Dou, G.L. JACoW Publishing Geneva, Switzerland 2673-5482 978-3-95450-212-7 10.18429/JACoW-CYCLOTRONS2022-WEAO02 English 152-155 simulation cyclotron extraction injection emittance Contribution to a conference proceedings 2023 2023-10 https://doi.org/10.18429/JACoW-CYCLOTRONS2022-WEAO02 https://jacow.org/cyclotrons2022/papers/weao02.pdf Since 2020, HIMM (Heavy Ion Medical Machine) facilities in both Wuwei and Lanzhou cities have been installed and put into clinical application or commissioning experiments. As an injector cyclotron (IC), HIMM-IC can provide 6.8 MeV/10 eµA 12C⁵⁺ beam for the synchrotron. Nevertheless, in terms of better beam quality and operation efficiency, HIMM-IC design still has a lot of room for improvement. We used OPAL simulation program to complete the 3D multi-particle dynamics simulation of HIMM-IC including the space charge effect. And the results show that it is in good agreement with the actual experimental measurements.