Superconducting Solenoid System with Adjustable Shielding Factor for Precision Measurements of the Properties of the Antiproton

This is the authors' abstract. We don't add key points for this paper.

In high-energy physics, Penning traps are used to make very precise mass measurements, determine fundamental constants, and test symmetries. Magnetic field noise limits trap performance, though. A superconducting self-shielding coil can reduce magnetic field fluctuations, but technical difficulties make high shielding factors difficult to achieve in practice. This work describes a design for a coil system with adjustable shielding factor that overcomes many of these difficulties. In the BASE experiment at CERN, the authors use this design to achieve fourfold improvement in the precision of antiproton-to-proton charge-to-mass comparisons.