Plasma disruption forces: a program for the HP 9845 and 9872 B plotter

A computer program is described for the calculation of currents, forces, torques, and voltages in the conducting first wall and limiter of a tokamak reactor experiencing a plasma quench. Instructions are given for running the program on a HP 9845 B desk-top computer with a 9872 B plotter. The first wall and limiter have been modelled by 44 coaxial loops. The inductance matrix among the loops is calculated, and the currents in them are calculated step-by-step over time, driven by the flux from the decaying plasma current and subject to the field from the plasma, from the poloidal field coils, and from all current loops. An insulating break in the limiter or first wall can be modelled by imposing a back voltage which causes all the currents in the limiter or first wall to sum to zero. This potential is related to the voltage between segments of a segmented limiter or first wall