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

Abstract

This paper describes the design and parameters of a quadrupole mirror structure for testing the mechanical, thermal and quench performance of single shell-type superconducting quadrupole coils at field, current and force levels similar to that of real magnet. The concept was experimentally verified by testing two quadrupole coils, previously used in quadrupole models, in the developed mirror structure in the temperature range from 4.5 to 1.9 K. The coils were instrumented with voltage taps, heaters, and strain gauges to monitor their mechanical and thermal properties and quench performance. A new quadrupole coil made of improved Nb 3 Sn RRP-108/127 strand and cable insulation based on E-glass tape was also tested using this structure. The fabrication and test results of the quadrupole mirror models are reported and discussed.

Magnetic Mirror Structure for Testing Shell-Type Quadrupole Coils

“…All these models used regular TQ coils made of RRP-54/61 Nb 3 Sn strand with the only difference that the poles in coil #19 in TQM01 were bronze whereas the coils used in TQC02E and TQS02a had Ti poles. An excellent consistency of coil training in the mirror and quadrupole models was found [17].…”

PERFORMANCE OF NB[sub 3]SN QUADRUPOLE MAGNETS UNDER LOCALIZED THERMAL LOAD

“…In order to perform independent TQ coil tests, a magnetic mirror structure was designed and built at Fermilab. The details of the magnetic and mechanical designs and quench performance are summarized in [17]. One of the mirror models -TQM02 was equipped with the strip heaters to evaluate the RRP coil performance under the localized heat load.…”

“…Details of the coil insulation are given in [17]. The assumptions on the material properties were the same as for the 120-mm quadrupole above.…”

Comparison Between ${\hbox {Nb}}_{3}{\hbox {Al}}$ and ${\hbox {Nb}}_{3}{\hbox {Sn}}$ Strands and Cables for High Field Accelerator Magnets

“…For the last decade, several different types of Nb 3 Sn strands were manufactured for, and have been successfully used for, high field accelerator magnets [5]. But it seems the Nb 3 Sn Rutherford cables are still in an R&D stage for the application to high field accelerator magnets, and not all magnets made with Nb 3 Sn are completely trouble free [6].…”