Abstract An H - ion source is being operated at the new 160 MeV linear injector (Linac4) of CERN accelerator complex. The source’s plasma Radio Frequency Inductively Coupled Plasma type (RF-ICP), without magnetic cusp and runs with Cs-loss compensation [1]. Vertical downward oriented filter- electron dump-dipolar fields expand over chamber, beam-formation, beam-extraction dump regions generate ...