MRI COOL DOWN APPARATUS

摘要

A means and a method to cool down an MRI magnet, in a cryostat that is designed for a maximum pressure of about 0.2 MPa, are described which use cold helium output from a Brayton cycle refrigerator at a pressure of about 0.8 MPa to exchange heat with helium in the MRI cryostat in a coupling heat exchanger that is located removeably in or proximate the neck tube of the MRI cryostat. A circulator drives helium from the MRI cryostat through the coupling heat exchanger.

主权项

1. An apparatus for cooling down an object to cryogenic temperatures comprising;
a Brayton cycle refrigerator which outputs a first stream of cold helium at a first pressure, a refrigerator cryostat which houses the cold components of said refrigerator, a coupling heat exchanger which transfers heat from a second stream of helium at a second pressure to said first stream, a circulator which circulates said second stream through an object cryostat containing the object being cooled; said coupling heat exchanger and circulator being proximate to said object cryostat.