CLIC material fatigue study: an overview of recent results

by Markus Aicheler (Ruhr-Universitaet Bochum)

Wednesday 26 Nov 2008, 16:00 → 17:00 Europe/Zurich

AT Auditorium (CERN)

The fatigue of the material of the CLIC accelerating structures due to cyclic heating arising from induced eddy currents is still considered as a critical issue. Until now it is unclear to which extent fatigue impairs the performance of the structure through the lifetime. Recent experiments showed that surface roughness and even small surface cracks did not influence the Q-factor which is linked to the RF-performance. In terms of breakdown there are several theories on how fatigue phenomena increase the breakdown rate.

An overview of four experiments to asses fatigue behavior will be presented, namely: conventional fatigue, pulsed laser, ultrasound swinger and RF-fatigue tests. The experimental results obtained so far with the help of material characterization techniques available at CERN and the Ruhr-University Bochum will be discussed, with an effort to interpret the parameters influencing the resistance of a material to pulsed surface heating.