We present here an innovative approach, for design and construction of high-field HTS NMR magnets, No Insulation (NI) HTS winding with bare or reduced-stabilizer 2G conductor that completely eliminates turn-to-turn insulation. In this two-year program we will focus on two specific aims: 1) to design, construct, and test a standard 54-mm warm bore 7-T (300 MHz) HTS NI magnet in order to demonstrate feasibility of the proposed NI technique for actual NMR-size magnets;and 2) to generate a combined field of 14 T with the 300-MHz 2G NI magnet and a 300-MHz LTS background NMR magnet currently available at MIT Francis Bitter Magnet Laboratory. Success of this combined 14-T magnet will validate the technical viability of NI magnets for high-field (GHz-class) LTS/HTS NMR applications. Since the compact NI winding essentially removes soft turn-to-turn insulators and minimizes stabilizer thickness of the 2G HTS winding, it will enhance mechanical integrity and enable more reliable operation of HTS magnets with self-protecting feature. Furthermore, an NI magnet with its dimensionally least precise component eliminated from its winding, and thus its manufacturing errors reduced, will have a spatial field homogeneity inherently much better than its insulated counterpart. Equally important, because HTS itself has a thickness comparable to a typical insulation thickness, the overall size of an NI HTS magnet can be significantly reduced, leading to reduction in size and cost of a high-field LTS/HTS NMR magnet system. Considering that the price of an NMR magnet is one of the decisive factors in capital investment for most laboratories, we believe that less expensive NMR magnets derived from the NI HTS magnet technology will have a huge impact on the high-field NMR magnet industry. Success of this program will demonstrate elegant and practical solutions to mechanical, stability, and protection issues fundamental to LTS/HTS NMR magnets. More generally, the NI technique will benefit most applications relying on DC HTS magnets that are compact, mechanically robust, stable (reliable), protected, and competitive in price.
This innovative 7-tesla/54-mm bore no-insulation HTS magnet research will greatly benefit high field HTS NMR magnet developments in the world, as it enables new HTS magnets to be much more compact, stable, stronger, and most importantly less expensive than conventional magnets.