Details

Autor(en) / Beteiligte

• Giebeler, F
• Thummes, G
• Best, K-J

Titel

A 5 T persistent current niobium–titanium magnet with a 4 K pulse tube cryocooler

Ist Teil von

• Superconductor science & technology, 2004-05, Vol.17 (5), p.S135-S139

Ort / Verlag

IOP Publishing

Erscheinungsjahr

2004

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We report on the design and testing of a cryogen-free superconducting magnet that is conductively cooled by means of a two-stage pulse tube cryocooler (PTC). The cooler provides a cooling power of 0.4 W at 4.2 K, when operated on a helium compressor with a nominal input power of 6 kW. The 5 T NbTi magnet is equipped with a persistent current switch with a resistive heater. The thermal coupling between the switch and the 4 K stage is chosen so as to allow operation of the switch without a marked heat input to the 4 K stage during the charging process. The PTC is capable of cooling the complete magnet system to a stationary temperature of 2.7 K, which was found to be stable for a period of more than two months. The magnet was charged to a field of 5.5 T, and persistent mode operation was monitored successfully for a period of three weeks.