THERMAL END LOSS FROM A PLUGGED THETA-PINCH

Thermal loss of energy from a theta pinch column is calculated, given zero flow at the ends and axial pressure balance. The solution models a theta pinch with end plugs. Te/Ti=1 is assumed, and only electron thermal conductivity parallel to the tube axis is considered. A closed analytic solution is obtained for the time and space dependence of temperature and density. The solution does not admit arbitrary initial conditions, but represents the long-term behavior of the plasma. Some implications for the problem of constructing end plugs are discussed.