End effects in the NHMFL 45 T hybrid resistive insert

Design evolutions of the resistive insert of the Hybrid magnet at the National High Magnetic Field Laboratory (NHMFL) have been ongoing based not only on the mid-plane stress state but the effects of the individual coil end-turns. The end-turns inherently have an unconstrained free edge that places additional bending on the Florida-Bitter discs. Finite element analysis of the Hybrid resistive insert has been performed and the results focusing on the end-turns are presented along with a description of the analytical procedure. Numerical results are supported by operational experience. Past, present, and future resistive insert designs are analyzed showing successful operation of the insert to 110% of the original design current.