CERN Courier May/Jun 2020

Composite Cu/Nb3Sn multi-filamentary strands (1 mm diameter) for new accelerator magnets.
Composite Cu/Nb3Sn multi-filamentary strands (1 mm diameter) for new accelerator magnets. (Image: Maximilien Brice/CERN)

Welcome to the digital edition of the May/June 2020 issue of CERN Courier.

This month’s issue looks at the latest progress in niobium-tin (Nb3Sn) accelerator magnets for high-energy exploration. Discovered to be a superconductor more than half a century ago, and already in widespread commercial use in MRI scanners and employed on a giant scale in the under-construction ITER fusion experiment, it is only recently that high-performance accelerator magnets made from Nb3Sn have been mastered. The first use of Nb3Sn conductor in particle physics will be the High-Luminosity LHC (HL-LHC), for which the first Nb3Sn dipole and quadrupole magnets have recently been tested successfully at CERN and in the US. As our cover feature describes, the demonstration of Nb3Sn in the HL-LHC also serves as a springboard to future hadron colliders, enabling physicists to reach significantly higher energies than are possible with present-generation niobium-titanium accelerator magnets. To this end, CERN and the US labs are achieving impressive results in driving up the performance of Nb3Sn conductor in various demonstrator magnets.

Sticking with accelerators, this issue also lays out the possible paths towards a high-energy muon collider – long considered a dream machine for precision and discovery, but devilishly difficult in its details. We also describe the rapid progress being made at synchrotron X-ray sources, arguably the most significant application of accelerator science in recent decades, towards understanding the molecular structure of the SARS-CoV-2 virus. The importance of accelerators for neutron science is a theme of the Viewpoint article, and, in addition to the Courier’s regular coverage of the news, conferences and reviews, this issue includes reports on how high-energy physicists are responding to the COVID-19 pandemic.

j CERN Courier May/Jun 2020