Volume 346 - 23rd International Spin Physics Symposium (SPIN2018) - Parallel Session: Polarized Ion and Lepton Sources and Targets (K. Aulenbacher and C. Keith)
A bulk superconducting MgB$_2$ cylinder for holding transversely polarized targets
M. Statera,* I. Balossino, L. Barion, G. Ciullo, M. Contalbrigo, L. Del Bianco, P. Lenisa, M. Lowry, A. Sandorfi, F. Spizzo, G. Tagliente
*corresponding author
Full text: pdf
Pre-published on: 2019 August 19
Published on: 2019 August 23
Abstract
An innovative solution is being pursued for the challenging magnetic problem of producing an internal transverse field around a polarized target, while shielding out an external longitudinal field from a detector.
A hollow bulk superconductor can trap a transverse field that is present when cooled through its transition temperature, and also shield its interior from any subsequent field changes. A feasibility study with a prototype bulk MgB$_2$ superconducting cylinder is described. Promising measurements taken of the interior field retention and exterior field exclusion, together with the corresponding long-term stability performance, are reported. In the context of an electron scattering experiment, such a solution minimizes beam deflection and the energy loss of reaction products, while also eliminating the heat load to the target cryostat from current leads that would be used with conventional electromagnets.
DOI: https://doi.org/10.22323/1.346.0112
Open Access