Evaluation of APC NbTi superconductor in a model dipole magnet

Abstract

A b s f r a c t -The artificial pinning center (APC) approach to NbTi superconductor fabrication offers the potential benefits of higher current density and lower cost than the conventional process for NbTi, We have been evaluating several approaches for fabricating NbTi via the A P C approach t o determine whether these advantages can be realized in a practical conductor. The study began with the fabrication by several vendors of lOkg size samples which were evaluated a s short samples. This was followed by the scale-up of one process to 150" diameter billets. This material was evaluated first in a solenoid configuration and recently in a one-meter long dipole. We will report here on the results of these coil tests and other characterization results for this new material. We will also describe the plans to continue the scale-up to full size billets and we will discuss the potential cost savings of this approach compared with conventional NbTi fabrication.

First commercial application of NbTi superconductor employing artificial pinning centers

“…The higher current density available from APC superconductors will allow this trend to continue. In addition some cost modeling suggests that APC processing is less expensive than conventional melt based alloying [ 5 ] .…”

Niobium based intermetallics as a source of high-current/high magnetic field superconductors

“…Such semi-finish product has to be upgraded by introduction of Al or Sn alloys for the reactive diffusion formation of the intermetallic phase in the case of A15 intermetallic superconductors, or/and by introduction of the Artificial Pinning Centres as in the case of NbTi. However attractive, all three existing APC techniques require very expensive metal alloy rods and extensive cold working processes from very large diameters [25][26][27]. Infiltration of the presintered alloy rod or plate such as Nb-Ti-X or Nb-Al-Ge-Z by Al [28] or Al alloy material, where X or Z represents addition metals has its advantages because for example recently NbTiTa ternary alloys have been explored as a high field avenue for APC materials.…”

High energy physics conductor scale-up progress of the Supercon artificial pinning center process

“…The Supercon APC process has been proven to yield composites with commercially attractive high field current density (Jc), excellent piece length, and has been successfully incorporated into laboratory solenoid and dipole magnets [7,8] Commercially available Supercon APC material has superior performance compared to conventional NbTi for applications I 5T, is lower in production cost, and has been successfully incorporated into MRI magnets [9].…”