Insulators rather than conductors. Pillars rather than cavities. Microns rather than centimetres. Over the past 30 years, a handful of research groups have been quietly reimagining the electron linac in miniature. Their work is developing rapidly, with focusing, bunching and net acceleration over hundreds of optical cycles all now demonstrated “on chip”. This is acceleration, but not as we know it (p35).

This research is no scholarly abstraction. Tens of thousands of conventional electron linacs are used in medicine and industry. In this edition’s interview, International Cancer Expert Corps’ Manjit Dosanjh and CERN’s Steinar Stapnes tell the Courier about the need to increase access to medical linacs in low- and middle-income countries. Their newly funded project is based on open science and international cooperation – and it will require the full toolkit of the experimental high-energy physicist (p46).

Elsewhere on these pages: Andrzej Buras identifies the six rare decays that are best placed to probe beyond the energy frontier this decade (p30); CALET studies cosmic-ray anomalies on the International Space Station (p24); DUNE takes shape in Ray Davis Jr’s gold mine (p41); ATLAS and CMS hunt the Higgs boson’s self-interaction (p7); Wolfgang Lerche reviews On the Origin of Time (p49); Silvia Pascoli on the next 10 years in astroparticle physics (p45); electroweak delights from Moriond (p18); and how big is a neutrino? (p8).

Read the digital edition of this new issue on the CERN Courier website.