Progress of long-time operation and industrial use of negative ion source for particle accelerator

Negative ion source for particle accelerators is currently widely used in from basic science to the medical and industrial fields. J-PARC, one of the large proton accelerator facilities using negative ions, currently supplies negative hydrogen ion beams of about 50 mA to the accelerator for three consecutive months using a high-frequency driven ion source. In addition, it has a beam current feedback system function for keeping the beam current of the ion source constant, and realizes automatic operation that does not require an operator. The negative hydrogen ion source for J-PARC generates high-intensity beams and has sufficient life and stability as a practical machine, greatly contributing to the progress of a wide range of cutting-edge researches conducted at J-PARC. (A.O.)