Training Curves of Nb<sub>3</sub>Sn Rutherford Cables With a Wide Range of Impregnation Materials Measured in the BOX Facility
S. Otten, A. Kario, Wilhelm A.J. Wessel, J. Leferink, Herman H.J. ten Kate, Michael Daly, Christoph Hug, S. K. Sidorov, André Brem, Bernhard Auchmann, P. Studer, Theo A. Tervoort
Abstract
Training of accelerator magnets is a costly and time consuming process. The number of training quenches must therefore be reduced to a minimum. We investigate training of impregnated Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn Rutherford cable in a small-scale experiment named BOX (BOnding Experiment). The test involves a Rutherford cable impregnated in a meandering channel simulating the environment of a canted-cosine-theta (CCT) coil. The sample is powered using a transformer and the Lorentz force is generated by an externally applied magnetic field. The low material and helium consumption enable the test of a larger number of samples. In this article, we present training of samples impregnated with alumina-filled epoxy resins, a modified resin with paraffin-like mechanical properties, and a new tough resin in development at ETH Zürich. These new data are compared with previous results published earlier. Compared to samples with unfilled epoxy resin, those with alumina-filled epoxy show favorable training properties with higher initial quench currents and fewer training quenches before reaching 80% of the critical current.