Lightweight 50 kG Superconducting Magnet System for Optical Research Instrumentation

Since the discovery of high field superconductors, it has been possible to generate high magnetic fields with lightweight, compact superconducting solenoids. In most cases, these magnets are operated in conventional liquid helium Dewars which are heavy and unwieldy and usually offer only vertical access to the magnetic field, which makes them very inconvenient for many uses, such as with optical research instrumentation. A system is described in which the magnet and cryostat are integrated into a single light weight package which weighs only 13.6 kg and provides horizontal access to magnetic fields in excess of 50 kG with working bores of 3.80 cm at temperatures near 4.2°K and 2.54 cm at room temperature for periods up to 12 h between fillings. Due to its over-all configuration, the magnetic field is highly accessible and allows spectroscopic measurements to be made conveniently at 50 kG. Also, the system can be easily transported while it is filled with liquid helium.