• H. Büttig, A. Arnold, A. Büchner, M. Freitag, U. Lehnert, P. Michel, R. Schurig, G.S. Staats, J. Teichert, J. Voigtländer, A. Winter
  FZD, Dresden

The RF-system of the superconducting electron LINAC ELBE (40 MeV, 1 mA CW) is in permanent operation since 2001 without mentionable problems but it is not completely free of RF-trips. Experience gained within eight years of operation shows that the better the RF-components were conditioned the better is their electrical stability during long time operation. To be prepared for a future ELBE upgrade several test benches have been built to study the performance of RF-amplifiers, RF-couplers and waveguide windows. A resonant ring (travelling wave resonator) allows component tests with RF power up to 100 kW in continuous wave (CW) mode and 200 kW in pulsed mode. The ring, driven by a 10 kW CW klystron is equipped with different sensors to detect light, temperatures and to produce infrared images of waveguide windows. A test bench with a waveguide sliding short is used to run component tests at full reflections (all phases). In 2008 the prototype of a 30 kW IOT–based RF transmitter was installed and connected to an ELBE cavity. The experience gained during routine FEL operation is used to improve the design of the high voltage power converter of the IOT transmitter.