Welcome to the digital edition of the July/August 2024 issue of CERN Courier.

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. Elsewhere in this issue: Andrzej Buras identifies the six rare decays that are best placed to probe beyond the energy frontier this decade; CALET studies cosmic-ray anomalies on the International Space Station; DUNE takes shape in Ray Davis Jr’s gold mine; how to increase access to medical linacs in low- and middle-income countries; ATLAS and CMS hunt the Higgs boson’s self-interaction; and how big is a neutrino?

j CERN Courier July/August 2024