High magnetic field facility in Grenoble

The Grenoble High Magnetic Field Facility (GHMFL) is open to the international scientific community. It can produce steady magnetic fields on 3 magnet sites with a 24MW power supply and on 6 sites with 12 MW. One of the 24 MW sites is designed to reach 40T in a future hybrid arrangement. The two other sites give either 33T in a 34mm bore diameter or 29T in 50 mm. The GHMFL has developed the use of helix inserts made of copper alloy tubes cut by spark erosion. This technique allows making high field magnets with more stable mechanical and electrical behaviors than by the 'Bitter' technique. Based on this technique a 14 helix insert powered by 11 MW was developed. It was first tested in 2002 and is now in operation on one of our three 24 MW site giving access to 33 T. In parallel a 8 helix insert with enhanced homogeneity was developed taking advantage of the possibility offered by the helix technique to make a variable pitch along the main axis. It gives access to a field of 20 T in a 160 mm bore. In 2006, a new high field version of the 14 helix is under construction and expected to reach 34 T. This technology will also be used for the design of a magnet with homogeneity of the order of 10 ppm on a sphere of 1cm3 (with extra shimming). This magnet will be dedicated to high resolution NMR studies.