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Title: Electromagnetic and Mechanical Analysis of the Coil Structure for the CLAS12 Torus for 12 GeV Upgrade

The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coil case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses weremore » limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Publication Date:
OSTI Identifier:
1211610
Report Number(s):
JLAB-ACE--14-1934; DOE/OR/23177--3152
Journal ID: ISSN 1051-8223; TRN: US1500624
Grant/Contract Number:
AC05-06OR23177
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:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY SSC cable; coil structure; load; shorting coil; force imbalance; conduction cooled; superconducting magnet; magnet quench protection; double pancake; torus coil