Superconductors and Current capacity
Posted: Sat Feb 26, 2011 11:18 pm
I have seen magnetic field limits on superconductors, especially high temperature superconductors, but had not appreciated the corresponding current limits (B field =amp turns)
This link shows a new design that may be a step in the right direction.
http://www.technologyreview.com/energy/32424/?p1=A5
In WB 6 (ignoring cooling concerns) this new superconducter cable (~ 8 mm wide with a capacity of ~ 3000 Amps) could fit ~ 30 windings into the ~ 5 cm minor diameter of the WB6 magrid.
This would yield ~ 3000 A * 30 windings = ~ 90,000 amp-turns. This compares to perhaps ~ 400,000 amp-turns in WB6. So this high temperature superconductor could provide a maximum of ~ 200G, or ~ 50 G if you assume a 40% packing fraction.
A large Polywell with a major diameter of 3 meters and a fat diameter of 1 meter would allow for ~ 14,000 windings maximum, or ~ 6,000 windings if you assume a 40% packing fraction.
Number of windings in large machine =14,000 / 30 windings in WB6 size machine = ~ 450 X gain. For a 40% packing fraction that would be ~ 180 X gain.
Multiply 200 G by these gains gives maximum performance of ~ 90,000 G or ~ 9 Tesla maximum, and a more realistic 3.6 T for a 40% packing fraction.
This high temperature superconductor is not quite there, but it is getting close.
I assume the current/ B field limits per cable is proportional to the limits on a bundle of these cables.
Dan Tibbets
This link shows a new design that may be a step in the right direction.
http://www.technologyreview.com/energy/32424/?p1=A5
In WB 6 (ignoring cooling concerns) this new superconducter cable (~ 8 mm wide with a capacity of ~ 3000 Amps) could fit ~ 30 windings into the ~ 5 cm minor diameter of the WB6 magrid.
This would yield ~ 3000 A * 30 windings = ~ 90,000 amp-turns. This compares to perhaps ~ 400,000 amp-turns in WB6. So this high temperature superconductor could provide a maximum of ~ 200G, or ~ 50 G if you assume a 40% packing fraction.
A large Polywell with a major diameter of 3 meters and a fat diameter of 1 meter would allow for ~ 14,000 windings maximum, or ~ 6,000 windings if you assume a 40% packing fraction.
Number of windings in large machine =14,000 / 30 windings in WB6 size machine = ~ 450 X gain. For a 40% packing fraction that would be ~ 180 X gain.
Multiply 200 G by these gains gives maximum performance of ~ 90,000 G or ~ 9 Tesla maximum, and a more realistic 3.6 T for a 40% packing fraction.
This high temperature superconductor is not quite there, but it is getting close.
I assume the current/ B field limits per cable is proportional to the limits on a bundle of these cables.
Dan Tibbets