| 摘要 |
<p>When cooling a superconducting magnet for use in a magnetic resonance imaging (MRI) device, a two-stage cryocooler (42) employs a first stage cooler (52) to cool a working gas (e.g., Helium, Hydrogen, etc.) to approximately 25 K. The working gas moves through a tubing system by convection until the magnet (20) is at approximately 25K. Once the magnet (20) reaches 25 K, gas flow stops, and a second stage cooler (54) cools the magnet (20) further, to about 4 K.</p> |
