able
to provide the current necessary to sustain the secondary voltage, and hence maintain a constant RMF. For
Radius =
0.36 m Width =
0.6m
Separation = 0.36m
Quartz Tube
Radius = 0.2 m
Contours mark .001 T
increments of BRMF.
tens of microseconds, the maximum current output of 3000A can be exceeded by a factor of 5 to 10. The peak
output power may not be as high from the IGBTs as from the LC tank, but they have the advantage of both a
longer quasi-steady duration, and an easily variable frequency for experimentation.
FIGURE 4. IGBT Power Supply, Transformer, and RMF Parallel Resonant Circuit.