TESTS OF INSULATION SYSTEMS FOR Nb3SN WIND AND REACT COILS

Abstract

Tests were performed to assess the viability of several cable insulation systems for use in Nb 3 Sn accelerator magnets. Insulated stacks of cables were subjected to reaction cycles commonly used for Nb 3 Sn coils. After reaction and epoxy impregnation, current leakage between turns was measured at pressures up to 180 MPa and turn-to-turn potentials up to 500V. Systems consisting of S-2 glass, ceramic fiber, and E-glass were tested. Several methods of applying the insulation were incorporated, including sleeves and various spiral wrapped configurations. Methods of sample preparation and testing are described and results are reported.

TESTING OF NB[sub 3]SN QUADRUPOLE COILS USING MAGNETIC MIRROR STRUCTURE

“…The cable for this coil was fabricated using Fermilab's cabling machine [13] and insulated with E-glass tape using standard cable insulating technique. The acceptable performance of this insulation for Nb 3 Sn coils was confirmed previously by ten-stack sample tests [14].…”

Magnetic Mirror Structure for Testing Shell-Type Quadrupole Coils

“…The cable for this coil was fabricated using Fermilab's cabling machine [12] and insulated with E-glass tape using standard cable insulating technique. The acceptable performance of this insulation for Nb 3 Sn coils was confirmed previously by testing ten-stack samples [13] and 4-m long Nb 3 Sn dipole coil [14].…”

“…This paper describes the magnetic and mechanical design of a quadrupole mirror structure for testing single shell-type superconducting quadrupole coils with the aperture from 90 to 120 mm. The concept was experimentally verified by testing LARP 90-mm Nb 3 Sn quadrupole coils [13] in the developed mirror structure in the temperature range of 1.9-4.5 K. The fabrication experience and test results of the quadrupole mirror models are reported and discussed. …”

Analysis of Nb3Sn Accelerator Magnet Training

“…Still, coil 34 trained twice as fast as the other two though detraining was observed with further tests and more quenches. Apart from lower pre-stress levels, coil 34 differed from the other mirror coils by using a cable without a stainless -steel core and Eglass tape instead of S2-glass sleeve for cable insulation [21].…”