Superconducting scanner magnet for much lower cost, compact proton therapy systems

Solid Material Solutions, LLC (SMS) SBIR Phase 1 ABSTRACT NIH FOA PA-21-259Proposal Title: Superconducting scanner magnet for much lower cost compact proton therapy systemsProton Therapy (PT) is a proven, superior technique for treating cancer tumors compared to conventional X- ray therapy that can cause excessive healthy tissue damage. Yet it is available to less than 4% of the patients that would benefit from it, because for widespread usage, compact, much lower cost PT systems are required with much smaller magnets using High Temperature Superconductors (HTS) that generate higher fields at affordable operating conditions than current copper and Low Temperature Superconductor (LTS) magnets. Although PT system manufacturers have been developing more compact, lower cost PT systems, none have yet attained the combination of adequately low cost and reduced size to fit into much smaller treatment rooms, and full capabilities of the larger and costlier systems. It is specifically a key requirement for the PT system to fit into the small, low-cost treatment rooms that are already well established for low-cost X-Ray treatment.An essential component for the development of this ultra-compact, low-cost PT system is a much shorter HTS scanner magnet. This program will now develop a sufficiently short scanner magnet that recently became attainable due to breakthrough advances with the HTS-2212 material at Solid Material Solutions on wires, cables and coils for fast-ramp usage where inductive losses require advanced, low-loss conductor of the type required for this application.The specific product objective is a 4-coil scanner magnet that is one third the length of present magnets. It will include conduction cooling pathways, a cryo-envelope, current leads and control sensors. It will be readily plugged into the ultra-low-cost PT system and deliver the same performance as present magnets while also consuming 1/10th the electrical power.The Phase 1 program is aimed at establishing a specific 2212-based cable design and validating its production, along with design and fabrication of a low-loss demonstration coil with required radial build, current (Ic), and current density (Je) at the affordable cooling temperature regime of rt 20K. This will be achieved by 1) Establishing specific wire and cable designs along with validation of their fabricability and properties 2) Developing specific capability to wind these cables into racetrack coil modules of the target radial build, overall shorter dimensions and with the required current and current densities to attain 2T at temperatures of 20 K or greater, and 3) Developing capability to fabricate coils of the target axial length from the racetrack modules, along with mechanical fixtures, current leads and voltage taps, followed by validation of its capability to generate the target 2 T at rt 20 K in the dipole coil gap where the proton beam would be deflected.These developments will provide basis and justification for completing in a subsequent Phase II program, the commercial design, development and qualification of a full scale, conduction cooled coil set and magnet system that meets all requirements. When fully developed, this plug-in shorter scanner magnet will enable compact PT systems to be retro-fit height-wise into widely used treatment rooms of the kinds used for X-Ray therapy.