Stabilization of the burn in ETF

In ETF it is desired to maintain burn parameters of anti T/sub i/ approx. = to 12 keV, anti n/sub H/ approx. = to 1020/m3, P/sub n/ approx. = to to 1100 MW constant over a period nominally of about 500 sec. This clearly will require some feedback control mechanism since, left to its own, the equilibrium operating-point temperature would rise to an unacceptably high value thus leading to unstable values to β, large synchrotron emission, and a rapid buildup to He ash. It has been proposed that the burn may be effectively controlled by adding ripple to the confining toroidal field. In this note we investigate this possibility coupled with maintaining the density with pellet injection