Significant progress achieved in the superconducting rotating proton therapy systemt at Hefei National Comprehensive Science Center on November 22. The core component, the 360° rotating gantry, has successfully completed its engineering debugging, with key parameter indicators fully meeting treatment requirements.

Fig.1：Integrated Assembly Diagram of the Rotating Gantry

After multiple rounds of technical challenges, HFCIM has successfully addressed key technical issues such as the high-precision and high-stability drive system for large rotating devices and ensuring deformation is less than 1mm under large-span support. By adopting a drive system with a large ring gear and dual active gears, the test results show that the rotating gantry can achieve a positioning accuracy of 0.1° within the 360° range, ensuring smooth and reliable operation. The center point accuracy reaches 0.8mm (±0.4mm), and the emergency stop angle at the highest speed of 1rpm (6°/s) is 2.85°, surpassing the requirements of the international IEC60601-2-64:2014 standard and the guidelines for proton and carbon ion review (emergency stop angle should be less than 3° when exceeding 1°/s). The successful commissioning of the domestically innovated and developed first 360° rotating gantry lays a solid technical foundation for accelerating the localization and industrialization of proton therapy in China.

Fig. 2: Test Results for Emergency Stop Angle at Maximum Speed of 1rpm (6°/s), Angle 2.85°

At present, the R&D of other key components of the system is progressing in an orderly manner. After multiple rounds of testing, the cyclotron has achieved a series of key technical indicators. The superconducting magnet is excited to 140A, successfully achieving a central magnetic field of 2.8T. The maximum input power of the high-frequency cavity reaches 80kW, meeting the design specifications. The beam has been successfully extracted from the ion source, laying the foundation for  beam commission.