The ISIS Penning Ion Source and the Volume Ion Sources from Frankfurt and DESY for H− Production

H− ion source development work at Rutherford Appleton Laboratory (RAL), the Institut fur Angewandte Physik (IAP) in Frankfurt and the Deutsches Elektronen‐Synchrotron (DESY) will be described, along with future avenues of research. The most recent values of important parameters for each ion source will be presented in the context of next generation particle accelerators, particularly the proposed European Spallation Source (ESS). A brief progress report on the ISIS RFQ test stand, on which many of the RAL ion source measurements were taken, will be included.