50 mm bore superconducting dipole with a unique iron yoke structure

摘要

A 50 mm bore superconducting dipole with a thin stainless steel collar and a close in elliptical iron yoke was designed in order to obtain a high transfer function SW low saturation effects on the multipoles, and a one meter model was built and tested. Training behavior of the first 1 m model, called D19, is presented at 4.3 K and 1.8 K. At 1.8 K it reached the record field of 10.06 T. The two layer cos (theta) winding uses 30 and 36 strand cables identical to the cables of the 50 mm bore SSC dipole and it has an operating field of 6.6 T at 4.35 K with a current of 5800 A. To evaluate behavior at high fields, the mechanical structure for the model was designed for 10 T. The thin collar itself provides only a minimum prestress of 10 MPa. and the full prestress of 70 MPa is given by the iron yoke. An aluminum spacer is used to control the gap size in the vertically split iron yoke. The tapered gap in the yoke is determined by the size of the Al spacer so that during cooldown there is no loss of coil prestress and the gap remains closed when the magnet is energized.