A model for correlating 4.2hyphen;K performance with roomhyphen;temperature mechanical characteristics in superconducting test dipole magnets for the Superconducting Super Collider (SSC)

摘要

The longitudinal attenuation of impacthyphen;generated pulses in ten superconducting dipole magnets was measured at room temperature. A lumpedhyphen;parameter model was constructed for the collared dipole. Using the method of nonlinear leasthyphen;squares, the model was used to estimate the internal damping in the main components of the dipoles and the coupling resistances between the components: collars, inner, and outer coils. A positive correlation was found between the collarhyphen;inner coil coupling resistance and the 4.2hyphen;K performance of the magnets: the higher the coupling resistance, the fewer the number of quenches required to reach design operating current. There was virtually no correlation between any of the other internal or coupling resistances and 4.2hyphen;K performance. These observations are explained in terms of frictional slip of the inner coil against the collars causing premature quenches. The magnets are more susceptible to quenches at the collarhyphen;inner coil interface than at the collarhyphen;outer coil interface because the inner coil is subject to higher fields and forces. The experiment is potentially useful as a technique for screening highhyphen;performance superconducting magnets such as Superconducting Super Collider (SSC) dipoles at room temperature.