Operation of the CSNS Penning surface H− ion source

The accelerator complex of the China Spallation Neutron Source (CSNS) consists of a H⁻ linear accelerator (linac) and a rapid cycling synchrotron (RCS). The linac contains a Penning surface H⁻ ion source. The designed energy and the beam current of the source are 50 keV and 20 mA respectively, with a normalized root mean square (norm. rms.) emittance of 0.2π mm mrad. The manufactures and tests of the discharge chamber are in great progress. The construction of H⁻ ion source test stand has been completed, and the operation of the source is also in progress. Stable H⁻ ion beams with energy of 50 keV and current up to 50 mA are attained. Emittance measurement for the H⁻ beam is being prepared.