Development of an arc discharged multicusp negative hydrogen ion source for medical cyclotrons

A volume based filament driven arc-discharge type multicusp ion source is designed and developed for the generation of negative hydrogen ions (H-). This paper describes the source magnetic field configuration, filter magnetic field profile, and other design features. The performance of the ion source has been studied under different operating parameters, such as filament current, arc current, gas flow rate, and plasma and puller voltages. The optimized ion source operating condition has been established, and source performance in terms of output beam current and beam size has been evaluated with different operating parameters. With a 12.0 mm extraction aperture diameter, a beam current of 1.2 mA has been achieved with a normalized emittance of 0.38 π mm-mrad at 25 keV.