• X.T. Yang, D.Z. Guo, C.Y. Hao, S.J. Hou, Z.J. Hu, Y.S. Jia, M.L. Lou, S.M. Lv, X.L. Ma, J. Meng, Z.S. Nie, Z.W. Niu, W.S. Yang, Z.M. You, J.H. Zhang, Y.G. Zhao
  IMP, Lanzhou

The vacuum system of HIRFL is a large and complex system. HIRFL consists of two ECR ion sources, a sector focus cyclotron (SFC), a separate sector cyclotron (SSC) and a multipurpose cooling storage ring system which has a main ring (CSRm) and an experiment ring (CSRe). Several beam lines connect these accelerators together and transmit various heavy ion beams to more than 10 experiment terminals. According to the requirements of the ion acceleration and ion lifetime, the working pressure in each accelerator is different. SFC is nearly 50 years old. After upgrade, the working pressure in SFC is improved from 10E-6mbar to 10E-8mbar. The pressure in SSC which was built in 1980s reaches the same level. The cooling storage ring system with a length of 500m came into operation in 2007. The average pressure in CSRm and CSRe is 5E-12mbar and 8E-12mbar respectively. Different designs were adopt for vacuum system of dozens beam lines to meet various experiment terminals requirement. For instance, some shockproof measures have to be taken for the heavy ion microbeam facility. A clean and large throughput differential pumping system was built for the Gas-filled Recoil Separator and so on.