ECLOUD’18: Proceedings of the Joint INFN-CERN-ARIES Workshop on Electron-Cloud Effects

This report contains the proceedings of the sixth electron-cloud workshop, ECLOUD'18, held, from 3 to 7 June 2018 at La Biodola (Isola d'Elba) Italy. The ECLOUD’18 workshopreviewed many recent electron-cloud (EC) observationsat existing storage rings, EC predictions for future accelerators, and various advanced electron-cloud studies. The existence of ECeffects in many frontier accelerators has by now been firmly established. It isa consequence of the strong coupling between a positively charged particle beam and a cloud of electrons that almost inevitablybuilds upinside the vacuum chamber. The EC causes various effects limiting accelerator performance, such asbeam instabilities, beam losses, emittance growth, increases in vacuum pressure, additional heat load on the vacuum chamber wallsinside cold magnets, and interference with certain types of beam diagnostics.At ECLOUD’18,recent EC studieswere presented, discussed and compared: electron-cloud observations at the LHC, SuperKEKB, CESR-TA and DAFNE; electron-cloud predictions for FAIR, NICA, EICand for the FCCand other machines; electron-cloud mitigation measures, such as clearing electrodes, graphite/carbon coatings, and chemically or laser treated surfaces; modeling of incoherent electron-cloud effects; self-consistent simulationsincluding ionized molecules; synergies with other communities like the Valencia Space Consortium and the European Space Agency, surface science experts and specialists for conventional accelerator impedance. ECLOUD’18 identified anumber of open questions and defined future R&D needs.