A cryogen-free open superconducting magnet for interventional MRI applications

High-Field Superconducting Magnets

“…Cryogen-free cryostats in which all heat loads are removed by a cryocooler have been an important field for developments since the middle of 1990 (Steinmeyer et al 2002;Ackermann et al 1999;Razeti et al 2008;Laskaris et al 1995). However, cryostats using multiple cryogens also are a progressing field especially when looking at HTS (Stautner et al 2009).…”

Lightweight, compact, and high‐performance 3T MR system for imaging the brain and extremities

“…To accommodate a head‐sized gradient coil with good linearity over a 26‐cm diameter spherical volume (DSV), the C3T magnet has a warm‐bore inner diameter of 62 cm. The use of conventional superconducting NbTi wire facilitates operation at 4 K using a single 2‐stage 1.5‐W Gifford‐McMahon cryocooler (Model RDK‐415A3, Sumitomo Heavy Industries, Allentown, PA) to maintain the magnet coils at 4 K. This resulted in increasing the total stored energy by a factor of 3 as compared with the previous cryogen‐free interventional 0.5T MRI system . The magnet uses a standard 8‐coil design with 6 main coils and 2 shielding coils to contain the 5‐Gauss line within a 4 × 6 m area (Figure ).…”

Design and Optimization of Superconducting MRI Magnet Systems With Magnetic Materials

“…An operating coil temperature of approximately 12 K could be achieved using two double-stage Gifford-McMahon (GM) cryocooler subassemblies in a conduction-cooled split cryostat design similar to the designs detailed in [44] and [45]. Within a vacuum chamber that encompasses each of the magnet poles, a thermal screen that surrounds the superconducting coil arrangement would be thermally coupled to the first stage of a single GM cryocooler.…”