Estimation of internal magnetic flux in a compact torus

An attempt to estimate the value of possible spread of the internal flux values (psic) in a compact torus (CT) at the given (measured) values of the external flux and dynamic signal D=He-ψu/πR02, where He is the external field on the chamber wall, ψu is the opened (external) flux, R0 is the chamber radius, is made on the basis of two-dimensional calculations of equilibrium states. It is shown that during the adiabatic evolution of the CT equilibrium structure under different conditions in the wide range of ψu/ψc ratio the diamagnetic signal in the central torus cross section remains approximately proportional to a closed flux. It gives a possibility to estimate the closed flux in CT and its change with time according the diamagnetic signal. Connection between D and ψc differs considerably from the one proceeding from the simplified model of a ''long torus''