Fabrication and Test of TQS01—A 90 mm ${\rm Nb}_{3}{\rm Sn}$ Quadrupole Magnet for LARP

Abstract

In support of the development of a large-aperture Nb 3 Sn superconducting quadrupole for the Large Hadron Collider luminosity upgrade, two models (TQS and TQC) with a 90-mm aperture are being constructed at LBNL and FNAL within the framework of the US LHC Accelerator Research Program (LARP). These models use two identical Nb 3 Sn coils but have different coil support structures. This paper describes the fabrication, assembly, cool-down and test of TQS01-a model based on key and bladder technology with supporting iron yoke and an aluminum shell. Comparison of the test measurements with design expectations is also reported.

Measurements of Nb3Sn conductor dimension changes during heat treatment

“…The heat treatment cycles of Nb 3 Sn superconductor are optimized to achieve high critical current (I c ) and therefore are often very long. The HT process, optimized for both high critical current and high stability current [8] in LARP magnets with 90-mm aperture [1][2][3][9][10] is depicted in Figure 1. The reaction cycle was tested on strand and cable samples and short Technological Quadrupole (TQ) magnets [9][10] with the same conductor (OST RRP 54/61).…”

Development and Test of LARP Technological Quadrupole Models of TQC Series

“…TQC01b [8] contained two coils previously used in TQC01a and two coils used in TQS01a [3]. The magnet was assembled with higher coil azimuthal preload and consequently reached higher currents at 4.5K than TQC01a.…”

Field Quality Measurements and Analysis of the LARP Technology Quadrupole Models

“…Because of larger Lorentz forces a part of coil prestress is provided by collar interference with the iron yoke. The TQS magnet is based on the bladder and keys technology, where the coil is prestressed by means of the iron pads and thermal shrinkage of outer shell [5].…”