90-mm/18.8-T All-HTS Insert Magnet for 1.3 GHz LTS/HTS NMR Application: Magnet Design and Double-Pancake Coil Fabrication.

This paper deals with the latest design of an all High Temperature Superconductor (HTS) insert for our 1.3 GHz NMR program. Due to a loss of our original 600 MHz HTS insert, the entire program was revised, and upon further examination of the options available for the HTS insert, which included not only conductor material properties, but also new winding technologies recently developed here at the FBML, it has finally been decided to build an 800 MHz (H800) insert purely based in SuperPower YBCO conductor. The new H800 will still be comprised of nested stacks of double-pancake coils and will run in the background of a 500 MHz LTS NMR magnet already available at FBML. We present here electromagnetic and mechanical details of the H800 design, winding technique employed, and testing of individual coils.