Status of the SPARC Magnetic Diagnostics

In preparation for the impending arrival of the SPARC vacuum vessel, much of the internal magnetic diagnostics (MAGX) have already been wound and inventoried on site, including all 168 equilibrium B-field sensors (B_p, B_n) arranged in 4 toroidal sets. MAGX will also have 104 saddle flux loops (4 toroidal sets), 8 full flux loops, 8 sets of plasma current+diamagnetic sensors (4 in-vessel, 4 ex-vessel), 20 high frequency Mirnov sensors (arranged in 2 toroidal arrays), and 124 halo current sensors (108 Rogowskis and 16 B_T sensors). The MAGX attachment mechanisms and structural supports required extensive electromechanical analyses and design iteration in order to ensure that the sensors will survive the large disruption forces for the lifetime of SPARC, since in-vessel maintenance is not a viable option. Procedures for calibrating the MAGX sensors, primarily using a well-characterized Helmholtz coilset, are being developed and tested. Detailed mappings of the hundreds of signal leads to their respective vacuum port feedthroughs have been vetted to ensure there are no interferences with first wall structures or other diagnostics. By the time of this APS conference, we expect that installation of MAGX into SPARC will be underway.