Vacuum conditions and edge current

It is proposed that the major contribution to a good clean vacuum system in producing a well-confined plasma in the toroidal fusion program is primarily the reduction of an edge current that also flows poloidally in and around the structures of tokamaks. The major contributor to the low-beta conditions of tokamaks is proposed to be this edge cross current. The loss of plasma energy by enhanced diffusion, charge exchange, and many of the other factors that are affected by the vacuum conditions can be attributed directly to the cross current. The author shows how a low edge cross current condition could produce the same results as a good vacuum condition and essentially equates the condition of a low edge cross current through the vacuum regions into the structures and a good vacuum for fusion program improvements. He then provides suggestions of how the cross current and good plasma conditions can be obtained more economically by controlling the cross current instead of providing the expensive near-perfect vacuum conditions and techniques that are now being utilized.<
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