Polarized Electrons, Positrons and Ions: Source Challenges for New Accelerators

Polarized electron and ion source technology has matured significantly over the past 10 years, with developments both remarkable and subtle, that have boosted beam current, polarization and source reliability. These developments have significantly improved the physics results at existing accelerators and are often cited when discussing realistic expectations for new accelerators having more demanding beam requirements. This talk presents an (incomplete) summary of electron/ positron source development for the International Linear Collider and electron/ion source development for the Electron Ion Collider.