Persistent-current magnetizations of Nb3Sn Rutherford cables and extracted strands

E.W. Collings, M.D. Sumption, C.S. Myers, Xiao Wang, D.R. Dietderich, K. Yagotyntsev, Arend Nijhuis

Research output: Contribution to journalArticleAcademicpeer-review

43 Downloads (Pure)

Abstract

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.
Original languageEnglish
Article number012037
JournalIOP Conference Series: Materials Science and Engineering
Volume279
Issue number1
DOIs
Publication statusPublished - 2017

Fingerprint Dive into the research topics of 'Persistent-current magnetizations of Nb3Sn Rutherford cables and extracted strands'. Together they form a unique fingerprint.

Cite this