JET-P(97)40
Analysis and Tests in Support of Upgrading the JET Toroidal Field to 4 Tesla
Until 1997 the maximum toroidal field (B) of the JET machine was 3.4 Tesla. When B is raised from 3.4T to 4T, in-plane forces rise by 38% and, if the plasma configuration is unchanged, out-of-plane forces increase by 18%. To increase confidence in the ability of the coils to withstand higher fields after 14 years of operation, several new analyses and tests have been made. They include review of test data to set allowable stress and force limits, new detailed finite element models of critical parts of the coil, tests of mechanical strength and elastic properties of insulation systems of used coils and comparative mechanical tests of used and unused coils.