Status Of Cryogenics For The Lep200 Energy Upgrade Project At Cern

The cryogenics for the LEP200 project covers the liquid helium bath cooling requirements of about 200 superconducting RF acceleration cavities to be installed in the ring tunnel of CERN's electron-positron collider LEP. It includes two cryoplants of 6 kW refrigeration capacity, four of 12 kW, about 2.6 km of transfer lines with actively cooled, flexible screens, and a helium inventory of about 80'000 Nm3. At present all equipment is ordered; about one quarter is installed and operational. Special design features needed to cope with space problems in the existing pit/tunnel system are presented and first operational experience from running the two 6 kW plants with 550 m of transfer lines and a number of cavities is reported.