Zhao, Y. Calabretta, L. Chen, G. Karamyshev, O. Karamysheva, G.A. Shirkov, G. Xu, S.W. JACoW Publishing Geneva, Switzerland 978-3-95450-205-9 10.18429/JACoW-Cyclotrons2019-MOP002 English 24-26 MOP002 ion-source cyclotron proton extraction experiment Contribution to a conference proceedings 2020 2020-06 https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP002 http://jacow.org/cyclotrons2019/papers/mop002.pdf A 200MeV compact superconducting cyclotron, named SC200, for proton therapy is under development by collaboration of ASIPP (Hefei, China) and JINR (Dubna, Russia). The ion source is a significant subsystem of the cyclotron. A hot cathode internal ion source has been designed and tested for SC200 cyclotron. The ion source has been successfully arc discharged on the test bench. The extracted beam current has been measured over 100 uA and filament lifetime of ion source exceeded 100 h, which indicated that the ion source meets the design requirements. The stability of the filament under strong magnetic field has also been tested and the differences between the two kinds of filament are compared.