Abstract：This article introduced two cases of vacuum failure that occurred during the operation of Siemens RDS 111 medical
cyclotrons. One failure was that the vacuum suddenly dropped significantly when the target head was rotated. Inspection found that
the sealing ring in the fixed metal disk of the target changer was damaged. After replacement, the vacuum pressure of the cyclotron
rotating target returned to normal. Another case was that when a cyclotron was used to bombard a target to produce 18F ions, the
vacuum suddenly dropped sharply. The maintenance process adopted a whole-to-part method, and the fault found was the internal
rubber gasket of the resonance frequency coupling loop was damaged. After replacing the damaged gasket, the vacuum pressure
returns to normal and the cyclotron operated normally. Repair cases in this article can provide references for cyclotron maintenance
engineers when repairing similar vacuum failure, shortening the repair time to better protect clinical medication.
潘晓强，王淑侠. RDS 111型医用回旋加速器运行中真空故障排查两例[J]. 中国医疗设备, 2021, 36(8): 174-176.
PAN Xiaoqiang, WANG Shuxia. Two Cases of the Vacuum System Troubleshooting of RDS 111 Medical Cyclotron. China Medical Devices, 2021, 36(8): 174-176.
