Abstract

The need for high accelerating gradient for CLIC imposes considerable constraints on the materials of the accelerating structures.  The surfaces exposed to high pulsed RF currents are subject to cyclic thermal stresses possibly resulting in surface break up by fatigue. Since "CLIC compatible" fatigue data does not exist in literature, a comprehensive study has been initiated. A high frequency ultrasonic apparatus is used for fatigue experiments to simulate CLIC's estimated lifetime of 20 years.

Topics of presentation:
 * A number of attempts to find the optimum alloy. 
 * Techniques how to improve fatigue life of structures. Would they work in CLIC? 
 * What is the damage criteria of CLIC structures? How does it fit with collected fatigue data?