Penetration of Time-Varying Vertical and Horizontal Magnetic Fields through a Resistive Shell in a Tokamak Apparatus

Abstract

The magnetic field penetrating through a model resistive shell 1/5 times the size of the resistive shell of the JIPP T-II apparatus is measured. The sinusoidal component of the field inside the shell is reduced to 40% of its. D.C. value and made out of phase by 70° at a frequency of about 1.2 kHz corresponding to the skin time of the shell. The major radius distribution of the field is scarcely effected by the shell. The time evolution of an impulse-like vertical field inside the shell is evaluated the experimental results. The time constant of the rise of the vertical field is estimated for a unit step current.