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Title: Effects of core type, placement, and width on the estimated interstrand coupling properties of QXF-type Nb 3Sn Rutherford cables

The coupling magnetization of a Rutherford cable is inversely proportional to an effective interstrand contact resistance R eff , a function of the crossing-strand resistance R c, and the adjacent strand resistance R a. In cored cables, R eff continuously varies with W, the core width expressed as percent interstrand cover. For a series of un-heat-treated stabrite-coated NbTi LHC-inner cables with stainless-steel (SS, insulating) cores, R eff (W) decreased smoothly as W decreased from 100%, whereas for a set of research-wound SS-cored Nb 3Sn cables, R eff plummeted abruptly and remained low over most of the range. The difference is due to the controlling influence of R c - 2.5 μΩ for the stabrite/NbTi and 0.26 μΩ for Nb 3Sn. The experimental behavior was replicated in the R eff (W)’s calculated by the program CUDI, which (using the basic parameters of the QXF cable) went on to show in terms of decreasing W that: 1) in QXF-type Nb 3Sn cables (R c = 0.26 μΩ), R eff dropped even more suddenly when the SS core, instead of being centered, was offset to one edge of the cable; 2) R eff decreased more gradually in cables with higher R c’s; andmore » 3) a suitable R eff for a Nb 3Sn cable can be achieved by inserting a suitably resistive core rather than an insulating (SS) one.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2]
  1. The Ohio State Univ., Columbus, OH (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
OSTI Identifier:
1213938
Grant/Contract Number:
SC0011721
Type:
Accepted Manuscript
Journal Name:
IEEE Transactions on Applied Superconductivity
Additional Journal Information:
Journal Volume: 25; Journal Issue: 3; Journal ID: ISSN 1051-8223
Publisher:
Institute of Electrical and Electronics Engineers (IEEE)
Research Org:
The Ohio State Univ., Columbus, OH (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; 36 MATERIALS SCIENCE; Nb3Sn; cable; magnetization; accelerator