Arnau-Izquierdo, G.

Paper	Title	Page
WEPMN072	Material Selection and Characterization for High Gradient RF Applications	2197
	M. Taborelli, G. Arnau-Izquierdo, S. Calatroni, S. T. Heikkinen, T. Ramsvik, S. Sgobba, W. Wuensch CERN, Geneva
	The selection of candidate materials for the accelerating cavities of the Compact LInear Collider (CLIC) is carried out in parallel with high power RF testing. The DC breakdown field of copper, copper alloys, refractory metals, titanium and aluminium have been measured with a dedicated setup. Higher maximum fields are obtained for refractory metals and for titanium, which exhibits important damages after conditioning. Fatigue behaviour of copper alloys has been studied for surface and bulk by pulsed laser irradiation and ultrasonic excitation, respectively. The selected copper alloys show consistently higher fatigue resistance than copper in both experiments. RF tests are planned. In order to obtain the best local properties a bi-metallic assembly is being studied for the accelerating structures. The mechanical strength of junctions of molybdenum and copper-zirconium C15000, made either by Hot Isostatic Pressing or explosion bonding was evaluated. The reliability of the results obtained with either technique should be improved. Testing in DC and RF is continued in order to select materials for a bi-metal exhibiting superior properties with respect to the combination C15000-Mo.
FROBC01	30 GHz High-Gradient Accelerating Structure Test Results	3818
	J. A. Rodriguez, G. Arnau-Izquierdo, R. Corsini, S. Doebert, R. Fandos, A. Grudiev, I. Syratchev, M. Taborelli, F. Tecker, P. Urschutz, W. Wuensch CERN, Geneva H. Aksakal, Z. Nergiz Ankara University, Faculty of Sciences, Tandogan/Ankara M. Johnson UU/ISV, Uppsala O. M. Mete Ankara University, Faculty of Engineering, Tandogan, Ankara
	The CLIC study is high power testing accelerating structures in a number of different materials and accelerating structure designs to understand the physics of breakdown, determine the appropriate scaling of performance and in particular to find ways to increase achievable accelerating gradient. The most recent 30 GHz structures which have been tested include damped structures in copper, molybdenum, titanium and aluminum. The results from these new structures are presented and compared to previous ones to determine dependencies of quantities such as achievable accelerating gradient, pulse length, power flow, conditioning rate and breakdown rate.
	Slides