Test samples and infrastructure for accelerator magnet developments

TL;DR

This paper emphasizes the importance of specialized test samples and infrastructure to better understand quenching in accelerator magnets, advocating for emulation of local conditions to improve magnet performance and development.

Contribution

It proposes a focused approach using small samples and controlled environments to investigate quench phenomena, highlighting current limitations and the need for improved facilities.

Findings

Local emulation of conditions can improve understanding of quench behavior

Current techniques are inadequate for comprehensive quench studies

Enhanced facilities are necessary for reliable magnet development

Abstract

LHC still does not operate at full energy due to training features in magnets. Higher field practical superconductors (Nb3Sn) show much worse training behavior than NbTi. Most magnet performance issues relate to quenching, and it is this phenomenon and its dependencies that need to be understood for us to succeed addressing them in magnets. For pragmatic and scientific reasons underlying mechanisms are hard to investigate in real magnets. Available data suggest that emulating local conditions at quench location may be enough to arrive at a good understanding of what drives observed behavior. "Local" conditions imply emulation by small samples of cables/"stacks" powered within a facility with controllable conditions, including external magnetic and force fields. This paper argues about the necessity of this approach, while reminding current understanding and directions of quench studies, and pointing out inadequacy of available techniques. Improved facilities and change of perspective are required for consistent and affordable development.