A 15T cryogen free magnet system

Abstract We have constructed a number of superconducting magnets which are directly cooled by cryocoolers and can achieve fields up to 15 T at temperatures of about 4 K. No liquid helium is required. The magnets have bores in the range of 50–800 mm. The current to the magnet is in the range of 100–240 A. It is carried by HTS conductors from 50–4 K with resistive leads above this temperature. The bore can be at room temperature or a variable temperature sample space can be provided. Due to the exceptionally compact design there is very good access to the high-field region. The magnetic field can be orientated in any direction and the cryomagnet can even be rotated while in operation. A patented thermal buffer can be used to allow fast ramp rates to field.