1.5 T whole-body superconducting MRI system with a conduction cooling design

Motivation: Currently, helium-cooled superconducting MRI systems are expensive to operate, limiting their accessibility. Goal(s): Develop a helium-free whole-body superconducting magnet that reduces manufacturing and operational costs, increasing accessibility and promoting the widespread adoption of MRI diagnostics. Approach: Design, construct, test and evaluate a completely liquid helium-free 1.5T superconducting magnet. The new design employs the conduction cooling technology with a double-stage 418D GM cryocooler to achieve operating temperatures around 4.2K. Results: The magnet is shimmed to achieve RMS field inhomogeneity of 4.3ppm over 450mm DSV, with a field stability of 3*10-8/h. The conduction-cooled magnet operates with a steady temperature below 4.2K, producing high-quality human images. Impact: The developed conduction-cooled superconducting magnet technology will significantly impact the industry and broaden MRI applications.