2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41157The physics potential of an e+e- linear collider can be significantly enhanced if both the electron and positron beams are polarised. Low energy running at the Z-resonance or close to the W-pair threshold is particularly attractive with polarised positrons. This note discusses the experimental aspects and physics opportunities of both low energy running and positron polarisation.11 pages, 4 figures, contribution to Snowmass2001 workshop (E3004)High Energy Physics - PhenomenologyHigh Energy Physics - ExperimentAccelerator Physicstext