Superconducting magnets

Superconducting magnets consist of solenoids made of superconducting, Nb-Sn, Nb-Zr or Nb-Ti wires kept at liquid helium temperature. Hence, the solenoid must be inserted and maintained in a liquid-helium dewar Liquid helium must be continuously supplied to keep the system at 4.2 K. Laboratories that use superconducting magnets must acquire, or produce, liquid helium. With such a purpose some companies commercialise medium to small capacity liquid helium liquefiers.

Some superconducting solenoids can be also designed to operate using closed-cycle liquid helium refrigerators. Otherwise liquid helium must be periodically buy. The magnetic field is produced in the axial cylindrical bore of the coil. Currently, superconducting solenoids that produce magnetic fields in the range 5-18 Tesla are commercially available.

Superconducting magnet power supply. To operate a superconducting magnet requires an appropriate bipolar power supply (it has the ability to set either positive or negative current and voltage values). Therefore, each electromagnet model is offered with its corresponding programmable power supply. The electromagnet power supply delivers a high stability and low ripple current. Its most important output parameters are: maximum current and voltage, stability, ripple an noise and temperature coefficient.