CERN Courier Nov/Dec 2020

Roll-out from a DESY cleanroom of a 3.9 GHz RF cavity string for the European XFEL
Roll-out from a DESY cleanroom of a 3.9 GHz RF cavity string for the European XFEL. (Image: DESY)

Welcome to the digital edition of the November/December 2020 issue of CERN Courier.

Superconducting radio-frequency (SRF) cavities drive accelerators around the world, transferring energy efficiently from high-power radio waves to beams of charged particles. Behind the march to higher SRF-cavity performance is the TESLA Technology Collaboration (p35), which was established in 1990 to advance technology for a linear electron–positron collider. Though the linear collider envisaged by TESLA is yet to be built (p9), its cavity technology is already established at the European X-Ray Free-Electron Laser at DESY (a cavity string for which graces the cover of this edition) and is being applied at similar broad-user-base facilities in the US and China.

Accelerator technology developed for fundamental physics also continues to impact the medical arena. Normal-conducting RF technology developed for the proposed Compact Linear Collider at CERN is now being applied to a first-of-a-kind “FLASH-therapy” facility that uses electrons to destroy deep-seated tumours (p7), while proton beams are being used for novel non-invasive treatments of cardiac arrhythmias (p49). Meanwhile, GANIL’s innovative new SPIRAL2 linac will advance a wide range of applications in nuclear physics (p39).

Detector technology also continues to offer unpredictable benefits – a powerful example being the potential for detectors developed to search for sterile neutrinos to replace increasingly outmoded traditional approaches to nuclear nonproliferation (p30).

Elsewhere in the issue: hints of low-frequency gravitational waves (p12), feebly interacting particles to the fore (p21), PCs and the future of computing (p43), the latest from the LHC experiments (p17), and more – not least the Courier’s inaugural end-of-year cryptic crossword (p58).

j CERN Courier Nov/Dec 2020