Persistent-current magnetizations of Nb₃Sn Rutherford cables and extracted strands

Journal Article · Fri Dec 01 00:00:00 EST 2017 · IOP Conference Series. Materials Science and Engineering

DOI:https://doi.org/10.1088/1757-899X/279/1/012037· OSTI ID:1602810

Collings, E. W. ^[1]; Sumption, M. D. ^[2]; Myers, C. S. ^[2]; Wang, X. ^[3]; Dietderich, D. R. ^[3]; Yagotyntsev, K. ^[4]; Nijhuis, A. ^[4]

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1. The Ohio State Univ., Columbus, OH (United States). Center for Superconducting and Magnetic Materials (CSMM), Dept. of Materials Science and Engineering
2. The Ohio State Univ., Columbus, OH (United States). Center for Superconducting and Magnetic Materials (CSMM), Dept. of Materials Science and Engineering
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Superconducting Magnet Group
4. Univ. of Twente, Enschede (Netherlands). Energy, Materials, and Systems Group

The magnetizations of eight high-gradient quadrupole cables designated HQ and QXF and a pair of strands, identical in architecture but with different effective strand diameters extracted from an HQ and a related QXF cable, were measured. In the service of field quality assessment, the cable magnetizations and losses were measured by pickup coil magnetometry at 4.2 K in face-on fields, B m , of ± 400 mT at frequencies, f, of up to 60 mHz. Based on the coupling component of loss, Q coup , the coupling magnetization M coup = Q coup /4B m was derived for a ramp rate of 7.5 mT/s. Persistent current (shielding) magnetization and loss (M sh and Q h,strand ) were measured on short pieces of extracted strand by vibrating sample magnetometry at 4.2 K. Unpenetrated M-B loops to ±400 mT and fully penetrated loops to ±14 T were obtained. M coup can be easily controlled and reduced to relatively small values by introducing cores and adjusting the preparation conditions. But in low fields near injection Nb₃Sn's high J c and correspondingly high M sh,cable may call for magnetic compensation to preserve field quality. The suitably adjusted cable and strand fully penetrated M-B loops were in reasonable accord leading to the conclusion that strand magnetization is a useful measure of cable magnetization, and that when suitably manipulated can provide input to magnet field error calculations.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: AC02-05CH11231; SC0010312; SC0011721
• OSTI ID: 1602810
• Journal Information: IOP Conference Series. Materials Science and Engineering, Vol. 279; Conference: IOP Conference Series: Materials Science and Engineering; ISSN 1757-8981
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE