Production of tin core modified jelly roll cable for the MIT Multipurpose Coil

A report is given on the effort to produce 600 kg of tin core MJR (modified jellyroll) wire with a critical magnetization current density of greater than 800 A/mm² for 10 T, 4.2 K, 10- mu V/m operation while keeping the non-Cu cross section and at non-Cu loss rate at less than 460 kJ/m³ (+or-3 T cycle). The wire will be used in MPC (Multipurpose Coil) conductor modules as part of the US Demonstration Poloidal coil (US-DPC). The 18 subelement design provides three-micron-thick filaments to achieve a compromise between non-Cu loss and critical current density requirements. Vanadium diffusion barriers and titanium additions to the filaments are used to reduce loss and provide reaction flexibility.