An integral criterion of ignition in the inhomogeneous plasma of a tor
oidal reactor is obtained. The possibility of using this criterion for
burn control in a reactor operating near ignition with a high energy
gain is demonstrated by means of numerical modeling. The existence of
an ignition scenario with decreasing temperature before ignition is de
monstrated and explained. It is shown that a temperature profile near
the unstable steady-state profile can be achieved by the appropriate c
hoice of auxiliary heating characteristics. A method of continuous ope
ration, based on weak modulation of the heating power, is proposed.