Speaker
Description
Future electron–positron linear colliders require nanometer-scale beams at the interaction point. At such small beam sizes, even weak transverse wakefields generated by accelerator components can affect the beam orbit and beam size and therefore cannot be neglected. The KEK Accelerator Test Facility (ATF), which is dedicated to developing nanometer-beam technologies, provides a unique opportunity to quantitatively evaluate wakefield effects on nanometer-scale beams. At ATF, experimental and numerical studies have been conducted to understand these effects. Based on these studies, the final-focus beamline has been upgraded with low-impedance vacuum components to reduce the influence of wakefields. This presentation provides an overview of wakefield studies at ATF and reports the current status of the beamline upgrade and its evaluation.