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Title: Improved cable insulation for superconducting magnets

Conference ·
OSTI ID:10181344
; ; ; ;  [1]; ; ;  [2]
  1. Brookhaven National Lab., Upton, NY (United States)
  2. Du Pont de Nemours (E.I.) and Co., Wilmington, DE (United States)

Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/Fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where wires in neighboring turns crossed one another and where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system.

Research Organization:
Brookhaven National Lab., Upton, NY (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC02-76CH00016
OSTI ID:
10181344
Report Number(s):
BNL-48532; CONF-930511-392; ON: DE93040171; TRN: 93:020101
Resource Relation:
Conference: PAC `93: international particle accelerator conference,Washington, DC (United States),17-20 May 1993; Other Information: PBD: [1993]
Country of Publication:
United States
Language:
English