Wuensch, W.

Paper	Title	Page
MOPP028	Technical Specification for the CLIC Two-Beam Module	607
	G. Riddone, H. Mainaud Durand, D. Schulte, I. Syratchev, W. Wuensch, R. Zennaro CERN, Geneva R. Nousiainen HIP, University of Helsinki A. Samoshkin JINR, Dubna, Moscow Region
	The 2-m long CLIC module comprises four decelerating structures and two quadrupoles forming a FODO cell. Each decelerating structure powers two accelerating structures. Some accelerating structures are removed at regular intervals to liberate space for a quadrupole of a FODO lattice. The present layout of the standard and special modules is presented as well as the status of the system integration. The main requirements for the different sub-systems (alignment, supporting, stabilization, cooling and vacuum) are introduced together with the major integration constraints. For the key components the specification on pre-alignment and beam-based alignment tolerances is also recalled as well as their influence on the requirements of other sub-systems. For example the required stable thermal behavior and the tight tolerances of accelerating structure (the requirements for the accelerating structure pre-alignment is 0.014 mm at 1? ) in the CLIC linac largely directly the sizing and integration of the cooling system. The paper also covers the main issues related to the module integration in the tunnel. In the last part, the critical issues and future activities are summarized.
MOPP095	Advanced Experimental Techniques for RF and DC Breakdown Research	775
	J. W. Kovermann RWTH, Aachen S. Calatroni, A. Descoeudres, T. Lefevre, W. Wuensch CERN, Geneva
	Advanced experimental techniques are being developed to do in-situ analysis of DC and RF breakdowns. First measurements with a specially built spectrometer have been made with a DC spark setup at CERN and with CLIC accelerating structures in the 30GHz power test facility. This spectrometer measures the light intensity development during a breakdown for narrow wavelength intervals in the visible and near infrared range which will give information about the involved elements, temperature and plasma parameters and eventually precursors of a breakdown. Planned experiments for X-ray spectroscopy and imaging, measurements of RF-signals and ion and electron energy distribution and infrared imaging of breakdown sites are presented.
WEPP084	Fabrication of a Quadrant-type Accelerator Structure for CLIC	2716
	T. Higo, Y. Higashi, H. Kawamata, T. T. Takatomi, K. Ueno, Y. Watanabe, K. Yokoyama KEK, Ibaraki A. Grudiev, G. Riddone, M. Taborelli, W. Wuensch, R. Zennaro CERN, Geneva
	In order to heavily damp the higher order modes of an accelerator structure for CLIC, two kind of damping mechanisms are implemented in one of the designs. Here each cell is equipped with electrically coupled damping channels in addition to the magnetically coupled waveguides. This design requires an assembly of longitudinally cut four quadrants to form a structure and the parts are necessarily made with milling. Since KEK has developed a high-precision machining of X-band accelerator cells with milling and turning at the same time, the experience was extended to the milling of this quadrant. Firstly, the fabrication test of a short quadrant was performed with multiple vendors to taste the present-day engineering level of milling. Following this, a full-size quadrant is also made. In this course, some of the key features are addressed, such as flatness of the reference mating surfaces, alignment grooves, 3D profile shape of the cells, surface roughness and edge treatment. In this paper, these issues are discussed from both fabrication and evaluation point of views.
THXM01	CLIC Accelerating Structure Development	2922
	W. Wuensch CERN, Geneva
	One of the most important objectives of the CLIC (Compact Linear Collider) study is to demonstrate the design accelerating gradient of 100 MV/m in a fully featured accelerating structure under nominal operating conditions including pulse length and breakdown rate. The development and testing program which has been put into place to achieve this objective is described. Recent advances in understanding and quantifying the effects which limit the accelerating gradient are presented.
	Slides
WEPP139	The CTF3 Two-beam Test-stand Installation and Experimental Program	2821
	V. G. Ziemann, T. J.C. Ekelöf, M. Johnson, R. J.M. Y. Ruber UU/ISV, Uppsala H.-H. Braun, S. Doebert, G. Geschonke, G. Riddone, J. P.H. Sladen, I. Syratchev, W. Wuensch CERN, Geneva
	The Two-beam Test-stand in CTF3 will be used to investigate the power-generation and accelerating structures for the Compact Linear Collider CLIC. We report on its design and construction which was recently completed and discuss the imminent commissioning phase as well as the following experimental program that initially will be devoted to the test of power generation structures in the drive-beam.