A 30 Tesla - 20 MW magnet with a 50 mm bore was set into operation at the G
renoble High Magnetic Field Laboratory (GHMFL) in April 1998. It is made of
two 10 MW magnets. The inner magnet is composed of a series of 10 helices,
electrically in parallel with two thin Bitter coils connected in series. W
e give the specifications of this magnet and present the design of the 14 h
elix insert which is now under construction for a 34 mm bore magnet.