American Magnetics CRYOGEN FREE SUPERCONDUCTING MAGNET SYSTEMS - Manual

CRYOGEN FREE SUPERCONDUCTING MAGNET SYSTEMS
Cryogen-free superconducting magnets have become increasingly popular in research and indus-
try due to their ease and simplicity of operation as compared to traditional liquid helium cooled
magnet systems. These magnets are manufactured in a variety of confi gurations and sizes to
accommodate requirements of most imaginative scientists or engineers. Cryogen free magnet
systems use a closed cycle helium refrigerator to cool the cryogenic assemblies to temperatures
close to 4K. In certain confi gurations the magnet is conductively cooled in a vacuum whereas
some geometries use traditional LHe cooling with a cryocooler to recondense liquid Helium;
thereby resulting in near zero loss system (ReCon
TM ). Based on customer’s experimental re-
quirements either a Gifford-McMahon or a pulse tube cryocooler is used. Some of the most
widely used types of cryogen free magnet systems are listed and discussed below.
Room Temperature Bore (RTB) Solenoid Systems (Vertical or Horizontal geometry) •
RTB Radial Access Magnet Systems (Magneto-Optic systems) •
RTB MAxes • TM Multi-axis Magnet systems
Variable Field Variable Temperature (VFVT) magnet systems •
ReCon • TM style systems
Room Temperature Bore Solenoid Systems
These style systems are available in wide
range of bore sizes and fi elds up to 15T and
are designed in both horizontal and vertical
geometries. The thermal mass is cooled by
a Gifford-McMahon or a pulse tube cryo-
cooler depending on the individual applica-
tion. Pulse tube based cryocooled systems
are recommended for applications that might
have concerns with vibrations, however they
have higher initial costs but lower long
term maintenance costs. In case of pulse tube
confi guration, it is possible to reduce vibration
levels even further by adding bellows assem-
bly and positioning motor remotely. Some of
the most common applications include mate-
rial processing, beam line studies or use with
existing sample inserts . Materials process-
ing customers have found this geometry very
suitable for annealing samples in presence of
magnetic fi eld.
Pulse tube based RT bore system