Training performance of Nb3Sn Rutherford cables in a channel with a wide range of impregnation materials

TL;DR

This study investigates the training performance of impregnated Nb3Sn Rutherford cables using various impregnation materials in a small-scale experimental setup, aiming to reduce training quenches in accelerator magnets.

Contribution

It introduces new impregnation materials and compares their training performance to previous results, highlighting improvements in initial quench currents and reduced quenches.

Findings

Alumina-filled epoxy improves initial quench currents.

Fewer training quenches with alumina-filled epoxy.

New resin materials show promising training properties.

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 Nb3Sn Rutherford cable in a small-scale 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 Z\"urich. 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.