Design, Construction, and Test Arrangement of a Fast-Cycling HTS Accelerator Magnet

Design, fabrication, and assembly of a novel fast-cycling accelerator magnet is presented. A short-sample magnet is powered with a single-turn HTS cable capable to carry 80-kA current up to a temperature of 20 K. This allows for a (13-15) K margin when using the operational temperature of (5-7) K. The availability of such a wide temperature margin for a fast cycling magnet constitutes the most necessary parameter for prevention and control of the fast-cycling magnet quench. Therefore, the HTS conductors have unsurpassed advantage over the LTS ones for which the maximum temperature margin is typically 2 K. The maximum possible generated field in the 40-mm test magnet gap is 1.75 T. The applied conventional leads and the power supply, however, allow only for the sin-wave 24-kA current of 20-Hz repetition rate, thus limiting magnet tests to the B-field of 0.5 T with a maximum cycling rate of 20 T/s. The critical aspects of cable construction and the splicing connection to the power leads are described. Tentative power losses of the proposed HTS-based accelerator magnet in possible applications for the proton and muon accelerators are presented.