A Panofsky-Type Superconducting Quadrupole with a Very High Gradient Homogeneity

A Panofsky type superconducting quadrupole has been designed and built to be used on a spectrometer beam line at the synchrotron Saturne II. Its main characteristics are a large rectangular aperture (39.4 × 16.4 cm2 useful aperture), a gradient of 10 T/m on a magnetic length of 85 cm and a very high gradient homogeneity (??G/G?3.10-3 requested in the largest part of the useful aperture), for which several improvements from. the standard configuration have been necessary: coil end shape, iron shimming and possibility of overpowering some coils in the winding. The design, the construction, the electrical tests and magnetic measurement results obtained with this quadrupole are described in this paper.